Creating Table Constraints

Search…
Sometimes you want to add constraints on a table level, rather than a column level. The following methods will let you accomplish that.
index
Create a generic index from one or more columns.
Argument
Type
Required
Default
Description
columns
string or array
true
​
The column or array of columns that make up the index.
name
string
false
A generated name consisting of the table name and column name(s).
The name of the index constraint.
​
​
​
​
​
Example:
SchemaBuilder
schema.create( "users", function( table ) {
    table.string( "first_name" );
    table.string( "last_name" );
    table.index( [ "first_name", "last_name" ], "idx_users_full_name" );
} );
SQL (MySQL)
CREATE TABLE `users` (
    `first_name` VARCHAR(255) NOT NULL,
    `last_name` VARCHAR(255) NOT NULL,
    INDEX `idx_users_full_name` (`first_name`, `last_name`)
)
foreignKey
Create a foreign key constraint from one or more columns. Follow up this call with calls to the TableIndex's references and onTable methods.
Argument
Type
Required
Default
Description
columns
string or array
true
​
The column or array of columns that references a key or keys on another table.
name
string
false
A generated name consisting of the table name and column name(s).
The name of the foreign key constraint.
Example:
SchemaBuilder
schema.create( "users", function( table ) {
    table.unsignedInteger( "country_id" );
    table.foreignKey( "country_id" ).references( "id" ).onTable( "countries" );
} );
SQL (MySQL)
CREATE TABLE `users` (
    `country_id` INTEGER UNSIGNED NOT NULL,
    CONSTRAINT `fk_users_country_id` FOREIGN KEY (`country_id`) REFERENCES `countries` (`id`) ON UPDATE NO ACTION ON DELETE NO ACTION
)
primaryKey
Create a primary key constraint from one or more columns.
Argument
Type
Required
Default
Description
columns
string or array
true
​
The column or array of columns that make up the primary key.
name
string
false
A generated name consisting of the table name and column name(s).
The name of the primary key constraint.
​
​
​
​
​
Example:
SchemaBuilder
schema.create( "posts_users", function( table ) {
    table.unsignedInteger( "post_id" ).references( "id" ).onTable( "posts" );
    table.unsignedInteger( "user_id" ).references( "id" ).onTable( "users" );
    table.primaryKey( [ "post_id", "user_id" ], "pk_posts_users" );
} );
SQL (MySQL)
CREATE TABLE `posts_users` (
    `post_id` VARCHAR(255) NOT NULL,
    `user_id` VARCHAR(255) NOT NULL,
    INDEX `idx_users_full_name` (`first_name`, `last_name`),
    CONSTRAINT `fk_posts_users_post_id` FOREIGN KEY (`post_id`) REFERENCES `posts` (`id`) ON UPDATE NO ACTION ON DELETE NO ACTION,
    CONSTRAINT `fk_posts_users_user_id` FOREIGN KEY (`user_id`) REFERENCES `users` (`id`) ON UPDATE NO ACTION ON DELETE NO ACTION,
    CONSTRAINT ""pk_users_first_name_last_name"" PRIMARY KEY (""first_name"", ""last_name"")
)
unique
Create a unique constraint from one or more columns.
Argument
Type
Required
Default
Description
columns
string or array
true
​
The column or array of columns that make up the unique constraint.
name
string
false
A generated name consisting of the table name and column name(s).
The name of the unique constraint.
Example:
SchemaBuilder
schema.create( "users", function( table ) {
    table.increments( "id" );
    table.string( "username ");
    table.unique( "username" );
} );
SQL (MySQL)
CREATE TABLE `users` (
    `id` INTEGER UNSIGNED NOT NULL AUTO_INCREMENT,
    UNIQUE (`username`)
)
Schema Builder - Previous
Column Constraints
Next - Schema Builder
Alter
Last modified 1mo ago
Copy link
Outline
index
foreignKey
primaryKey
unique