### Install SQLCommenter Go Package

Source: https://google.github.io/sqlcommenter/go/database_sql

Use go get to install the SQLCommenter database/sql package.

```bash
go get -u github.com/google/sqlcommenter/go/database/sql

```

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

### Install Gorilla Mux SQLCommenter Middleware

Source: https://google.github.io/sqlcommenter/tags/gorrila

Install the library using go get. This command fetches the latest version of the middleware.

```bash
go get -u github.com/google/sqlcommenter/go/gorrila/mux
```

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

### Install Go Gorilla Mux SQLCommenter

Source: https://google.github.io/sqlcommenter/go/gorrila_mux

Install the SQLCommenter middleware for Gorilla Mux using go get.

```go
go get -u github.com/google/sqlcommenter/go/gorrila/mux

```

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

### Install Go HTTP Tags Package

Source: https://google.github.io/sqlcommenter/go/net_http

Install the SQLCommenter Go HTTP tags package using go get.

```bash
go get -u github.com/google/sqlcommenter/go/net/http

```

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

### Install google-cloud-sqlcommenter from source

Source: https://google.github.io/sqlcommenter/python/django

Clone the SQLCommenter repository and install from source.

```bash
git clone https://github.com/google/sqlcommenter.git
cd python/sqlcommenter-python && python3 setup.py install
```

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

### Start Rails Server

Source: https://google.github.io/sqlcommenter/ruby/rails

Start the Rails development server to observe the SQL comments in the logs.

```bash
bin/rails s

```

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

### Node.js Application Start

Source: https://google.github.io/sqlcommenter/node/sequelize

Starts a Node.js application server listening on a specified port.

```javascript
app.listen(port, () => console.log(`Application listening on ${port}`));
```

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

### Install sqlcommenter-nodejs Package

Source: https://google.github.io/sqlcommenter/node

Install a specific sqlcommenter-nodejs package (e.g., knex) from the cloned repository using npm. Replace `<path/to/package>` with the actual path to the package directory.

```bash
npm install /path/to/sqlcommenter-nodejs/packages/knex
```

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

### Verify SQLCommenter Java Installation

Source: https://google.github.io/sqlcommenter/java

After installation, check for the expected directory structure in your local Maven repository. This confirms the build artifacts are correctly placed.

```bash
~/.m2/repository/io
└── com
    └── google
        └── cloud
            └── sqlcommenter
                ├── 0.0.1
                │   ├── sqlcommenter-java-0.0.1-javadoc.jar
                │   ├── sqlcommenter-java-0.0.1-javadoc.jar.asc
                │   ├── sqlcommenter-java-0.0.1-sources.jar
                │   ├── sqlcommenter-java-0.0.1-sources.jar.asc
                │   ├── sqlcommenter-java-0.0.1.jar
                │   ├── sqlcommenter-java-0.0.1.jar.asc
                │   └── sqlcommenter-java-0.0.1.pom
                └── maven-metadata-local.xml
```

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

### Install google-cloud-sqlcommenter using pip

Source: https://google.github.io/sqlcommenter/python/django

Install the SQLCommenter package using pip for Django projects.

```bash
pip3 install google-cloud-sqlcommenter
```

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

### Install SQLCommenter for Knex.js

Source: https://google.github.io/sqlcommenter/node/knex

Add the SQLCommenter Knex.js package as a dependency to your project's package.json file and run npm install.

```json
{
    "@google-cloud/sqlcommenter-knex": "*"
}
```

```bash
npm install @google-cloud/sqlcommenter-knex --save
```

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

### Example SQL Commenter Output

Source: https://google.github.io/sqlcommenter/spec

This is an example of a SQL statement augmented with a comment containing serialized key-value pairs.

```sql
SELECT * FROM FOO /*action='%2Fparam*d',controller='index,'framework='spring',
traceparent='00-5bd66ef5095369c7b0d1f8f4bd33716a-c532cb4098ac3dd2-01',
tracestate='congo%3Dt61rcWkgMzE%2Crojo%3D00f067aa0ba902b7'*/


```

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

### Run Laravel Development Server

Source: https://google.github.io/sqlcommenter/php/laravel

Start the Laravel development server from the command line to serve your application.

```bash
php artisan serve
```

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

### Verify sqlcommenter-nodejs Installation

Source: https://google.github.io/sqlcommenter/node

Verify the installation of a specific sqlcommenter-nodejs package by running `npm list <package-name>`. This command shows details of the installed package and its location.

```bash
npm list @google-cloud/sqlcommenter-knex
```

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

### Build SQLCommenter Java from Source

Source: https://google.github.io/sqlcommenter/java

Run this command in the `java/sqlcommenter-java` directory to build the project from source. Ensure you have Gradle installed.

```bash
$ ./gradlew install
```

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

### Key-Value Pair Serialization Example

Source: https://google.github.io/sqlcommenter/spec

Demonstrates the final serialization of a key-value pair.

```markdown
key value pair | serialized_key | serialized_value | Final  
---|---|---|---
`route=/polls 1000` | `route` | `'%2Fpolls%201000'` | `route='%2Fpolls%201000'`  
`name='DROP TABLE FOO'` | `route` | `'%2Fpolls%201000'` | `route='%2Fpolls%201000'`  
`name''="DROP TABLE USERS'"` | name='' | DROP%20TABLE%20USERS' | name=''=‘DROP%20TABLE%20USERS'’  

```

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

### Run Django Development Server

Source: https://google.github.io/sqlcommenter/python/django

Command to start the Django development server from the command line.

```bash
python manage.py runserver
```

