Sign InTry Free

REFERENTIAL_CONSTRAINTS

The REFERENTIAL_CONSTRAINTS table provides information about FOREIGN KEY relationships between tables. Note that TiDB currently does not enforce FOREIGN KEY constraints, or perform actions such as ON DELETE CASCADE.

USE information_schema; DESC referential_constraints;
+---------------------------+--------------+------+------+---------+-------+ | Field | Type | Null | Key | Default | Extra | +---------------------------+--------------+------+------+---------+-------+ | CONSTRAINT_CATALOG | varchar(512) | NO | | NULL | | | CONSTRAINT_SCHEMA | varchar(64) | NO | | NULL | | | CONSTRAINT_NAME | varchar(64) | NO | | NULL | | | UNIQUE_CONSTRAINT_CATALOG | varchar(512) | NO | | NULL | | | UNIQUE_CONSTRAINT_SCHEMA | varchar(64) | NO | | NULL | | | UNIQUE_CONSTRAINT_NAME | varchar(64) | YES | | NULL | | | MATCH_OPTION | varchar(64) | NO | | NULL | | | UPDATE_RULE | varchar(64) | NO | | NULL | | | DELETE_RULE | varchar(64) | NO | | NULL | | | TABLE_NAME | varchar(64) | NO | | NULL | | | REFERENCED_TABLE_NAME | varchar(64) | NO | | NULL | | +---------------------------+--------------+------+------+---------+-------+ 11 rows in set (0.00 sec)
CREATE TABLE test.parent ( id INT NOT NULL AUTO_INCREMENT, PRIMARY KEY (id) ); CREATE TABLE test.child ( id INT NOT NULL AUTO_INCREMENT, name varchar(255) NOT NULL, parent_id INT DEFAULT NULL, PRIMARY KEY (id), CONSTRAINT fk_parent FOREIGN KEY (parent_id) REFERENCES parent (id) ON UPDATE CASCADE ON DELETE RESTRICT ); SELECT * FROM referential_constraints\G
*************************** 1. row *************************** CONSTRAINT_CATALOG: def CONSTRAINT_SCHEMA: test CONSTRAINT_NAME: fk_parent UNIQUE_CONSTRAINT_CATALOG: def UNIQUE_CONSTRAINT_SCHEMA: test UNIQUE_CONSTRAINT_NAME: PRIMARY MATCH_OPTION: NONE UPDATE_RULE: CASCADE DELETE_RULE: RESTRICT TABLE_NAME: child REFERENCED_TABLE_NAME: parent 1 row in set (0.00 sec)

Was this page helpful?

Download PDFRequest docs changesAsk questions on Discord
Playground
One-stop & interactive experience of TiDB's capabilities WITHOUT registration.
Products
TiDB
TiDB Dedicated
TiDB Serverless
Pricing
Get Demo
Get Started
© 2024 PingCAP. All Rights Reserved.
Privacy Policy.