How to change a column name in HSQLDB when the existing name is a reserved word?

Question

I'm trying to upgrade our DB from HSQLDB 1.7 to the latest version. Unfortunately someone has named a column "Default". I can't seem to rename this column in SQL (this in 1.7 as the rename has to occur before the upgrade).

I have tried escaping the column:

stmt.executeUpdate("ALTER TABLE table_name ALTER COLUMN \"DEFAULT\" RENAME TO new_name");

and various variations (including '\\" and []) and nothing seems to work, I always get back the following

java.sql.SQLException: Column not found: DEFAULT in statement [ALTER TABLE table_name ALTER COLUMN "DEFAULT"]

I'm clearly missing something?

Answer 1

Unfortunately someone has named a column "Default"

The trouble seems to be the casing. Not only do double quotes "escape" your names, they also make them case-sensitive, unlike non-quoted names, which are case-insensitive in most databases. So you have to use the exact casing when renaming the column:

ALTER TABLE table_name ALTER COLUMN "Default" RENAME TO new_name

... or with JDBC:

stmt.executeUpdate("ALTER TABLE table_name ALTER COLUMN \"Default\" RENAME TO new_name");

Answer 2

From the HSQLDB guide :

All keywords, can be used for database objects if they are double quoted.

So try to use this:

ALTER TABLE "table_name" ALTER COLUMN "DEFAULT" RENAME TO "new_name"

Answer 3

Try to use a Backtick (`).
This should escape the default string quite well.

ALTER TABLE `table_name` ALTER COLUMN `DEFAULT` RENAME TO `new_name`