MySQL 8.4 Release Notes
REFERENTIAL_CONSTRAINTS 表提供关于外键的信息。The REFERENTIAL_CONSTRAINTS table
provides information about foreign keys.
REFERENTIAL_CONSTRAINTS 表有以下列：The REFERENTIAL_CONSTRAINTS table has
these columns:
CONSTRAINT_CATALOGCONSTRAINT_CATALOG约束所属的目录名称。该值始终为
def。The name of the catalog to which the constraint belongs. This value is alwaysdef.CONSTRAINT_SCHEMACONSTRAINT_SCHEMA约束所属的模式（数据库）名称。The name of the schema (database) to which the constraint belongs.
CONSTRAINT_NAMECONSTRAINT_NAME约束的名称。The name of the constraint.
UNIQUE_CONSTRAINT_CATALOG包含约束所引用的唯一约束的目录名称。此值始终为
def。The name of the catalog containing the unique constraint that the constraint references. This value is alwaysdef.UNIQUE_CONSTRAINT_SCHEMA包含约束所引用的唯一约束的模式的名称。The name of the schema containing the unique constraint that the constraint references.
UNIQUE_CONSTRAINT_NAME约束所引用的唯一约束的名称。The name of the unique constraint that the constraint references.
MATCH_OPTION约束
MATCH属性的值。目前唯一有效的值是NONE。The value of the constraintMATCHattribute. The only valid value at this time isNONE.UPDATE_RULE约束
ON UPDATE属性的值。可能的值有CASCADE、SET NULL、SET DEFAULT、RESTRICT、NO ACTION。The value of the constraintON UPDATEattribute. The possible values areCASCADE,SET NULL,SET DEFAULT,RESTRICT,NO ACTION.DELETE_RULE约束
ON DELETE属性的值。可能的值有CASCADE、SET NULL、SET DEFAULT、RESTRICT、NO ACTION。The value of the constraintON DELETEattribute. The possible values areCASCADE,SET NULL,SET DEFAULT,RESTRICT,NO ACTION.TABLE_NAMETABLE_NAME表的名称。该值与
TABLE_CONSTRAINTS表中的值相同。The name of the table. This value is the same as in theTABLE_CONSTRAINTStable.REFERENCED_TABLE_NAME约束引用的表名称。The name of the table referenced by the constraint.