### Install Dependencies

Source: https://github.com/databendlabs/databend-docs/blob/main/README.md

Run this command to install project dependencies before starting local development.

```bash
yarn
```

--------------------------------

### Clone and Start Iceberg Quick Start Environment

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/cn/sql-reference/00-sql-reference/30-table-engines/02-iceberg.md

Clone the Iceberg quick start repository and launch the necessary Docker services. Ensure Docker and Docker Compose are installed beforehand.

```bash
git clone https://github.com/databendlabs/iceberg-quick-start.git
cd iceberg-quick-start
docker compose up -d
```

--------------------------------

### Create Database Example

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/cn/sql-reference/10-sql-commands/00-ddl/00-database/ddl-alter-database.md

Example of creating a database before renaming it.

```sql
CREATE DATABASE DATABEND
```

--------------------------------

### Show Databases Example

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/cn/sql-reference/10-sql-commands/00-ddl/00-database/ddl-alter-database.md

Example of showing existing databases.

```sql
SHOW DATABASES
```

--------------------------------

### Launch MinIO Container

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/tutorials/operate-and-recover/bendsave.md

Starts a MinIO container with specified access keys and ports. Ensure Docker is installed.

```bash
docker run -d --name minio \
  -e "MINIO_ACCESS_KEY=minioadmin" \
  -e "MINIO_SECRET_KEY=minioadmin" \
  -p 9000:9000 \
  -p 9001:9001 \
  minio/minio server /data \
    --address :9000 \
    --console-address :9001
```

--------------------------------

### Create and Insert Data for PIVOT Example

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/cn/sql-reference/10-sql-commands/20-query-syntax/05-query-pivot.md

Creates a 'monthly_sales' table and inserts sample data to demonstrate the PIVOT operation. This setup is required before applying PIVOT.

```sql
-- Create monthly_sales table
CREATE TABLE monthly_sales(
  empid INT,
  amount INT,
  month VARCHAR
);

-- Insert sales data
INSERT INTO monthly_sales VALUES
  (1, 10000, 'JAN'),
  (1, 400, 'JAN'),
  (2, 4500, 'JAN'),
  (2, 35000, 'JAN'),
  (1, 5000, 'FEB'),
  (1, 3000, 'FEB'),
  (2, 200, 'FEB'),
  (2, 90500, 'FEB'),
  (1, 6000, 'MAR'),
  (1, 5000, 'MAR'),
  (2, 2500, 'MAR'),
  (2, 9500, 'MAR'),
  (1, 8000, 'APR'),
  (1, 10000, 'APR'),
  (2, 800, 'APR'),
  (2, 4500, 'APR');
```

--------------------------------

### Setup Dependencies and Compile Databend

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/developer/20-community/00-contributor/00-building-from-source.md

Navigate to the Databend directory, install necessary dependencies, and add Cargo's bin directory to your PATH.

```shell
cd databend
make setup -d
export PATH=$PATH:~/.cargo/bin
```

--------------------------------

### Example: Create Table, Roles, Users, Masking Policy, and Apply Policy

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/10-sql-commands/00-ddl/12-mask-policy/create-mask-policy.md

Demonstrates the full lifecycle of creating and applying a masking policy, including table setup, role creation, user management, policy definition, and column association.

```sql
-- Create a table and insert sample data
CREATE TABLE user_info (
    user_id INT,
    phone  VARCHAR,
    email VARCHAR
);

INSERT INTO user_info (user_id, phone, email) VALUES (1, '91234567', 'sue@example.com');
INSERT INTO user_info (user_id, phone, email) VALUES (2, '81234567', 'eric@example.com');

-- Create a role
CREATE ROLE 'MANAGERS';
GRANT ALL ON *.* TO ROLE 'MANAGERS';

-- Create a user and grant the role to the user
CREATE USER manager_user IDENTIFIED BY 'databend';
GRANT ROLE 'MANAGERS' TO 'manager_user';

-- Create a masking policy that expects an extra column
CREATE MASKING POLICY contact_mask
AS
  (contact_val nullable(string), phone_ref nullable(string))
  RETURNS nullable(string) ->
  CASE
  WHEN current_role() IN ('MANAGERS') THEN
    contact_val
  WHEN phone_ref LIKE '91%' THEN
    contact_val
  ELSE
    '*********'
  END
  COMMENT = 'mask contact data with phone check';

-- Associate the masking policy with the 'email' column
ALTER TABLE user_info
MODIFY COLUMN email SET MASKING POLICY contact_mask USING (email, phone);

-- Associate the masking policy with the 'phone' column
ALTER TABLE user_info
MODIFY COLUMN phone SET MASKING POLICY contact_mask USING (phone, phone);

-- Query with the Root user
SELECT user_id, phone, email FROM user_info ORDER BY user_id;
```

```text
     user_id     │        phone     │       email      │
 Nullable(Int32) │ Nullable(String) │ Nullable(String) │
─────────────────┼──────────────────┼──────────────────┤
               1 │ 91234567         │ sue@example.com  │
               2 │ *********        │ *********        │
```

--------------------------------

### Databend Server Startup Information

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/developer/20-community/02-rfcs/20220721-new-logging.md

This is an example of the information displayed when starting the Databend server with the new logging configuration. It includes version, log status, storage details, and connection information.

```shell
Databend Server starting at xxxxxxx (took x.xs)

Information

version: v0.7.128-xxxxx
logs:
  file:   enabled dir=./databend/logs level=DEBUG
  stderr: disabled (set LOG_STDERR_ON=true to enable)
storage: s3://endpoint=127.0.0.1:1090,bucket=test,root=/path/to/data
metasrv: embed

Connection

MySQL:             mysql://root@localhost:3307/xxxx
clickhouse:        clickhouse://root@localhost:9000/xxxx
clickhouse (HTTP): http://root:@localhost:9001

Useful Links

Documentation:    https://docs.databend.com
Looking for help: https://github.com/databendlabs/databend/discussions
```

