The TABLE_CONSTRAINTS table describes which
tables have constraints.
INFORMATION_SCHEMA
Name | SHOW Name | Remarks |
CONSTRAINT_CATALOG | NULL | |
CONSTRAINT_SCHEMA | ||
CONSTRAINT_NAME | ||
TABLE_SCHEMA | ||
TABLE_NAME | ||
CONSTRAINT_TYPE |
Notes:
The CONSTRAINT_TYPE value can be
UNIQUE, PRIMARY KEY, or
FOREIGN KEY.
The UNIQUE and PRIMARY
KEY information is about the same as what you get
from the Key_name field in the output from
SHOW INDEX when the
Non_unique field is 0.
The CONSTRAINT_TYPE column can contain one
of these values: UNIQUE, PRIMARY
KEY, FOREIGN KEY,
CHECK. This is a CHAR
(not ENUM) column. The
CHECK value is not available until we
support CHECK.