Create Table

Basic Table Creation

Use create_table to define a new table:

DB::Migrate.migrate("create_users", client) do
	create_table :users do
		primary_key
		column :name, "TEXT NOT NULL"
		column :email, "TEXT UNIQUE"
		timestamps
	end
end

Conditional Table Creation

Use create_table? to create a table only if it doesn't already exist:

DB::Migrate.migrate("safe_create_users", client) do
	create_table? :users do
		primary_key
		column :name, "TEXT NOT NULL"
	end
end

Column Definitions

Basic Columns

Define columns with their SQL type:

create_table :products do
	column :name, "TEXT NOT NULL"
	column :price, "DECIMAL(10,2)"
	column :description, "TEXT"
	column :active, "BOOLEAN DEFAULT TRUE"
end

Primary Keys

Add an auto-incrementing primary key:

create_table :users do
	primary_key # Creates 'id' column
		# Other columns...
end

# Custom primary key name
create_table :users do
	primary_key :user_id
		# Other columns...
end

The primary key uses database-appropriate types:

• PostgreSQL: BIGSERIAL PRIMARY KEY
• MariaDB/MySQL: BIGINT AUTO_INCREMENT PRIMARY KEY

Timestamps

Add created_at and updated_at columns:

create_table :posts do
	primary_key
	column :title, "TEXT NOT NULL"
	timestamps # Adds created_at and updated_at
end

Column Options

Constraints

create_table :users do
	primary_key
	column :email, "TEXT NOT NULL", unique: true
	column :age, "INTEGER", null: false
	column :status, "TEXT", default: "'active'"
end

Indexes

Create indexes on columns:

create_table :users do
	primary_key
	column :email, "TEXT NOT NULL", unique: true, index: true
	column :name, "TEXT", index: true
end

Advanced Examples

Composite Indexes

create_table :user_preferences do
	primary_key
	column :user_id, "BIGINT NOT NULL"
	column :preference_key, "TEXT NOT NULL"
	column :preference_value, "TEXT"
	
		# Create composite index
	index [:user_id, :preference_key], unique: true
end

Foreign Key References

create_table :posts do
	primary_key
	column :user_id, "BIGINT NOT NULL"
	column :title, "TEXT NOT NULL"
	column :content, "TEXT"
	timestamps
	
		# Note: Foreign key constraints are defined separately
		# This just creates the reference column
end

Database-Specific Types

create_table :analytics do
	primary_key
	column :event_data, "JSONB"  # PostgreSQL
	column :tags, "JSON"         # MariaDB/MySQL
	column :metadata, "TEXT"     # Universal fallback
end

Options

Drop Existing Table

Replace an existing table:

create_table :users, drop_if_exists: true do
	primary_key
	column :name, "TEXT NOT NULL"
end

Temporary Tables

create_table :temp_data, temporary: true do
	column :id, "BIGINT"
	column :data, "TEXT"
end

Note: Temporary table support depends on your database adapter implementation.