sysconstraints (all databases)

Contains mappings of constraints to the objects that own the constraints.

Column Datatype Description
constid int Constraint ID.
id int ID of the table that owns the constraint.
colid tinyint ID of the column on which the constraint is defined. 0 if a table constraint.
spare1 tinyint Reserved.
status int 1    PRIMARY KEY constraint
2    UNIQUE KEY constraint
3    FOREIGN KEY constraint
4    CHECK constraint
5    DEFAULT constraint
16    Column-level constraint
32    Table-level constraint
actions int Reserved.
error int Reserved.

Index

csysconstraints clustered located on id, colid

unc1sysconstraints nonclustered, unique on constid