Column Constraints
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
)
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
)
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
)
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
)