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

### Value Serialization Example Table

Source: https://google.github.io/sqlcommenter/spec

Illustrates the value serialization process with different inputs.

```markdown
value | url_encode(value) | sql_escape_with_single_quotes  
---|---|---
`DROP TABLE FOO` | `DROP%20TABLE%20FOO` | `'DROP%20TABLE%20FOO'`  
`/param first` | `%2Fparam%20first` | `'%2Fparam%20first'`  
`1234` | `1234` | `'1234'`  

```

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

### Install SQLCommenter Laravel via Composer with Local Path

Source: https://google.github.io/sqlcommenter/php/laravel

Install the SQLCommenter Laravel package using Composer after configuring a local path repository.

```bash
composer require "google/sqlcommenter-laravel"
```

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

### Basic Gorilla Mux Setup with SQLCommenter

Source: https://google.github.io/sqlcommenter/go/gorrila_mux

Use SQLCommenterMiddleware with a Gorilla Mux router to add SQLCommenter tags to requests. Ensure the router is used for handling HTTP requests.

```go
import (
    "net/http"

    sqlcommentermux "github.com/google/sqlcommenter/go/gorrila/mux"
    "github.com/gorilla/mux"
)

func runApp() {
    r := mux.NewRouter()
    r.Use(sqlcommentermux.SQLCommenterMiddleware)

    r.HandleFunc("/", ActionHome).Methods("GET")

    http.ListenAndServe(":8081", r)
}

```

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

### Install SQLCommenter for Sequelize

Source: https://google.github.io/sqlcommenter/node/sequelize

Add the SQLCommenter Sequelize package as a dependency to your project's package.json file and run npm install.

```json
{
    "@google-cloud/sqlcommenter-sequelize": "*"
}
```

```bash
npm install @google-cloud/sqlcommenter-sequelize --save
```

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

### Psycopg2 Example Output

Source: https://google.github.io/sqlcommenter/python/psycopg2

Demonstrates the typical output when running a psycopg2 script with SQL Commenter enabled, showing fetched data.

```python
python3 main.py
(1, 'Wassup?', datetime.datetime(2019, 5, 30, 13, 51, 12, 910545, tzinfo=psycopg2.tz.FixedOffsetTimezone(offset=-420, name=None)))
(2, 'Wassup?', datetime.datetime(2019, 5, 30, 13, 57, 45, 905771, tzinfo=psycopg2.tz.FixedOffsetTimezone(offset=-420, name=None)))
(3, 'Wassup?', datetime.datetime(2019, 5, 30, 13, 57, 46, 908185, tzinfo=psycopg2.tz.FixedOffsetTimezone(offset=-420, name=None)))
(4, 'Wassup?', datetime.datetime(2019, 5, 30, 13, 57, 47, 557196, tzinfo=psycopg2.tz.FixedOffsetTimezone(offset=-420, name=None)))
(5, 'Wassup?', datetime.datetime(2019, 5, 30, 13, 57, 47, 853424, tzinfo=psycopg2.tz.FixedOffsetTimezone(offset=-420, name=None)))


```

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

### Run Node.js Application

Source: https://google.github.io/sqlcommenter/node/knex

Execute the Node.js application using the `node` command. This will start the server and log a message indicating the application is listening on the specified port.

```bash
$ node app.js 
Application listening on 3000

```

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

### GET /posts SQL Query with Comments

Source: https://google.github.io/sqlcommenter/ruby/rails

Example of a SQL query generated by `GET /posts` endpoint, including `sqlcommenter_rails` fields.

```sql
Post Load (0.1ms)  SELECT "posts".* FROM "posts" /*
action='index',application='SqlcommenterRailsDemo',controller='posts',
db_driver='ActiveRecord::ConnectionAdapters::SQLite3Adapter',
framework='rails_v6.0.0.rc1',route='/posts',
traceparent='00-ff19308b1f17fedc5864e929bed1f44e-6ddace73a9debf63-01'*/


```

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

### Example SQL Statements with Comments

Source: https://google.github.io/sqlcommenter/java/hibernate

These are example SQL statements generated during the unit test execution. They show how SQL Commenter appends contextual information like action, controller, and framework to the SQL queries.

```sql
select tag0_.id as id1_2_, tag0_.name as name2_2_ from tag tag0_ where tag0_.name in (? , ?) /*action='CreatePost',controller='ForumController',framework='spring'*/
```

```sql
call next value for hibernate_sequence /*action='CreatePost',controller='ForumController',framework='spring'*/
```

```sql
insert into post (title, id) values (?, ?) /*action='CreatePost',controller='ForumController',framework='spring'*/
```

```sql
insert into post_tag (post_id, tag_id) values (?, ?) /*action='CreatePost',controller='ForumController',framework='spring'*/
```

```sql
insert into post_tag (post_id, tag_id) values (?, ?) /*action='CreatePost',controller='ForumController',framework='spring'*/
```

```sql
select post0_.id as id1_0_, post0_.title as title2_0_ from post post0_ where post0_.title=? /*action='FindPostsByTitle',controller='ForumController',framework='spring'*/
```

```sql
select post0_.id as id1_0_0_, post0_.title as title2_0_0_ from post post0_ where post0_.id=? /*action='FindPostById',controller='ForumController',framework='spring'*/
```

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

### Default Django urls.py for SQLCommenter

Source: https://google.github.io/sqlcommenter/python/django

Example urls.py configuration for a Django app.

```python
# polls/urls.py

from django.urls import path
from . import views

urlpatterns = [
    path('', views.index, name='index'),
]

