How do I rename a column in a database table using SQL?

Question

If I wish to simply rename a column (not change its type or constraints, just its name) in an SQL database using SQL, how do I do that? Or is it not possible?

This

Answer 1

On PostgreSQL (and many other RDBMS), you can do it with regular ALTER TABLE statement:

=> SELECT * FROM Test1;
 id | foo | bar 
----+-----+-----
  2 |   1 |   2

=> ALTER TABLE Test1 RENAME COLUMN foo TO baz;
ALTER TABLE

=> SELECT * FROM Test1;
 id | baz | bar 
----+-----+-----
  2 |   1 |   2

Answer 2

In Informix, you can use:

RENAME COLUMN TableName.OldName TO NewName;

This was implemented before the SQL standard addressed the issue - if it is addressed in the SQL standard. My copy of the SQL 9075:2003 standard does not show it as being standard (amongst other things, RENAME is not one of the keywords). I don't know whether it is actually in SQL 9075:2008.

Answer 3

The standard would be ALTER TABLE, but that's not necessarily supported by every DBMS you're likely to encounter, so if you're looking for an all-encompassing syntax, you may be out of luck.

Answer 4

ALTER TABLE is standard SQL. But it's not completely implemented in many database systems.

Answer 5

In MySQL, the syntax is ALTER TABLE ... CHANGE:

ALTER TABLE <table_name> CHANGE <column_name> <new_column_name> <data_type> ...

Note that you can't just rename and leave the type and constraints as is; you must retype the data type and constraints after the new name of the column.