--------------------------------

### Example: Creating and Using Databases and Tables

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/10-sql-commands/00-ddl/00-database/ddl-use-database.md

Demonstrates the workflow of creating databases, switching between them using the USE command, creating tables, inserting data, and querying data within the selected database.

```sql
-- Create two databases
CREATE DATABASE database1;
CREATE DATABASE database2;

-- Select and use "database1" as the current database
USE database1;

-- Create a new table "table1" in "database1"
CREATE TABLE table1 (
  id INT,
  name VARCHAR(50)
);

-- Insert data into "table1"
INSERT INTO table1 (id, name) VALUES (1, 'John');
INSERT INTO table1 (id, name) VALUES (2, 'Alice');

-- Query all data from "table1"
SELECT * FROM table1;

-- Switch to "database2" as the current database
USE database2;

-- Create a new table "table2" in "database2"
CREATE TABLE table2 (
  id INT,
  city VARCHAR(50)
);

-- Insert data into "table2"
INSERT INTO table2 (id, city) VALUES (1, 'New York');
INSERT INTO table2 (id, city) VALUES (2, 'London');

-- Query all data from "table2"
SELECT * FROM table2;
```

--------------------------------

### Install Databend Go Driver

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/cn/developer/00-drivers/00-golang.md

Use 'go get' to install the official Databend Go driver. Refer to the driver overview for DSN format and connection examples.

```bash
go get github.com/databendlabs/databend-go
```

--------------------------------

### Boundary Behavior Example - Moving Average Start

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/08-window-functions/rows-between.md

Demonstrates how a moving average window frame adjusts at the beginning of a partition, showing how the window shrinks when fewer preceding rows are available.

```sql
-- For row 1: ROWS BETWEEN 2 PRECEDING AND CURRENT ROW
-- Actual window: CURRENT ROW only (no preceding rows)

-- For row 2: ROWS BETWEEN 2 PRECEDING AND CURRENT ROW
-- Actual window: 1 PRECEDING AND CURRENT ROW (only 1 preceding row exists)
```

--------------------------------

### TIME_SLICE Example with DATE

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/05-datetime-functions/time-slice.md

Demonstrates using TIME_SLICE with a DATE input to get the start and end boundaries of 4-month slices.

```sql
SELECT
    '2019-02-28'::DATE AS "DATE",
        TIME_SLICE("DATE", 4, 'MONTH', 'START') AS "start",
    TIME_SLICE("DATE", 4, 'MONTH', 'END') AS "end";


```

--------------------------------

### Create Products Table

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/07-aggregate-functions/aggregate-count-distinct.md

Sets up a sample 'products' table with product information for demonstrating aggregate functions.

```sql
CREATE TABLE products (
  id INT,
  name VARCHAR,
  category VARCHAR,
  price FLOAT
);
```

```sql
INSERT INTO products (id, name, category, price)
VALUES (1, 'Laptop', 'Electronics', 1000),
       (2, 'Smartphone', 'Electronics', 800),
       (3, 'Tablet', 'Electronics', 600),
       (4, 'Chair', 'Furniture', 150),
       (5, 'Table', 'Furniture', 300);
```

--------------------------------

### Example: Create, Drop, and UNDROP a database

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/cn/sql-reference/10-sql-commands/00-ddl/00-database/undrop-database.md

This example demonstrates the full lifecycle of creating a database, dropping it, and then successfully recovering it using the UNDROP DATABASE command.

```sql
root@localhost:8000/default> CREATE DATABASE orders_2024;

CREATE DATABASE orders_2024

0 row written in 0.014 sec. Processed 0 row, 0 B (0 row/s, 0 B/s)

root@localhost:8000/default> DROP DATABASE orders_2024;

DROP DATABASE orders_2024

0 row written in 0.012 sec. Processed 0 row, 0 B (0 row/s, 0 B/s)

root@localhost:8000/default> UNDROP DATABASE orders_2024;

UNDROP DATABASE orders_2024

0 row read in 0.011 sec. Processed 0 row, 0 B (0 row/s, 0 B/s)
```

--------------------------------

### Get Array Element by Index

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/10-semi-structured-functions/1-array/index.md

Use GET to retrieve an element from an array using its index. Example: GET([1,2,3], 1) returns 1.

```sql
GET([1,2,3], 1)
```

--------------------------------

### Start Metabase

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/guides/35-connect/02-visualization/metabase.md

Run the Metabase JAR file to start the Metabase application.

```bash
java -jar metabase.jar
```

--------------------------------

### Create and Insert Data for JOIN Examples

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/cn/sql-reference/10-sql-commands/20-query-syntax/04-query-join.md

Sets up sample tables (vip_info, purchase_records, gift, sensor_readings, hvac_mode) and populates them with data for demonstrating JOIN operations.

```sql
CREATE OR REPLACE TABLE vip_info (client_id INT, region VARCHAR);
INSERT INTO vip_info VALUES
    (101, 'Toronto'),
    (102, 'Quebec'),
    (103, 'Vancouver');

CREATE OR REPLACE TABLE purchase_records (client_id INT, item VARCHAR, qty INT);
INSERT INTO purchase_records VALUES
    (100, 'Croissant', 2000),
    (102, 'Donut',     3000),
    (103, 'Coffee',    6000),
    (106, 'Soda',      4000);

CREATE OR REPLACE TABLE gift (gift VARCHAR);
INSERT INTO gift VALUES
    ('Croissant'), ('Donut'), ('Coffee'), ('Soda');

-- ASOF 示例的物联网数据
CREATE OR REPLACE TABLE sensor_readings (
    room VARCHAR,
    reading_time TIMESTAMP,
    temperature DOUBLE
);
INSERT INTO sensor_readings VALUES
    ('LivingRoom', '2024-01-01 09:55:00', 22.8),
    ('LivingRoom', '2024-01-01 10:00:00', 23.1),
    ('LivingRoom', '2024-01-01 10:05:00', 23.3),
    ('LivingRoom', '2024-01-01 10:10:00', 23.8),
    ('LivingRoom', '2024-01-01 10:15:00', 24.0);

CREATE OR REPLACE TABLE hvac_mode (
    room VARCHAR,
    mode_time TIMESTAMP,
    mode VARCHAR
);
INSERT INTO hvac_mode VALUES
    ('LivingRoom', '2024-01-01 09:58:00', 'Cooling'),
    ('LivingRoom', '2024-01-01 10:06:00', 'Fan'),
    ('LivingRoom', '2024-01-01 10:30:00', 'Heating');
```

