sandy sandy - 6 months ago 33
SQL Question

Delete column from SQLite table

I have a problem: I need to delete a column from my SQLite database. I wrote this query

alter table table_name drop column column_name


but it does not work. Please help me.

Answer

From: http://www.sqlite.org/faq.html:

(11) How do I add or delete columns from an existing table in SQLite.

SQLite has limited ALTER TABLE support that you can use to add a column to the end of a table or to change the name of a table. If you want to make more complex changes in the structure of a table, you will have to recreate the table. You can save existing data to a temporary table, drop the old table, create the new table, then copy the data back in from the temporary table.

For example, suppose you have a table named "t1" with columns names "a", "b", and "c" and that you want to delete column "c" from this table. The following steps illustrate how this could be done:

BEGIN TRANSACTION;
CREATE TEMPORARY TABLE t1_backup(a,b);
INSERT INTO t1_backup SELECT a,b FROM t1;
DROP TABLE t1;
CREATE TABLE t1(a,b);
INSERT INTO t1 SELECT a,b FROM t1_backup;
DROP TABLE t1_backup;
COMMIT;