Column Constraints

A TableIndex can be created directly from a Blueprint or from a existing Column. The TableIndex includes methods for further configuring the index which is required when defining foreign keys.
references
Set the referencing column for a foreign key relationship. For example, id for a country_id column.
Argument
Type
Required
Default
Description
columns
any
true
​
A column or array of columns that represents the foreign key reference.
Example:
SchemaBuilder
schema.create( "users", function( table ) {
    table.unsignedInteger( "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
)
onTable
Sets the referencing table for a foreign key relationship. For example, countries for a country_id column.
Argument
Type
Required
Default
Description
table
string
true
​
The referencing table name.
Example:
SchemaBuilder
schema.create( "users", function( table ) {
    table.unsignedInteger( "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
)
onUpdate
Set the strategy for updating foreign keys when the parent key is updated.
Argument
Type
Required
Default
Description
option
string
true
​
The strategy to use. Available values are: RESTRICT, CASCADE, SET NULL, NO ACTION, SET DEFAULT
Example:
SchemaBuilder
schema.create( "users", function( table ) {
    table.unsignedInteger( "country_id" )
        .references( "id" )
        .onTable( "countries" )
        .onUpdate( "CASCADE" );
} );
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 CASCADE ON DELETE NO ACTION
)
onDelete
Set the strategy for updating foreign keys when the parent key is deleted.
Argument
Type
Required
Default
Description
option
string
true
​
The strategy to use. Available values are: RESTRICT, CASCADE, SET NULL, NO ACTION, SET DEFAULT
Example:
SchemaBuilder
schema.create( "users", function( table ) {
    table.unsignedInteger( "country_id" )
        .references( "id" )
        .onTable( "countries" )
        .onDelete( "SET NULL" );
} );
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 SET NULL
)
Schema Builder - Previous
Column Modifiers
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Creating Table Constraints
Last updated 3 years ago
Argument	Type	Required	Default	Description
columns	any	`true`		A column or array of columns that represents the foreign key reference.