--------------------------------

### Get Start of Week

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/05-datetime-functions/index.md

Returns the timestamp set to the start of the week (Monday by default) for a given date or timestamp.

```sql
TO_START_OF_WEEK('2024-06-04')
```

--------------------------------

### CockroachDB Node Startup Information

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/developer/20-community/02-rfcs/20220721-new-logging.md

This example shows the output when starting a single node of CockroachDB. It includes build information, web UI and SQL connection details, log directory, and cluster status.

```shell
./cockroach start-single-node
CockroachDB node starting at 2022-07-21 06:56:04.36859988 +0000 UTC (took 0.7s)
build:               CCL v22.1.4 @ 2022/07/19 17:09:48 (go1.17.11)
WebUI:               http://xuanwo-work:8080
sql:                 postgresql://root@xuanwo-work:26257/defaultdb?sslmode=disable
sql (JDBC):          JDBC:postgresql://xuanwo-work:26257/defaultdb?sslmode=disable&user=root
RPC client flags:    ./cockroach <client cmd> --host=xuanwo-work:26257 --insecure
logs:                /tmp/cockroach-v22.1.4.linux-amd64/cockroach-data/logs
temp dir:            /tmp/cockroach-v22.1.4.linux-amd64/cockroach-data/cockroach-temp3237741659
external I/O path:   /tmp/cockroach-v22.1.4.linux-amd64/cockroach-data/extern
store[0]:            path=/tmp/cockroach-v22.1.4.linux-amd64/cockroach-data
storage engine:      pebble
clusterID:           e1ab003d-7eba-48cd-b635-7a51f40269c2
status:              restarted preexisting node
nodeID:              1
```

--------------------------------

### Start Local Preview

Source: https://github.com/databendlabs/databend-docs/blob/main/README.md

Execute this command to start a local development server for previewing documentation changes.

```bash
yarn run dev
```

--------------------------------

### Fast addr2line Setup

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/developer/20-community/00-contributor/04-how-to-profiling.md

Clone and build the `addr2line` repository to potentially speed up heap analysis from minutes to seconds. Replace the placeholder with your actual `addr2line` path.

```bash
git clone https://github.com/gimli-rs/addr2line
cd addr2line
cargo b --examples -r
cp ./target/release/examples/addr2line <your-addr2line-find-with-whereis-addr2line>
```

--------------------------------

### Get Start of Week (Default Sunday)

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/05-datetime-functions/to-start-of-week.md

Returns the start of the week for a given date or timestamp. Defaults to Sunday if mode is not specified.

```sql
SELECT
  to_start_of_week('2023-11-12 09:38:18.165575');

┌────────────────────────────────────────────────┐
│ to_start_of_week('2023-11-12 09:38:18.165575') │
├────────────────────────────────────────────────┤
│ 2023-11-12                                     │
└────────────────────────────────────────────────┘
```

--------------------------------

### Get Array Element by Index (Alias)

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/10-semi-structured-functions/1-array/index.md

ARRAY_GET is an alias for the GET function. Example: ARRAY_GET([1,2,3], 1) returns 1.

```sql
ARRAY_GET([1,2,3], 1)
```

--------------------------------

### Show Roles and Set Role Example

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/10-sql-commands/00-ddl/02-user/04-user-set-role.md

Demonstrates how to view available roles, set an active role, and then verify the change by showing roles again. Ensure the role you are setting exists.

```sql
SHOW ROLES;

┌───────────────────────────────────────────────────────┐
│    name   │ inherited_roles │ is_current │ is_default │
├───────────┼─────────────────┼────────────┼────────────┤
│ developer │               0 │ false      │ false      │
│ public    │               0 │ false      │ false      │
│ writer    │               0 │ true       │ true       │
└───────────────────────────────────────────────────────┘

SET ROLE developer;

SHOW ROLES;

┌───────────────────────────────────────────────────────┐
│    name   │ inherited_roles │ is_current │ is_default │
├───────────┼─────────────────┼────────────┼────────────┤
│ developer │               0 │ true       │ false      │
│ public    │               0 │ false      │ false      │
│ writer    │               0 │ false      │ true       │
└───────────────────────────────────────────────────────┘
```

--------------------------------

### Calculate Character Code with ORD()

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/06-string-functions/ord.md

Use the ORD() function to get the character code of a string. This example shows how to get the code for the character '2'.

```sql
SELECT ORD('2')
```

--------------------------------

### Create Products Table and Insert Data

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/10-semi-structured-functions/0-json/json-path-query-first.md

Sets up a sample table named 'products' with 'name' and 'details' columns, then populates it with product information in JSON format. This is a prerequisite for demonstrating JSON path queries.

```sql
CREATE TABLE products (
    name VARCHAR,
    details VARIANT
);

INSERT INTO products (name, details)
VALUES ('Laptop', '{"brand": "Dell", "colors": ["Black", "Silver"], "price": 1200, "features": {"ram": "16GB", "storage": "512GB"}}'),
       ('Smartphone', '{"brand": "Apple", "colors": ["White", "Black"], "price": 999, "features": {"ram": "4GB", "storage": "128GB"}}'),
       ('Headphones', '{"brand": "Sony", "colors": ["Black", "Blue", "Red"], "price": 150, "features": {"battery": "20h", "bluetooth": "5.0"}}');
```

