### Install Micrate using Homebrew

Source: https://github.com/amberframework/micrate/blob/master/README.md

Install the standalone binary tool for Micrate using Homebrew by tapping the repository and installing the package.

```bash
$ brew tap amberframework/micrate
$ brew install micrate
```

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

### Example SQL Migration with Create and Drop Table

Source: https://github.com/amberframework/micrate/blob/master/README.md

An example SQL migration demonstrating how to create a 'users' table in the 'Up' section and drop it in the 'Down' section.

```sql
-- +micrate Up
CREATE TABLE users(id INT PRIMARY KEY, email VARCHAR NOT NULL);

-- +micrate Down
DROP TABLE users;
```

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

### SQL Migration with Statement Delimiters

Source: https://github.com/amberframework/micrate/blob/master/README.md

Example of a complex SQL migration using '+micrate StatementBegin' and '+micrate StatementEnd' to handle multi-statement scripts, such as creating a partitioned table function.

```sql
-- +micrate Up
-- +micrate StatementBegin
CREATE OR REPLACE FUNCTION histories_partition_creation( DATE, DATE )
returns void AS $$
DECLARE
  create_query text;
BEGIN
  FOR create_query IN SELECT
      'CREATE TABLE IF NOT EXISTS histories_'
      || TO_CHAR( d, 'YYYY_MM' )
      || ' ( CHECK( created_at >= timestamp '''
      || TO_CHAR( d, 'YYYY-MM-DD 00:00:00' )
      || ''' AND created_at < timestamp '''
      || TO_CHAR( d + INTERVAL '1 month', 'YYYY-MM-DD 00:00:00' )
      || ''' ) ) inherits ( histories );'
    FROM generate_series( $1, $2, '1 month' ) AS d
  LOOP
    EXECUTE create_query;
  END LOOP;  -- LOOP END
END;         -- FUNCTION END
$$
language plpgsql;
-- +micrate StatementEnd
```

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

### Apply Pending Migrations

Source: https://github.com/amberframework/micrate/blob/master/README.md

Command to apply all pending database migrations using Micrate. Shows example output indicating successful migration.

```bash
$ micrate up
Migrating db, current version: 0, target: 20160524162947
OK   20160524162446_add_users_table.sql
```

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

### Crystal Runner Script for Micrate CLI

Source: https://github.com/amberframework/micrate/blob/master/README.md

Example Crystal script to build a standalone command-line client using Micrate. Requires the desired database driver and uses Micrate::Cli.run.

```crystal
#! /usr/bin/env crystal
#
# To build a standalone command line client, require the
# driver you wish to use and use `Micrate::Cli`.
#

require "micrate"
require "pg"

Micrate::DB.connection_url = "postgresql://..."
Micrate::Cli.run
```

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

### Check Current Database Version

Source: https://github.com/amberframework/micrate/blob/master/README.md

Command to retrieve the current version of the database migrations applied by Micrate.

```bash
$ micrate dbversion
20160524162446
```

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

### Basic SQL Migration Structure

Source: https://github.com/amberframework/micrate/blob/master/README.md

Defines the basic structure for a Micrate SQL migration file, using '+micrate Up' and '+micrate Down' directives to specify SQL for applying and rolling back.

```sql
-- +micrate Up
-- SQL in section 'Up' is executed when this migration is applied


-- +micrate Down
-- SQL section 'Down' is executed when this migration is rolled back
```

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

### Redo Last Migration

Source: https://github.com/amberframework/micrate/blob/master/README.md

Command to roll back and then re-apply the last database migration using Micrate.

```bash
$ micrate redo
```

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

### Check Migration Status

Source: https://github.com/amberframework/micrate/blob/master/README.md

Command to display the status of all migrations, indicating which have been applied and which are pending.

```bash
$ micrate status
Applied At                  Migration
=======================================
2016-05-24 16:31:07 UTC  -- 20160524162446_add_users_table.sql
Pending                  -- 20160524163425_add_address_to_users.sql
```

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

### Add Micrate Dependency to Shard.yml

Source: https://github.com/amberframework/micrate/blob/master/README.md

Specifies how to add Micrate as a dependency to a Crystal project's shard.yml file for programmatic usage.

```yaml
dependencies:
  micrate:
    github: amberframework/micrate
```

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

### Rollback Last Migration

Source: https://github.com/amberframework/micrate/blob/master/README.md

Command to roll back the most recently applied database migration using Micrate.

```bash
$ micrate down
```

=== COMPLETE CONTENT === This response contains all available snippets from this library. No additional content exists. Do not make further requests.