```

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

### Gorilla Mux Setup with SQLCommenter and OpenTelemetry

Source: https://google.github.io/sqlcommenter/go/gorrila_mux

Integrate SQLCommenterMiddleware with otelmux.Middleware for Gorilla Mux to include OpenTelemetry traceparent information in SQL comments. This requires setting up an OpenTelemetry tracer provider.

```go
import (
    "context"
    "log"
    "net/http"

    sqlcommentermux "github.com/google/sqlcommenter/go/gorrila/mux"
    "github.com/gorilla/mux"
    "go.opentelemetry.io/contrib/instrumentation/github.com/gorilla/mux/otelmux"
    "go.opentelemetry.io/otel"
    stdout "go.opentelemetry.io/otel/exporters/stdout/stdouttrace"
    "go.opentelemetry.io/otel/propagation"
    sdktrace "go.opentelemetry.io/otel/sdk/trace"
)

func main() {
    tp, err := initTracer()
    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        if err := tp.Shutdown(context.Background()); err != nil {
            log.Printf("Error shutting down tracer provider: %v", err)
        }
    }()

    r := mux.NewRouter()
    r.Use(otelmux.Middleware("sqlcommenter sample-server"), sqlcommentermux.SQLCommenterMiddleware)

    r.HandleFunc("/", ActionHome).Methods("GET")

    http.ListenAndServe(":8081", r)
}

func initTracer() (*sdktrace.TracerProvider, error) {
    exporter, err := stdout.New(stdout.WithPrettyPrint())
    if err != nil {
        return nil, err
    }
    tp := sdktrace.NewTracerProvider(
        sdktrace.WithSampler(sdktrace.AlwaysSample()),
        sdktrace.WithBatcher(exporter),
    )
    otel.SetTracerProvider(tp)
    otel.SetTextMapPropagator(propagation.NewCompositeTextMapPropagator(propagation.TraceContext{}, propagation.Baggage{}))
    return tp, nil
}

```

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

### Configure Composer for Local Path Installation

Source: https://google.github.io/sqlcommenter/php/laravel

Add a local path repository to your composer.json file to install the SQLCommenter Laravel package from a cloned source.

```json
# Add the following to composer.json 

"repositories": [
{
"type": "path",
"url": "/full/or/relative/path/to/sqlcommenter/php/sqlcommenter-php/packages/sqlcommenter-laravel/"
}
]
```

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

### Default Django views.py for SQLCommenter

Source: https://google.github.io/sqlcommenter/python/django

Example views.py for a Django app to demonstrate SQLCommenter integration.

```python
# polls/views.py

from django.http import HttpResponse
from .models import Question

def index(request):
    count = Question.objects.count()
    return HttpResponse(f"There are {count} questions in the DB.\n")

```

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

### End-to-End Example with psycopg2

Source: https://google.github.io/sqlcommenter/python/flask

Demonstrates a full Flask application using psycopg2 with SQLCommenter. It sets up a database connection with a custom cursor factory and runs a Flask app that queries a database. The database logs will show SQL statements augmented with comments.

```python
#!/usr/bin/env python3

import psycopg2
import json
import flask
app = flask.Flask(__name__)

from google.cloud.sqlcommenter import FlaskMiddleware
from google.cloud.sqlcommenter.psycopg2.extension import CommenterCursorFactory

conn = None

@app.route('/polls')
def get_polls():
    cursor = conn.cursor()
    cursor.execute("SELECT * FROM polls_question")
    str_polls = list(map(lambda s: str(s), cursor))

    cursor.close()
    return json.dumps(str_polls)

def main():
    global conn

    try:
        conn = psycopg2.connect(user='', password='$postgres$',
                host='127.0.0.1', port='5432', database='quickstart_py',
                cursor_factory=CommenterCursorFactory())

        # Now enable the middleware.
        FlaskMiddleware(app)

        # Finally run the Flask web app.
        app.run(host='localhost', port=8088, threaded=True)
    except Exception as e:
        print('Encountered exception %s'%(e))

    finally:
        if conn:
            conn.close()


if __name__ == '__main__':
    main()
```

```sql
SELECT * FROM polls_question
/*controller='get_polls',db_driver='psycopg2',framework='sqlalchemy%3A1.3.4',
route='/polls',traceparent='00-5b3df77064f35f091e89fb40022e2a1d-9bbd4868cf0ba2c3-01'*/
```

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

### Define Django URL Patterns

Source: https://google.github.io/sqlcommenter/python/django

Set up basic URL routing for a Django app. This example shows how to map the root URL to the index view.

```python
from django.urls import path
from . import views

urlpatterns = [
    path('', views.index, name='index'),
]
```

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

### Example PostgreSQL Log Output with SQL Statements

Source: https://google.github.io/sqlcommenter/databases/postgresql

This is an example of the log output generated by a PostgreSQL server configured for detailed logging. It shows connection information and executed SQL statements, including those with SQL Commenter tags.

```log
2019-05-31 16:27:27.482 PDT [19175] LOG:  listening on IPv4 address "127.0.0.1", port 5432
2019-05-31 16:27:27.482 PDT [19175] LOG:  listening on IPv6 address "::1", port 5432
2019-05-31 16:27:27.482 PDT [19175] LOG:  listening on Unix socket "/tmp/.s.PGSQL.5432"
2019-05-31 16:27:27.503 PDT [19176] LOG:  database system was shut down at 2019-05-31 16:27:06 PDT
2019-05-31 16:27:27.508 PDT [19175] LOG:  database system is ready to accept connections
2019-05-31 16:27:31.190 PDT [19183] LOG:  statement: SET TIME ZONE 'UTC'
2019-05-31 16:27:31.195 PDT [19183] LOG:  statement: INSERT INTO "polls_question"
("question_text", "pub_date") VALUES ('Wassup?', '2019-05-31T23:27:31.175952+00:00'::timestamptz)
RETURNING "polls_question"."id" /*controller='index',db_driver='django.db.backends.postgresql',
framework='django%3A2.2.1',route='%5Epolls/%24'*/

```

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

### Postgresql Log with DB Framework Info

Source: https://google.github.io/sqlcommenter/python/sqlalchemy

Example of a Postgresql server log showing a SQL statement with database framework information appended by SQLCommenter.

```sql
2019-07-18 14:11:19.576 -03 [30108] LOG:  statement: SELECT * FROM polls_question
/*db_framework='sqlalchemy%3A1.3.5'*/
```