--------------------------------

### Start Debezium Server with Docker Compose

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/guides/40-load-data/02-load-db/debezium.md

Use Docker Compose to start the debezium-server-databend service in detached mode. Ensure Docker and Docker Compose are installed.

```bash
docker-compose up -d
```

--------------------------------

### Install BendSQL using cargo-binstall

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/guides/35-connect/00-sql-clients/bendsql.md

Use this command to install BendSQL if you have `cargo-binstall` set up. Ensure Rust and Cargo are installed first.

```bash
cargo binstall bendsql
```

--------------------------------

### Prepare demo objects for task pipeline

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/guides/40-load-data/05-continuous-data-pipelines/02-task.md

Sets up a database, schema, table, and stage required for the data loading task example.

```sql
-- Create a playground schema and target table
CREATE DATABASE IF NOT EXISTS task_demo;
USE task_demo;

CREATE OR REPLACE TABLE sensor_events (
    event_time  TIMESTAMP,
    sensor_id   INT,
    temperature DOUBLE,
    humidity    DOUBLE
);

-- Stage that will store the generated Parquet files
CREATE OR REPLACE STAGE sensor_events_stage;
```

--------------------------------

### Unquoted SQL Identifiers Examples

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/cn/sql-reference/00-sql-reference/40-sql-identifiers.md

Examples of valid unquoted identifiers in Databend. These start with a letter or underscore and can contain letters, underscores, numbers, or dollar signs.

```text
mydatabend
MyDatabend1
My$databend
_my_databend
```

--------------------------------

### Example: Create, Show, and Alter Network Policy and User

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/10-sql-commands/00-ddl/12-network-policy/ddl-create-policy.md

Demonstrates creating a network policy with specific allowed and blocked IPs, then showing the created policy, creating a user, and finally associating the network policy with the user.

```sql
-- Create a network policy
CREATE NETWORK POLICY sample_policy
    ALLOWED_IP_LIST=('192.168.1.0/24')
    BLOCKED_IP_LIST=('192.168.1.99')
    COMMENT='Sample';

SHOW NETWORK POLICIES;

Name         |Allowed Ip List          |Blocked Ip List|Comment    |
-------------+-------------------------+---------------+-----------+
sample_policy|192.168.1.0/24           |192.168.1.99   |Sample     |

-- Create a user
CREATE USER sample_user IDENTIFIED BY 'databend';

-- Associate the network policy with the user
ALTER USER sample_user WITH SET NETWORK POLICY='sample_policy';
```

--------------------------------

### Get Array Size

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/10-semi-structured-functions/1-array/index.md

Use ARRAY_SIZE to get the number of elements in an array. The alias ARRAY_LENGTH can also be used. Example: ARRAY_SIZE([1,2,3]) returns 3.

```sql
ARRAY_SIZE([1,2,3])
```

--------------------------------

### Create Table and Insert Sample Data

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/07-aggregate-functions/aggregate-approx-count-distinct.md

Sets up a table named 'user_events' and populates it with sample data for demonstration purposes.

```sql
CREATE TABLE user_events (
  id INT,
  user_id INT,
  event_name VARCHAR
);

INSERT INTO user_events (id, user_id, event_name)
VALUES (1, 1, 'Login'),
       (2, 2, 'Login'),
       (3, 3, 'Login'),
       (4, 1, 'Logout'),
       (5, 2, 'Logout'),
       (6, 4, 'Login'),
       (7, 1, 'Login');
```

--------------------------------

### Example of NOT LIKE Usage

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/06-string-functions/not-like.md

Demonstrates filtering function names that start with 'tou' but do not end with '64'.

```sql
+----------+------------+
| name     | category   |
+----------+------------+
| touint16 | conversion |
| touint32 | conversion |
| touint8  | conversion |
+----------+------------+
```

--------------------------------

### Create Table and Insert Data

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/07-aggregate-functions/aggregate-min-if.md

Sets up a sample table named 'project_budgets' with project budget data for demonstration purposes.

```sql
CREATE TABLE project_budgets (
  id INT,
  project_id INT,
  department VARCHAR,
  budget FLOAT
);

INSERT INTO project_budgets (id, project_id, department, budget)
VALUES (1, 1, 'HR', 1000),
       (2, 1, 'IT', 2000),
       (3, 1, 'Marketing', 3000),
       (4, 2, 'HR', 1500),
       (5, 2, 'IT', 2500);
```

--------------------------------

### Get Start of Day

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/05-datetime-functions/index.md

Returns the timestamp set to the beginning of the day (00:00:00) for a given date or timestamp.

```sql
TO_START_OF_DAY('2024-06-04 12:30:45')
```

--------------------------------

### RANGE BETWEEN CURRENT ROW and UNBOUNDED FOLLOWING

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/08-window-functions/range-between.md

Example of a frame starting from the current row to the end of the partition.

```sql
RANGE BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
```

--------------------------------

### Example: Managing Users, Roles, and Grants

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/10-sql-commands/00-ddl/02-user/22-show-grants.md

