MySQL DDL API Reference

`DDL`

4 methods

Statements that define or modify the database schema.

CREATE TABLE [IF NOT EXISTS] tbl (col type [constraints], ...)

Creates a new table with the given columns and table-level constraints.

Name	Type	Description
tbl	identifier	Table name.
type	datatype	INT, VARCHAR(n), DATETIME, DECIMAL(p,s), etc.
constraints	constraint	NOT NULL, DEFAULT, AUTO_INCREMENT, PRIMARY KEY.

void

mysql

CREATE TABLE users (
  id BIGINT AUTO_INCREMENT PRIMARY KEY,
  email VARCHAR(255) NOT NULL UNIQUE,
  created_at DATETIME DEFAULT CURRENT_TIMESTAMP
);

ALTER TABLE tbl ADD [COLUMN] col type | DROP COLUMN col | MODIFY col type

Adds, removes or modifies columns and constraints on an existing table.

Name	Type	Description
tbl	identifier	Table to alter.
col	identifier	Column to add, drop or modify.

void

mysql

ALTER TABLE users
  ADD COLUMN last_login DATETIME NULL,
  MODIFY email VARCHAR(320) NOT NULL;

CREATE [UNIQUE] INDEX name ON tbl (col, ...) [USING BTREE]

Creates a secondary index on one or more columns to speed up lookups; UNIQUE enforces uniqueness.

void

mysql

CREATE UNIQUE INDEX idx_users_email ON users (email);

CONSTRAINT name PRIMARY KEY|FOREIGN KEY|UNIQUE|CHECK (cols)

Table-level constraint clause enforcing integrity rules on one or more columns.

Name	Type	Description
name	identifier	Optional constraint name.
cols	column-list	Columns the constraint applies to.

void

mysql

CONSTRAINT fk_orders_user
  FOREIGN KEY (user_id) REFERENCES users(id)
  ON DELETE CASCADE ON UPDATE RESTRICT