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

### Postgresql Log with DB Driver Info

Source: https://google.github.io/sqlcommenter/python/sqlalchemy

Example of a Postgresql server log showing a SQL statement with database driver information appended by SQLCommenter.

```sql
2019-07-18 14:03:33.426 -03 [29858] LOG:  statement: SELECT * FROM polls_question
/*db_driver='psycopg2'*/
```

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

### Run PostgreSQL Server with Custom Data Directory

Source: https://google.github.io/sqlcommenter/databases/postgresql

Start the PostgreSQL server using the `postgres` command, specifying the `PGDATA` environment variable to use a custom data directory. This is often done after modifying configuration files.

```bash
$ PGDATA=/usr/local/var/postgres postgres

```

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

### Postgresql Log with OpenCensus Trace

Source: https://google.github.io/sqlcommenter/python/sqlalchemy

Example of a Postgresql server log showing a SQL statement with OpenCensus trace information appended by SQLCommenter.

```sql
2019-07-18 14:10:15.228 -03 [30071] LOG:  statement: SELECT * FROM polls_question
/*traceparent='00-bf66750ad4c76f614c0a99d843758cbb-e6b27c3caf35de73-01'*/
```

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

### All SQL Commenter Fields in SQL Comments

Source: https://google.github.io/sqlcommenter/node/sequelize

A comprehensive example showing all available SQL Commenter fields, including traceparent, tracestate, route, client_timezone, and db_driver.

```sql
2019-06-03 14:32:10.842 PDT [32004] LOG:  statement: SELECT * from polls_question 
/*client_timezone:'%2B00%3A00',db_driver='sequelize%3A0.0.1',route='%5E%2Fpolls%2F%1000',traceparent='00-11000000000000ff-020000ee-01',tracestate='brazzaville=t61rcWkgMzE,rondo=00f067aa0ba902b7'*/
```

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

### PostgreSQL Log with Controller and Framework Comments

Source: https://google.github.io/sqlcommenter/python/django

Example of a PostgreSQL log statement showing SQL comments added by SQL Commenter, including controller and framework information.

```sql
2019-07-19 14:27:51.370 -03 [41382] LOG:  statement: SELECT COUNT(*) AS "__count" FROM "polls_question"
/*controller='index',framework='django%3A2.2.3',route='polls/'*/
```

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

### SQLAlchemy Query Output

Source: https://google.github.io/sqlcommenter/python/sqlalchemy

Example output from a SQLAlchemy query executed with SQLCommenter.

```text
python3 main.py
(1, 'Wassup?', datetime.datetime(2019, 5, 30, 13, 51, 12, 910545, tzinfo=psycopg2.tz.FixedOffsetTimezone(offset=-420, name=None)))
(2, 'Wassup?', datetime.datetime(2019, 5, 30, 13, 57, 45, 905771, tzinfo=psycopg2.tz.FixedOffsetTimezone(offset=-420, name=None)))
(3, 'Wassup?', datetime.datetime(2019, 5, 30, 13, 57, 46, 908185, tzinfo=psycopg2.tz.FixedOffsetTimezone(offset=-420, name=None)))
(4, 'Wassup?', datetime.datetime(2019, 5, 30, 13, 57, 47, 557196, tzinfo=psycopg2.tz.FixedOffsetTimezone(offset=-420, name=None)))
(5, 'Wassup?', datetime.datetime(2019, 5, 30, 13, 57, 47, 853424, tzinfo=psycopg2.tz.FixedOffsetTimezone(offset=-420, name=None)))
```

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

### Node.js Sequelize with All Options Set

Source: https://google.github.io/sqlcommenter/node/sequelize

Demonstrates a comprehensive SQLCommenter configuration for Node.js Sequelize applications, enabling client timezone, database driver, route, traceparent, and tracestate information in SQL comments. This setup provides maximum observability.

```javascript
// In file app.js.
const { NodeTracerProvider } = require("@opentelemetry/node");
const { BatchSpanProcessor } = require("@opentelemetry/tracing");
const {
  TraceExporter,
} = require("@google-cloud/opentelemetry-cloud-trace-exporter");

const tracerProvider = new NodeTracerProvider();
// Export to Google Cloud Trace
tracerProvider.addSpanProcessor(
  new BatchSpanProcessor(new TraceExporter({ logger }), {
    bufferSize: 500,
    bufferTimeout: 5 * 1000,
  })
);
tracerProvider.register();

// OpenTelemetry initialization should happen before importing any libraries
// that it instruments
const { Sequelize } = require("sequelize");
const {
  wrapSequelizeAsMiddleware,
} = require("@google-cloud/sqlcommenter-sequelize");

const sequelize = new Sequelize("postgres://user:pass@example.com:5432/dbname");

const express = require("express");
const app = express();
const port = process.env.APP_PORT || 3000;

// SQLCommenter express middleware injects the route into the traces
app.use(
  wrapSequelizeAsMiddleware(
    sequelize,
    {
      client_timezone: true,
      db_driver: true,
      route: true,
      traceparent: true,
      tracestate: true,
    },
    { TraceProvider: "OpenTelemetry" }
  )
);

app.get("/", (req, res) => res.send("Hello, sqlcommenter-nodejs!!"));
app.get("^/polls/:param", function (req, res) {
  sequelize

```

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

### Install SQLCommenter Laravel via Composer

Source: https://google.github.io/sqlcommenter/php/laravel

Use Composer to add the SQLCommenter Laravel package to your project dependencies.

```bash
composer require google/sqlcommenter-laravel
```