Illustrates creating users and roles, granting roles to users, and then using SHOW GRANTS to inspect these assignments and object privileges.

```sql
-- Create a new user
CREATE USER 'user1' IDENTIFIED BY 'password';
```

```sql
-- Create a new role
CREATE ROLE analyst;
```

```sql
-- Grant the analyst role to the user
GRANT ROLE analyst TO 'user1';
```

```sql
-- Create a database
CREATE DATABASE my_db;
```

```sql
-- Grant privileges on the database to the role
GRANT OWNERSHIP ON my_db.* TO ROLE analyst;
```

```sql
-- List privileges granted to the user
SHOW GRANTS FOR user1;
```

```sql
-- List privileges granted to the role
SHOW GRANTS FOR ROLE analyst;
```

```sql
-- List privileges granted on the database
SHOW GRANTS ON DATABASE my_db;
```

```sql
-- Lists all users and roles that have been directly granted role_name.  
-- This command displays only the direct grantees of role_name. 
-- This means it lists users and roles that have explicitly received the role through a GRANT ROLE role_name TO <user_or_role> statement. 
-- It does not show users or roles that acquire role_name indirectly via role hierarchies or inheritance.
SHOW GRANTS OF ROLE analyst
```

```sql
SHOW GRANTS ON MASKING POLICY email_mask;
```

```sql
-- Inspect row access policy privileges
SHOW GRANTS ON ROW ACCESS POLICY rap_region;
```

--------------------------------

### Example: Listing User and Role Grants

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/cn/sql-reference/20-sql-functions/17-table-functions/show-grants.md

This example demonstrates creating a user and role, granting permissions, and then using SHOW_GRANTS to list authorizations for the user, role, and a stage.

```sql
-- 创建新用户
CREATE USER 'user1' IDENTIFIED BY 'password';
```

```sql
-- 创建新角色
CREATE ROLE analyst;
```

```sql
-- 将 analyst 角色授予用户
GRANT ROLE analyst TO 'user1';
```

```sql
-- 创建 stage
CREATE STAGE my_stage;
```

```sql
-- 将 stage 上的权限授予角色
GRANT READ ON STAGE my_stage TO ROLE analyst;
```

```sql
-- 列出用户的授权
SELECT * FROM SHOW_GRANTS('user', 'user1');
```

```sql
-- 列出授予角色的权限
SELECT * FROM SHOW_GRANTS('role', 'analyst');
```

```sql
-- 列出授予 stage 的权限
SELECT * FROM SHOW_GRANTS('stage', 'my_stage');
```

--------------------------------

### RANGE BETWEEN UNBOUNDED PRECEDING and CURRENT ROW

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/08-window-functions/range-between.md

Example of a frame starting from the beginning of the partition up to the current row.

```sql
RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW
```

--------------------------------

### Create Table and Insert Sample Data

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/07-aggregate-functions/aggregate-quantile-disc.md

Sets up a table named 'salary_data' and populates it with sample salary information for demonstration purposes.

```sql
CREATE TABLE salary_data (
  id INT,
  employee_id INT,
  salary FLOAT
);

INSERT INTO salary_data (id, employee_id, salary)
VALUES (1, 1, 50000),
       (2, 2, 55000),
       (3, 3, 60000),
       (4, 4, 65000),
       (5, 5, 70000);
```

--------------------------------

### Get command output

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/guides/20-self-hosted/02-deployment/02-production/70-metasrv-cli-api.md

Example output for the `kvapi::get` command, showing the state of the requested key.

```json
{
  "seq": 23,
  "meta": null,
  "data": [ 98, 97, 114 ]
}
```

--------------------------------

### Example Webhook Notification Integration

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/10-sql-commands/00-ddl/16-notification/01-ddl-create-notification.md

This example demonstrates creating a notification integration named 'SampleNotification' of type 'webhook'. It is enabled and configured to send notifications to a specified URL using GET method and a bearer token.

```sql
CREATE NOTIFICATION INTEGRATION IF NOT EXISTS SampleNotification type = webhook enabled = true webhook = (url = 'https://example.com', method = 'GET', authorization_header = 'bearer auth')
```

--------------------------------

### Create Table and Show Fields Example

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/10-sql-commands/00-ddl/01-table/show-fields.md

This example demonstrates creating a table named 'books' and then using SHOW FIELDS to inspect its columns. The output shows the field name, type, nullability, default values, and extra information.

```sql
CREATE TABLE books
  (
     price  FLOAT Default 0.00,
     pub_time DATETIME Default '1900-01-01',
     author VARCHAR
  );

SHOW FIELDS FROM books;
```

--------------------------------

### Create Table, Stream, and Insert Data

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/10-sql-commands/20-query-syntax/with-stream-hints.md

Sets up a table and a stream for demonstration purposes, then inserts initial data.

```sql
CREATE TABLE t1(a int);
CREATE STREAM s ON TABLE t1;
INSERT INTO t1 values(1);
INSERT INTO t1 values(2);
```

--------------------------------

### Create Sales Table

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/cn/sql-reference/20-sql-functions/08-window-functions/rows-between.md

Sets up a sample 'sales' table with date, product, and amount columns for demonstrating window functions.

```sql
CREATE OR REPLACE TABLE sales (
    sale_date DATE,
    product VARCHAR(20),
    amount DECIMAL(10,2)
);

INSERT INTO sales VALUES
    ('2024-01-01', 'A', 100.00),
    ('2024-01-02', 'A', 150.00),
    ('2024-01-03', 'A', 200.00),
    ('2024-01-04', 'A', 250.00),
    ('2024-01-05', 'A', 300.00),
    ('2024-01-01', 'B', 50.00),
    ('2024-01-02', 'B', 75.00),
    ('2024-01-03', 'B', 100.00),
    ('2024-01-04', 'B', 125.00),
    ('2024-01-05', 'B', 150.00);
```

--------------------------------

### Get Start of Minute

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/05-datetime-functions/index.md

Returns the timestamp set to the beginning of the minute (e.g., 12:30:00) for a given date or timestamp.

```sql
TO_START_OF_MINUTE('2024-06-04 12:30:45')
```

