Code Inspection: Index is dependent on column

Reports cases when you try to drop columns from indexed tables. This inspection is available in Microsoft SQL Server and Sybase ASE.

Example (Microsoft SQL Server):

CREATE TABLE test_index
(
col  INT NOT NULL,
col2 INT NOT NULL,
col3 INT NOT NULL UNIQUE,
col4 VARCHAR(200)
);

CREATE UNIQUE INDEX aaaa ON test_index (col, col2);

ALTER TABLE test_index
DROP COLUMN col;

You cannot delete the col column because it is in the indexed table. To delete the column, you need to delete the aaaa index first (for example, DROP INDEX aaaa).