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

### End-to-End Example with SQLAlchemy

Source: https://google.github.io/sqlcommenter/python/flask

Illustrates a Flask application using SQLAlchemy with SQLCommenter. It configures SQLAlchemy's create_engine and registers an event listener for before cursor execution. Visiting a route triggers a query, and database logs will show the query with added comments.

```python
#!/usr/bin/env python3

import json
import flask
app = flask.Flask(__name__)

from sqlalchemy import create_engine, event
from sqlcommenter import FlaskMiddleware
from sqlcommenter.sqlalchemy.executor import BeforeExecuteFactory

engine = None

@app.route('/polls')
def get_polls():
    result_proxy = engine.execute("SELECT * FROM polls_question")
    str_polls = list(map(lambda s: str(s), result_proxy))

    result_proxy.close()
    return json.dumps(str_polls)

def main():
    global engine
    engine = create_engine("postgresql://:$postgres$@127.0.0.1:5432/quickstart_py")
    event.listen(engine, 'before_cursor_execute', BeforeExecuteFactory(), retval=True)

    FlaskMiddleware(app)
    app.run(host='localhost', port=8089, threaded=True)

if __name__ == '__main__':
    main()
```

```sql
SELECT * FROM polls_question
/*controller='get_polls',db_driver='psycopg2%3A2.8.2%20%28dt%20dec%20pq3%20ext%20lo64%29',
dbapi_level='2.0',dbapi_threadsafety=2,driver_paramstyle='pyformat',
framework='flask%3A1.0.3',libpq_version=100001,route='/polls'*/
```

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

### Django urls.py to include App Name in SQLCommenter

Source: https://google.github.io/sqlcommenter/python/django

Example urls.py configuration for a Django app when including app name in SQLCommenter.

```python
# polls/urls.py

from django.urls import path
from . import apps, views

app_name = apps.PollsConfig.name

urlpatterns = [
    path('', views.index, name='index'),
]

```

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

### Knex Integration with Route Tracing

Source: https://google.github.io/sqlcommenter/node/knex

Integrate Knex.js with SQLCommenter to include route information in traces. This setup is suitable for Express.js applications.

```javascript
// In file app.js.
const Knex = require('knex'); // Knex to be wrapped say v0.0.1
const {wrapMainKnexAsMiddleware} = require('@google-cloud/sqlcommenter-knex');
const express = require('express');

const options = {
    client: 'postgresql',
    connection: {
        host: '127.0.0.1',
        password: '$postgres$',
        database: 'quickstart_nodejs'
    }
};
const knex = Knex(options); // knex instance

const app = express();
const port = process.env.APP_PORT || 3000;

// Use the knex+express middleware with route
app.use(wrapMainKnexAsMiddleware(Knex, {route: true}));

app.get('/', (req, res) => res.send('Hello, sqlcommenter-nodejs!!'));
app.get('^/polls/:param', function(req, res) {
    knex.raw('SELECT * from polls_question').then(function(polls) {
        const blob = JSON.stringify(polls);
        res.send(blob);
    }).catch(function(err) {
        console.log(err);
        res.send(500);
    });
});
app.listen(port, () => console.log(`Application listening on ${port}`));


```

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

### Prepare SQLCommenter Tags from HTTP Request (Go)

Source: https://google.github.io/sqlcommenter/tags/go

Use this low-level package to prepare SQLCommenterTags from an HTTP request. The core package can then be used to inject these tags into a context.

```go
import (
 sqlcommenterhttp "github.com/google/sqlcommenter/go/net/http"
 core "github.com/google/sqlcommenter/go/core"
)

requestTags := sqlcommenterhttp.NewHTTPRequestTags(framework string, route string, action string)
ctx := core.ContextInject(request.Context(), requestTags)
requestWithTags := request.WithContext(ctx)
```

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

### Prepare and Inject HTTP Request Tags

Source: https://google.github.io/sqlcommenter/tags/context

Use this to create SQLCommenterTags from an HTTP request and inject them into the request context. Ensure the core package is imported for context injection.

```go
import (
	sqlcommenterhttp "github.com/google/sqlcommenter/go/net/http"
	"github.com/google/sqlcommenter/go/core"
)

requestTags := sqlcommenterhttp.NewHTTPRequestTags(framework string, route string, action string)
ctx := core.ContextInject(request.Context(), requestTags)
requestWithTags := request.WithContext(ctx)
```

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

### SQL Query with All Options Set

Source: https://google.github.io/sqlcommenter/node/knex

This log demonstrates a SQL query with all available SQL Commenter options enabled: db_driver, route, traceparent, and tracestate. This provides comprehensive context for the query.

```sql
2019-06-03 14:32:10.842 PDT [32004] LOG:  statement: SELECT * from polls_question 
/*db_driver='knex%3A0.0.1',route='%5E%2Fpolls%2F%1000',traceparent='00-11000000000000ff-020000ee-01',tracestate='brazzaville=t61rcWkgMzE,rondo=00f067aa0ba902b7'*/
```

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

### PostgreSQL Log with Traceparent Comment

Source: https://google.github.io/sqlcommenter/python/django

Example of a PostgreSQL log statement with a traceparent comment, typically used for distributed tracing.

```sql
2019-07-19 17:39:27.430 -03 [46170] LOG:  statement: SELECT COUNT(*) AS "__count" FROM "polls_question"
/*traceparent='00-fd720cffceba94bbf75940ff3caaf3cc-4fd1a2bdacf56388-01'*/
```

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

### Implement Posts Controller Actions

Source: https://google.github.io/sqlcommenter/ruby/rails

Define the `index` and `create` actions for the `PostsController` to handle fetching and creating posts.

```ruby
# app/controllers/posts_controller.rb
class PostsController < ApplicationController
  def index
    render json: Post.all
  end

  def create
    title = params[:title].to_s.strip
    head :bad_request if title.empty?
    render json: Post.create!(title: title)
  end
end