--------------------------------

### Create Example Table and Insert Data

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/cn/sql-reference/10-sql-commands/10-dml/dml-copy-into-location.md

Sets up a sample table named 'canadian_city_population' and populates it with data for use in subsequent examples.

```sql
-- 创建示例表
CREATE TABLE canadian_city_population (
     city_name VARCHAR(50),
     population INT
);

-- 插入示例数据
INSERT INTO canadian_city_population (city_name, population)
VALUES
('Toronto', 2731571),
('Montreal', 1704694),
('Vancouver', 631486),
('Calgary', 1237656),
('Ottawa', 934243),
('Edmonton', 972223),
('Quebec City', 542298),
('Winnipeg', 705244),
('Hamilton', 536917),
('Halifax', 403390);
```

--------------------------------

### Get Start of Hour

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/05-datetime-functions/index.md

Returns the timestamp set to the beginning of the hour (e.g., 12:00:00) for a given date or timestamp.

```sql
TO_START_OF_HOUR('2024-06-04 12:30:45')
```

--------------------------------

### Create and Describe Table

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/10-sql-commands/00-ddl/01-table/50-describe-table.md

This example demonstrates creating a table with specific column types and default values, followed by describing its structure to view the defined columns.

```sql
CREATE TABLE books
  (
     price  FLOAT Default 0.00,
     pub_time DATETIME Default '1900-01-01',
     author VARCHAR
  );

DESC books;
```

--------------------------------

### Get Unique Array Elements (Alias)

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/10-semi-structured-functions/1-array/index.md

ARRAY_UNIQUE is an alias for ARRAY_DISTINCT. Example: ARRAY_UNIQUE([1,2,2,3]) results in [1,2,3].

```sql
ARRAY_UNIQUE([1,2,2,3])
```

--------------------------------

### Create and Insert Data for LISTAGG Example

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/07-aggregate-functions/aggregate-listagg.md

Sets up a sample 'orders' table and populates it with data to demonstrate the LISTAGG function.

```sql
CREATE TABLE orders (
  customer_id INT,
  product_name VARCHAR
);

INSERT INTO orders (customer_id, product_name) VALUES
(1, 'Laptop'),
(1, 'Mouse'),
(1, 'Laptop'),
(2, 'Phone'),
(2, 'Headphones');
```

--------------------------------

### Run Kafka Docker Container

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/tutorials/ingest-and-stream/kafka-bend-ingest-kafka.md

Starts a Kafka Docker container on port 9092. Ensure Docker is installed and running.

```shell
docker run -d \
  --name kafka \
  -p 9092:9092 \
  apache/kafka:latest
```

--------------------------------

### Full Example: Ngram Index for Log Analysis

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/cn/guides/55-performance/ngram-index.md

A comprehensive example showing table creation for articles, setting up an Ngram index with gram_size=3, verifying index creation, inserting diverse data, and performing a LIKE search. It also includes EXPLAIN to verify index usage and performance metrics.

```sql
-- 为应用程序日志创建表
CREATE TABLE t_articles (
    id INT,
    content STRING
);

-- 创建一个 n-gram 索引，分词长度为 3
CREATE NGRAM INDEX ngram_idx_content
ON t_articles(content)
gram_size = 3;

-- 验证索引创建
SHOW INDEXES;
```

```sql
┌─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
│        name       │  type  │ original │            definition            │         created_on         │      updated_on     │
├───────────────────┼────────┼──────────┼──────────────────────────────────┼────────────────────────────┼─────────────────────┤
│ ngram_idx_content │ NGRAM  │          │ t_articles(content)gram_size='3' │ 2025-05-13 01:02:58.598409 │ NULL                │
└─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘
```

```sql
-- 插入测试数据：995 行不相关数据 + 5 行目标数据
INSERT INTO t_articles
SELECT number, CONCAT('Random text number ', number)
FROM numbers(995);

INSERT INTO t_articles VALUES
    (1001, 'The silence was deep and complete'),
    (1002, 'They walked in silence through the woods'),
    (1003, 'Silence fell over the room'),
    (1004, 'A moment of silence was observed'),
    (1005, 'In silence, they understood each other');

-- 使用模式匹配进行搜索
SELECT id, content FROM t_articles WHERE content LIKE '%silence%';

-- 验证索引使用情况
EXPLAIN SELECT id, content FROM t_articles WHERE content LIKE '%silence%';
```

```sql
-[ EXPLAIN ]-----------------------------------
TableScan
├── table: default.default.t_articles
├── output columns: [id (#0), content (#1)]
├── read rows: 5
├── read size: < 1 KiB
├── partitions total: 2
├── partitions scanned: 1
├── pruning stats: [segments: <range pruning: 2 to 2>, blocks: <range pruning: 2 to 2, bloom pruning: 2 to 1>]
├── push downs: [filters: [is_true(like(t_articles.content (#1), '%silence%'))], limit: NONE]
└── estimated rows: 15.62
```

--------------------------------

### Start Databend Instance with Docker

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/tutorials/getting-started/connect-to-databend-bendsql.md

Launches a Databend instance locally in a Docker container. Ensure Docker is installed and running.

```bash
docker run -d --name databend \
  -e QUERY_DEFAULT_USER=eric \
  -e QUERY_DEFAULT_PASSWORD=abc123 \
  -p 3307:3307 -p 8000:8000 -p 8124:8124 -p 8900:8900 \
  datafuselabs/databend:nightly
```

--------------------------------

### Get Start of Year

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/05-datetime-functions/index.md

Returns the timestamp set to the first day of the year (e.g., 2024-01-01) for a given date or timestamp.

```sql
TO_START_OF_YEAR('2024-06-04')
```

--------------------------------

### Create Table and Insert Data

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/07-aggregate-functions/aggregate-covar-pop.md

