All the information about integrity checks and rules in a database is held in system tables and views.
System Table  | 
Description  | 
|---|---|
SYS.SYSTABLE  | 
CHECK constraints are held in the view_def column of SYS.SYSTABLE. For views, the view_def holds the CREATE VIEW command that created the view. You can check whether a particular table is a base table or a view by looking at the table_type column, which is BASE or VIEW.  | 
SYS.SYSFOREIGNKEYS  | 
This view presents the foreign key information from the two tables SYS.SYSFOREIGNKEY and SYS.SYSFKCOL in a more readable format.  | 
SYS.SYSCOLUMNS  | 
This view presents the information from the SYS.SYSCOLUMN table in a more readable format. It includes default settings and primary key information for columns.  | 
You can use Interactive SQL to browse these tables and views.