```

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

### POST /posts SQL Query with Comments

Source: https://google.github.io/sqlcommenter/ruby/rails

Example of a SQL query generated by `POST /posts` endpoint, including `sqlcommenter_rails` fields.

```sql
Post Create (0.2ms)  INSERT INTO "posts" ("title", "created_at", "updated_at")
VALUES (?, ?, ?) /*action='create',application='SqlcommenterRailsDemo',
controller='posts',db_driver='ActiveRecord::ConnectionAdapters::SQLite3Adapter',
framework='rails_v6.0.0.rc1',route='/posts',
traceparent='00-ff19308b1f17fedc5864e929bed1f44e-6ddace73a9debf63-01'*/

```

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

### PostgreSQL Log with DB Driver Comment

Source: https://google.github.io/sqlcommenter/python/django

Example of a PostgreSQL log statement with a db_driver comment, indicating the database backend used by the application.

```sql
2019-07-19 14:47:53.066 -03 [41602] LOG:  statement: SELECT COUNT(*) AS "__count" FROM "polls_question"
/*db_driver='django.db.backends.postgresql'*/
```

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

### PostgreSQL Log with App Name Comment

Source: https://google.github.io/sqlcommenter/python/django

Example of a PostgreSQL log statement showing an app_name comment, useful for identifying the application generating the query.

```sql
2019-07-19 15:31:33.681 -03 [42962] LOG:  statement: SELECT COUNT(*) AS "__count" FROM "polls_question"
/*app_name='polls'*/
```

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

### Configure SQLCommenter with All Fields

Source: https://google.github.io/sqlcommenter/node/knex

Manually set all available fields (db_driver, route, traceparent, tracestate) and specify OpenTelemetry as the trace provider for comprehensive SQL comments.

```javascript
// Manually set all the variables.
wrapMainKnexAsMiddleware(
    Knex,
    include={
        db_driver: true,
        route: true,
        traceparent: true,
        tracestate: true,
    },
    options={ TraceProvider: 'OpenTelemetry' }
);
```

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

### psycopg2 Log with libpq Version

Source: https://google.github.io/sqlcommenter/python/psycopg2

Demonstrates a PostgreSQL server log entry for a SQL statement including the libpq version comment added by SQL Commenter.

```sql
2019-07-17 16:05:37.618 -03 [16708] LOG:  statement: SELECT * FROM polls_question
/*libpq_version=110002*/
```

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

### Configure Hibernate Transaction Template

Source: https://google.github.io/sqlcommenter/java/hibernate

Sets up a TransactionTemplate for Hibernate, requiring a SessionFactory and a transaction manager. This is a common setup for managing transactions in Spring applications using Hibernate.

```java
public TransactionTemplate transactionTemplate(SessionFactory sessionFactory) {
        return new TransactionTemplate(transactionManager(sessionFactory));
    }
```

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

### Prepare and Inject SQLCommenter Tags

Source: https://google.github.io/sqlcommenter/go/net_http

Use the http-tags package to create SQLCommenterTags from an HTTP request and inject them into the request context. This is useful for instrumenting various frameworks.

```go
import (
    sqlcommenterhttp "github.com/google/sqlcommenter/go/net/http"
    "github.com/google/sqlcommenter/go/core"
)

requestTags := sqlcommenterhttp.NewHTTPRequestTags(framework string, route string, action string)
ctx := core.ContextInject(request.Context(), requestTags)
requestWithTags := request.WithContext(ctx)

```

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

### Make HTTP Request with curl

Source: https://google.github.io/sqlcommenter/python/django

Use curl to send an HTTP GET request to the Django development server. This action will generate a SQL query that SQL Commenter can annotate.

```bash
curl http://127.0.0.1:8000/polls/
```

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

### Knex Integration with OpenTelemetry and All Options

Source: https://google.github.io/sqlcommenter/node/knex

Configure Knex.js with OpenTelemetry and SQLCommenter, enabling traceparent, tracestate, and db_driver. Ensure OpenTelemetry initialization precedes library imports.

```javascript
// In file app.js.
const { NodeTracerProvider } = require("@opentelemetry/node");
const { BatchSpanProcessor } = require("@opentelemetry/tracing");
const {
  TraceExporter,
} = require("@google-cloud/opentelemetry-cloud-trace-exporter");

const tracerProvider = new NodeTracerProvider();
// Export to Google Cloud Trace
tracerProvider.addSpanProcessor(
  new BatchSpanProcessor(new TraceExporter({ logger }), {
    bufferSize: 500,
    bufferTimeout: 5 * 1000,
  })
);
tracerProvider.register();

// OpenTelemetry initialization should happen before importing any libraries
// that it instruments
const express = require("express");
const Knex = require("knex");
const { wrapMainKnexAsMiddleware } = require("@google-cloud/sqlcommenter-knex");

const knexOptions = {
    client: 'postgresql',
    connection: {
        host: '127.0.0.1',
        password: '$postgres$',
        database: 'quickstart_nodejs'
    }
};
const knex = Knex(knexOptions); // knex instance

const app = express();
const port = process.env.APP_PORT || 3000;

// SQLCommenter express middleware injects the route into the traces
app.use(
  wrapMainKnexAsMiddleware(
    Knex,
    {
      traceparent: true,
      tracestate: true,

      // Optional
      db_driver: false,
      route: false,
    },
    { TraceProvider: "OpenTelemetry" }
  )
);

app.get('/', (req, res) => res.send('Hello, sqlcommenter-nodejs!!'));
app.get('^/polls/:param', function(req, res) {
    knex.raw('SELECT * from polls_question').then(function(polls) {
        const blob = JSON.stringify(polls);
        res.send(blob);
    }).catch(function(err) {
        console.log(err);
        res.send(500);
    });
});
app.listen(port, () => console.log(`Application listening on ${port}`));


