CONSTRAINTS WITH HIDDEN ROWS IN A DATABASE

In an embodiment, a constraint is created for a database table. The constraint specifies a condition for a first column in the database table and an action. The action specifies whether data that violates the condition is allowed to be stored in the first column. A value and a specification of a second column in the database table are received from a data source. If the second column is identical to the first column, the value violates the condition, and the action specifies that data that violates the condition is allowed to be stored, the value is stored in a row in the database, the row is marked as hidden, and an identification of the constraint that was violated is stored in the row. A query does not return the row that is marked as hidden.