List all Constraints of the Database:
SELECT * FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS OR SELECT OBJECT_NAME(object_id) AS ConstraintName, SCHEMA_NAME(schema_id) AS SchemaName, type_desc AS ConstraintType FROM sys.objects WHERE type_desc LIKE '%CONSTRAINT'
List Constraints on table column:
Select SysObjects.[Name] As [Contraint Name] ,Tab.[Name] as [Table Name],Col.[Name] As [Column Name] From SysObjects Inner Join (Select [Name],[ID] From SysObjects Where XType = 'U') As Tab On Tab.[ID] = Sysobjects.[Parent_Obj] Inner Join sysconstraints On sysconstraints.Constid = Sysobjects.[ID] Inner Join SysColumns Col On Col.[ColID] = sysconstraints.[ColID] And Col.[ID] = Tab.[ID] WHERE Tab.[Name] ='Employee' AND Col.[Name]='DOB' order by Col.[Name]