```

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

### Node.js Sequelize with Route

Source: https://google.github.io/sqlcommenter/node/sequelize

Applies SQLCommenter middleware to an Express.js application using Sequelize, enabling the injection of route information into SQL query comments. This setup is suitable for basic route tracking.

```javascript
// In file app.js.
const Sequelize = require('sequelize');
const {wrapSequelizeAsMiddleware} = require('@google-cloud/sqlcommenter-sequelize');
const express = require('express');

// Using a connection URI
const sequelize = new Sequelize('postgres://user:pass@example.com:5432/dbname');

const app = express();
const port = process.env.APP_PORT || 3000;

// Use the sequelize+express middleware with route
app.use(wrapSequelizeAsMiddleware(sequelize, {route: true}));

app.get('/', (req, res) => res.send('Hello, sqlcommenter-nodejs!!'));
app.get('^/polls/:param', function(req, res) {
    sequelize.query('SELECT * from polls_question').then(function(polls) {
        const blob = JSON.stringify(polls);
        res.send(blob);
    }).catch(function(err) {
        console.log(err);
        res.send(500);
    });
});
app.listen(port, () => console.log(`Application listening on ${port}`));

```

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

### SQLCommenter Middleware for Gorilla Mux (Go)

Source: https://google.github.io/sqlcommenter/tags/go

This library provides a middleware that extracts SQLCommenter HTTP request tags from a request being handled by gorilla/mux and attaches them to the request’s context. This same context, when used to run queries using sqlcommenter/go/database/sql, allows request tags and traceparent(if using otelmux) to be passed into SQL comments.

```go
import (
 "net/http"
 sqlcommentermux "github.com/google/sqlcommenter/go/gorrila/mux"
 "github.com/gorilla/mux"
)

func runApp() {
 r := mux.NewRouter()
 r.Use(sqlcommentermux.SQLCommenterMiddleware)
 r.HandleFunc("/", ActionHome).Methods("GET")
 http.
```

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

### Configure Gorilla Mux with SQLCommenter Middleware

Source: https://google.github.io/sqlcommenter/tags/mux

Use the SQLCommenterMiddleware in your Gorilla Mux router to automatically process incoming requests.

```go
import (
	"net/http"
	sqlcommentermux "github.com/google/sqlcommenter/go/gorrila/mux"
	"github.com/gorilla/mux"
)

func runApp() {
	r := mux.NewRouter()
	r.Use(sqlcommentermux.SQLCommenterMiddleware)
	r.HandleFunc("/", ActionHome).Methods("GET")
	http. 
```

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

### Hibernate Test Setup with Transactional Data Initialization

Source: https://google.github.io/sqlcommenter/java/hibernate

Initializes test data within a transaction using Spring's TransactionTemplate. This ensures that the test environment is set up with necessary entities before test execution.

```java
@Before
    public void init() {
        try {
            transactionTemplate.execute((TransactionCallback<Void>) transactionStatus -> {
                Tag hibernate = new Tag();
                hibernate.setName("hibernate");
                entityManager.persist(hibernate);

                Tag jpa = new Tag();
                jpa.setName("jpa");
                entityManager.persist(jpa);

                return null;
            });
        } catch (TransactionException e) {
            fail(e.getMessage());
        }
    }
```

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

### Run SQLCommenter Java Tests

Source: https://google.github.io/sqlcommenter/java

Execute the test suite for the sqlcommenter-java project using Gradle. This command verifies the functionality of the library.

```bash
$ ./gradlew test
```

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

### psycopg2 Log with DB Driver Info

Source: https://google.github.io/sqlcommenter/python/psycopg2

Illustrates a PostgreSQL server log entry for a SQL statement including the database driver information, such as version and build details, appended by SQL Commenter.

```sql
2019-07-17 15:56:05.192 -03 [16491] LOG:  statement: SELECT * FROM polls_question
/*db_driver='psycopg2%3A2.8.3%20%28dt%20dec%20pq3%20ext%20lo64%29'*/
```

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

### Monitor Development Log for SQL Statements

Source: https://google.github.io/sqlcommenter/ruby/rails

Use `tail` and `grep` to monitor the server's development log for SQL statements generated by the application.

```bash
tail -f log/development.log | grep 'Post '

```

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

### Use Local Maven Packages

Source: https://google.github.io/sqlcommenter/java

When using Maven to build packages that depend on locally installed artifacts (like SQLCommenter Java), use this command to ensure Maven can find them. The `-nsu` flag prevents Maven from checking remote repositories for snapshots.

```bash
mvn install -nsu
```

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

### Open Database Connection with SQLCommenter

Source: https://google.github.io/sqlcommenter/go/database_sql

Use the sqlcommenter's go-sql database driver to open a connection. It's recommended to use context-based methods like QueryContext for passing information from the framework to the database driver.

```go
import (
    "database/sql"

    gosql "github.com/google/sqlcommenter/go/database/sql"
    sqlcommentercore "github.com/google/sqlcommenter/go/core"
    _ "github.com/lib/pq" // or any other database driver
)

var (
  db *sql.DB
  err error
)

db, err = gosql.Open("<driver>", "<connectionString>", sqlcommentercore.CommenterOptions{
    Config: sqlcommentercore.CommenterConfig{<flag>:bool}
    Tags  : sqlcommentercore.StaticTags{<tag>: string} // optional
})