Sets up a sample table 'product_sales' and populates it with data for demonstrating the COVAR_POP function.

```sql
CREATE TABLE product_sales (
  id INT,
  product_id INT,
  units_sold INT,
  revenue FLOAT
);

INSERT INTO product_sales (id, product_id, units_sold, revenue)
VALUES (1, 1, 10, 1000),
       (2, 2, 20, 2000),
       (3, 3, 30, 3000),
       (4, 4, 40, 4000),
       (5, 5, 50, 5000);
```

--------------------------------

### POST /v1/query (Session Examples)

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/developer/10-apis/http.md

Demonstrates how to use session settings, such as specifying a database and configuring query execution parameters like max threads and memory usage.

```APIDOC
## POST /v1/query (Session Examples)

### Description
Using Session Settings to configure query execution.

### Method
POST

### Endpoint
`/v1/query`

### Parameters
#### Request Body
- **sql** (string) - Required - The SQL statement to execute.
- **session** (object) - Optional - Session configuration.
  - **database** (string) - Optional - The default database to use for the session.
  - **settings** (object) - Optional - Key-value pairs for session settings.
    - **max_threads** (string) - Optional - Maximum number of threads to use for query execution.
    - **max_memory_usage** (string) - Optional - Maximum memory usage allowed for the query.

#### Request Example
```bash
curl -u "user:password" \
  --request POST \
  'https://<endpoint>/v1/query/' \
  --header 'Content-Type: application/json' \
  --header 'X-DATABEND-WAREHOUSE: <warehouse>' \
  --data-raw '{
    "sql": "SELECT * FROM my_table",
    "session": {
      "database": "production",
      "settings": {
        "max_threads": "4",
        "max_memory_usage": "10737418240"
      }
    }
  }'
```
```

--------------------------------

### Get Start of Quarter

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/05-datetime-functions/index.md

Returns the timestamp set to the first day of the quarter (e.g., 2024-04-01) for a given date or timestamp.

```sql
TO_START_OF_QUARTER('2024-06-04')
```

--------------------------------

### Get Start of Month

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/05-datetime-functions/index.md

Returns the timestamp set to the first day of the month (e.g., 2024-06-01) for a given date or timestamp.

```sql
TO_START_OF_MONTH('2024-06-04')
```

--------------------------------

### BEGIN Syntax

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/10-sql-commands/00-ddl/14-transaction/begin.md

The basic syntax for starting a transaction.

```sql
BEGIN [ TRANSACTION ]
```

--------------------------------

### ARRAY_GENERATE_RANGE Function Example

Source: https://github.com/databendlabs/databend-docs/blob/main/pdf/docs.databend.en-sql.txt

Generates an array of numbers within a specified range. Supports start, stop, and step values.

```sql
SELECT ARRAY_GENERATE_RANGE(1, 10, 2);
-- returns [1, 3, 5, 7, 9]
```

--------------------------------

### Create and Insert Data into a Table

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/16-system-functions/fuse_snapshot.md

Sets up a sample table and populates it with data for snapshot retrieval.

```sql
CREATE TABLE mytable(a int, b int) CLUSTER BY(a+1);

INSERT INTO mytable VALUES(1,1),(3,3);
INSERT INTO mytable VALUES(2,2),(5,5);
INSERT INTO mytable VALUES(4,4);
```

--------------------------------

### RANGE BETWEEN CURRENT ROW and value FOLLOWING

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/08-window-functions/range-between.md

Example of a frame starting from the current row up to a specified interval after the current row.

```sql
RANGE BETWEEN CURRENT ROW AND INTERVAL '7' DAY FOLLOWING
```

--------------------------------

### Set Up Table and Ownership

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/guides/56-security/data-protection/index.md

Grant database creation privileges to a role, then create a table as that role. Ownership is automatically assigned.

```sql
-- Run as account_admin
GRANT CREATE DATABASE ON *.* TO ROLE data_engineer;

-- Switch to data_engineer
SET ROLE data_engineer;

CREATE DATABASE ecommerce;
CREATE TABLE ecommerce.orders (
    order_id INT,
    customer_name STRING,
    phone STRING,
    region STRING,
    amount DECIMAL(10,2),
    created_at TIMESTAMP
);

INSERT INTO ecommerce.orders VALUES
    (1, 'Alice', '13812345678', 'APAC', 299.00, '2025-01-15 10:00:00'),
    (2, 'Bob', '14987654321', 'EMEA', 150.00, '2025-01-16 11:00:00'),
    (3, 'Charlie', '13698765432', 'APAC', 520.00, '2025-01-17 09:30:00'),
    (4, 'Diana', '15012349876', 'AMER', 89.00, '2025-01-18 14:00:00');
```

--------------------------------

### RANGE BETWEEN value PRECEDING and CURRENT ROW

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/08-window-functions/range-between.md

Example of a frame starting a specified interval before the current row up to the current row.

```sql
RANGE BETWEEN INTERVAL '7' DAY PRECEDING AND CURRENT ROW
```

--------------------------------

### Get Topological Dimension of a Geometry

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/09-geospatial-functions/index.md

Use ST_DIMENSION to find the topological dimension of a geometry. For example, a point has a dimension of 0.

```sql
ST_DIMENSION(ST_MAKEGEOMPOINT(-122.35, 37.55))
```

--------------------------------

### Create Sample Users Table

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/10-sql-commands/00-ddl/01-table/70-flashback-table.md

This snippet demonstrates how to create a sample 'users' table and insert initial data for testing flashback functionality.

```sql
-- Create a sample users table
CREATE TABLE users (
    id INT,
    first_name VARCHAR,
    last_name VARCHAR,
    email VARCHAR,
    registration_date TIMESTAMP
);

-- Insert sample data
INSERT INTO users (id, first_name, last_name, email, registration_date)
VALUES (1, 'John', 'Doe', 'john.doe@example.com', '2023-01-01 00:00:00'),
       (2, 'Jane', 'Doe', 'jane.doe@example.com', '2023-01-02 00:00:00');
```

