check_constraints

The view information_schema.check_constraints contains all check constraints defined on a table.

SELECT * FROM information_schema.check_constraints;

SELECT constraint_schema, table_name, constraint_name, check_clause
  FROM information_schema.check_constraints;

information_schema.check_constraints

column nametyperemarks
constraint_catalogVARCHARAlways NULL
constraint_schemaVARCHAR
constraint_nameVARCHAR
check_clauseVARCHAR
schema_idINTEGERreference to sys.schemas.id
table_idINTEGERreference to sys.tables.id
table_nameINTEGERname of table which has the check constraint
key_idINTEGERreference to sys.keys.id

Note: The last 4 columns (schema_id, table_id, table_name and key_id) are extensions to the view as defined by ISO standard. They provide useful information and simplify filtering and joins with system tables/views in sys schema when needed.