Msg 3727, Level 16, State 0, Line 1
Could not drop constraint. See previous errors.
This error message appears when you try to DROP a constraint, but this however was, due to an error, not successfully completed.
The T-SQL statement can be parsed, but causes the error at runtime.
Error of the Severity Level 15 are generated by the user and can be fixed by the SQL Server user. The preceeding error must be corrected so that this statement can successfully be executed.
All versions of SQL Server
CREATE TABLE t
c1 INT NOT NULL CONSTRAINT DF_c1 DEFAULT 0
ALTER TABLE t
DROP CONSTRAINT DF_c11
DROP TABLE t
In the above example the error is raised by the typo in the constraint name. Because an error was raised before the constraint could be dropped, this error is raised.