--------------------------------

### Start Flink SQL Client

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/tutorials/migrate/migrating-from-mysql-with-flink-cdc.md

Execute this command in your terminal to launch the Flink SQL Client. Ensure you are in the Flink installation directory.

```bash
./bin/sql-client.sh
```

--------------------------------

### Start CPU Profiling with pprof

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/developer/20-community/00-contributor/04-how-to-profiling.md

Use `go tool pprof` to start an HTTP server for CPU profiling. Access the profiling data via a web browser.

```bash
go tool pprof -http="0.0.0.0:8081" http://localhost:8080/debug/pprof/profile?seconds=30
```

--------------------------------

### Launch BendSQL with UI Option

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/tutorials/getting-started/connect-to-databend-bendsql.md

Starts BendSQL with a UI interface enabled, which opens a browser for interacting with Databend. Requires BendSQL to be installed.

```bash
❯ Bendsql -h 127.0.0.1 --port 8000 --ui
```

--------------------------------

### Get Start of Year from Timestamp

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/05-datetime-functions/to-start-of-year.md

Use TO_START_OF_YEAR to find the first day of the year from a timestamp. The function accepts a date or timestamp expression.

```sql
SELECT
  to_start_of_year('2023-11-12 09:38:18.165575');


```

--------------------------------

### Round Down to Start of Month

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/05-datetime-functions/to-start-of-month.md

Use TO_START_OF_MONTH to get the first day of the month from a given timestamp. Ensure the input is a valid date or timestamp.

```sql
SELECT
  to_start_of_month('2023-11-12 09:38:18.165575');

┌─────────────────────────────────────────────────┐
│ to_start_of_month('2023-11-12 09:38:18.165575') │
├─────────────────────────────────────────────────┤
│ 2023-11-01                                      │
└─────────────────────────────────────────────────┘
```

--------------------------------

### Create and Insert Sample Data

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/07-aggregate-functions/aggregate-any-value.md

Sets up a sample 'sales' table with regional sales data for demonstrating aggregate functions.

```sql
CREATE TABLE sales (
  region VARCHAR,
  manager VARCHAR,
  sales_amount DECIMAL(10, 2)
);

INSERT INTO sales VALUES
  ('North', 'Alice', 15000.00),
  ('North', 'Alice', 12000.00),
  ('South', 'Bob', 20000.00);
```

--------------------------------

### Get Current Catalog Name

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/15-context-functions/current-catalog.md

Use this function to retrieve the name of the active catalog for the current session. No specific setup or imports are required.

```sql
SELECT CURRENT_CATALOG();
```

```sql
┌───────────────────┐
│ current_catalog() │
├───────────────────┤
│ default           │
└───────────────────┘
```

--------------------------------

### Create and Show Indexes

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/10-sql-commands/50-administration-cmds/show-indexes.md

Demonstrates creating a table, an aggregating index on that table, and then displaying all created indexes. Use SHOW INDEXES to verify index creation.

```sql
CREATE TABLE t1(a int,b int);

CREATE AGGREGATING INDEX agg_idx AS SELECT avg(a), abs(sum(b)), abs(b) AS bs FROM t1 GROUP BY bs;

SHOW INDEXES;
```

--------------------------------

### Full Undrop Table Example

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/10-sql-commands/00-ddl/01-table/21-ddl-undrop-table.md

This example shows the complete process: creating a table, dropping it, viewing it in history, and then undropping it.

```sql
CREATE TABLE test(a INT, b VARCHAR);

-- drop table
DROP TABLE test;

-- show dropped tables from current database
SHOW TABLES HISTORY;

-- restore table
UNDROP TABLE test;
```

--------------------------------

### Create Example Scores Table

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/cn/sql-reference/20-sql-functions/08-window-functions/ntile.md

Sets up a sample table named 'scores' with student, subject, and score columns for demonstration purposes.

```sql
CREATE TABLE scores (
    student VARCHAR(20),
    subject VARCHAR(20),
    score INT
);

INSERT INTO scores VALUES
    ('Alice', 'Math', 95),
    ('Alice', 'English', 87),
    ('Alice', 'Science', 92),
    ('Bob', 'Math', 85),
    ('Bob', 'English', 85),
    ('Bob', 'Science', 80),
    ('Charlie', 'Math', 88),
    ('Charlie', 'English', 85),
    ('Charlie', 'Science', 85);
```

--------------------------------

### Self-hosted Databend Connection String

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/developer/00-drivers/index.md

Example of a DSN for connecting to a self-hosted Databend instance. Ensure the port and sslmode are correctly specified for your setup.

```text
databend://user:pwd@host:8000/database?sslmode=disable
```

--------------------------------

### Full Partition Window Example

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/08-window-functions/rows-between.md

Calculates the maximum and minimum amount within each product partition, considering all rows in the partition.

```sql
SELECT sale_date, product, amount,
       MAX(amount) OVER (
           PARTITION BY product 
           ORDER BY sale_date 
           ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING
       ) AS max_in_partition,
       MIN(amount) OVER (
           PARTITION BY product 
           ORDER BY sale_date 
           ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING
       ) AS min_in_partition
FROM sales
ORDER BY product, sale_date;
```

--------------------------------

### Truncate Date to Month and Week

Source: https://github.com/databendlabs/databend-docs/blob/main/docs/en/sql-reference/20-sql-functions/05-datetime-functions/date-trunc.md

Example of truncating a date to the beginning of the month and the beginning of the week. The week start is based on the default setting (Monday).

```sql
SELECT
    DATE_TRUNC(MONTH, to_date('2022-07-07')),
    DATE_TRUNC(WEEK, to_date('2022-07-07'))
```