Msg 1909, Level 16, State 1, Line 1
Cannot use duplicate column names in %S_MSG. Column name ‘%.*ls’ listed more than once.
This error message appears when you try to use a column name more than once for an operation.
The T-SQL statement can be parsed, but causes the error at runtime.
Error of the Severity Level 16 are generated by the user and can be fixed by the SQL Server user. The statement cannot be executed this way. Column names in the column list for this operation must be unique.
All versions of SQL Server
IF OBJECT_ID(‘tempdb..#t’) > 0
DROP TABLE #t
CREATE TABLE #t
id INT NOT NULL IDENTITY
CREATE INDEX IX_t_id ON #t(id, id)
In the above example we try to specify a column name more than once when creating an index. This raises the error.