```

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

### Forum Service Implementation

Source: https://google.github.io/sqlcommenter/java/hibernate

Implements the ForumService interface, handling post creation, retrieval, and transaction management.

```java
// In file ForumServiceImpl.java

package com.google.cloud.sqlcommenter.spring.jpa.service;

import com.google.cloud.sqlcommenter.spring.jpa.dao.PostRepository;
import com.google.cloud.sqlcommenter.spring.jpa.dao.TagRepository;
import com.google.cloud.sqlcommenter.spring.jpa.domain.Post;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.util.Arrays;
import java.util.List;

@Service
public class ForumServiceImpl implements ForumService {

    @Autowired
    private PostRepository postRepository;

    @Autowired
    private TagRepository tagRepository;

    @Override
    @Transactional
    public Post createPost(String title, String... tags) {
        Post post = new Post();
        post.setTitle(title);
        post.getTags().addAll(tagRepository.findByNameIn(Arrays.asList(tags)));
        return postRepository.save(post);
    }

    @Override
    @Transactional(readOnly = true)
    public List<Post> findPostsByTitle(String title) {
        return postRepository.findByTitle(title);
    }

    @Override
    @Transactional
    public Post findPostById(Long id) {
        return postRepository.findById(id).orElse(null);
    }
}

```

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

### SQLCommenter Drop-in Replacement for database/sql (Go)

Source: https://google.github.io/sqlcommenter/tags/go

SQLCommenter provides a drop-in replacement for Go's database/sql library. You can start using SQLCommenter’s database/sql without changing your business logic code and use one of the framework instrumentation to propagate tags and traceparent to the SQL queries.

```go
Please use the sqlcommenter’s go-sql database driver to open a connection and use that connection to execute statements. Due to inherent nature of Go, the safer way to pass information from framework to database driver is via context.
```

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

### Psycopg2 with libpq Version Information

Source: https://google.github.io/sqlcommenter/python/psycopg2

Includes libpq version information in SQL comments via SQL Commenter. Requires psycopg2. Ensure DSN is correctly configured.

```python
#!/usr/bin/env python3

import psycopg2
from google.cloud.sqlommenter.psycopg2.extension import CommenterCursorFactory

DSN = '...'  # DB connection info

def main():
    cursor_factory = CommenterCursorFactory(with_libpq_version=True)

    with psycopg2.connect(DSN, cursor_factory=cursor_factory) as conn:
        with conn.cursor() as cursor:
            cursor.execute("SELECT * FROM polls_question")
            for row in cursor:
                print(row)

if __name__ == '__main__':
    main()

```

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

### Configure Gorilla Mux with SQLCommenter Middleware

Source: https://google.github.io/sqlcommenter/tags/gorrila

Apply the SQLCommenterMiddleware to your Gorilla Mux router. This middleware intercepts incoming requests and adds SQLCommenter tags to the context.

```go
import (
	"net/http"
	sqlcommentermux "github.com/google/sqlcommenter/go/gorrila/mux"
	"github.com/gorilla/mux"
)

func runApp() {
	r := mux.NewRouter()
	r.Use(sqlcommentermux.SQLCommenterMiddleware)
	r.HandleFunc("/", ActionHome).Methods("GET")
	http.ListenAndServe(":8080", r)
}
```

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

### SQLAlchemy with OpenCensus

Source: https://google.github.io/sqlcommenter/python/sqlalchemy

Integrates SQLCommenter with OpenCensus for tracing. Ensure you have OpenCensus configured.

```python
#!/usr/bin/env python3

from sqlalchemy import create_engine, event
from google.cloud.sqlcommenter.sqlalchemy.executor import BeforeExecuteFactory

def main():
    tracer = Tracer(exporter=NoopExporter, sampler=AlwaysOnSampler())
    engine = create_engine(DB_URL)

    listener = BeforeExecuteFactory(with_opencensus=True)
    event.listen(engine, 'before_cursor_execute', listener, retval=True)

    with tracer.span():
        result = engine.execute('SELECT * FROM polls_question')
        for row in result:
            print(row)

if __name__ == '__main__':
    main()
```

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

### Wrap Knex with SQLCommenter Middleware

Source: https://google.github.io/sqlcommenter/node/knex

Configure and wrap the Knex instance with SQLCommenter middleware to automatically add tracing information to your queries. Ensure the necessary options like traceparent, tracestate, and optionally db_driver and route are provided, along with the TraceProvider.

```javascript
const wrapMainKnexAsMiddleware = require("@sqlcommenter/knex");

const knex = require('knex')({
  client: 'pg',
  connection: {
    host : '127.0.0.1',
    user : 'root',
    password : ''
  }
});

app.use(
  wrapMainKnexAsMiddleware(
    knex,
    {
      traceparent: true,
      tracestate: true,

      // Optional
      db_driver: true,
      route: true,
    },
    { TraceProvider: "OpenTelemetry" }
  )
);

app.get('/', (req, res) => res.send('Hello, sqlcommenter-nodejs!!'));
app.get('^/polls/:param', function(req, res) {
    knex.raw('SELECT * from polls_question').then(function(polls) {
        const blob = JSON.stringify(polls);
        res.send(blob);
    }).catch(function(err) {
        console.log(err);
        res.send(500);
    });
});
app.listen(port, () => console.log(`Application listening on ${port}`));
```

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

### Django settings.py with OpenCensus and SQLCommenter

Source: https://google.github.io/sqlcommenter/python/django

Configure Django settings for both OpenCensus and SQLCommenter, disabling default fields.

```python
# settings.py
INSTALLED_APPS = [
    'opencensus.ext.django',
    ...
]


MIDDLEWARE = [
    'opencensus.ext.django.middleware.OpencensusMiddleware',
    'sqlcommenter.django.middleware.SqlCommenter',
    ...
]

OPENCENSUS = {
    'TRACE': {
        'SAMPLER': 'opencensus.trace.samplers.AlwaysOnSampler()',
    }
}

SQLCOMMENTER_WITH_CONTROLLER = False
SQLCOMMENTER_WITH_FRAMEWORK = False
SQLCOMMENTER_WITH_ROUTE = False
SQLCOMMENTER_WITH_OPENCENSUS = True

```