28.4.13 The INFORMATION_SCHEMA INNODB_FOREIGN_COLS Table

The INNODB_FOREIGN_COLS table provides status information about InnoDB foreign key columns.

For related usage information and examples, see Section 17.15.3, “InnoDB INFORMATION_SCHEMA Schema Object Tables”.

The INNODB_FOREIGN_COLS table has these columns:

• ID

  The foreign key index associated with this index key field; the same value as INNODB_FOREIGN.ID.

• FOR_COL_NAME

  The name of the associated column in the child table.

• REF_COL_NAME

  The name of the associated column in the parent table.

• POS

  The ordinal position of this key field within the foreign key index, starting from 0.

Example

mysql> SELECT * FROM INFORMATION_SCHEMA.INNODB_FOREIGN_COLS WHERE ID = 'test/fk1'\G
*************************** 1. row ***************************
          ID: test/fk1
FOR_COL_NAME: parent_id
REF_COL_NAME: id
         POS: 0

Notes

• You must have the PROCESS privilege to query this table.

• Use the INFORMATION_SCHEMA COLUMNS table or the SHOW COLUMNS statement to view additional information about the columns of this table, including data types and default values.