W dream

Posted on Sunday, 3rd May 2009 by Balazs

To delete records where only a field is duplicated, we can use a similar technique to the general duplicate removal technique:

CREATE TABLE temp AS SELECT DISTINCT ON (email) * FROM table_to_deduplicate;
DROP TABLE table_to_deduplicate;
ALTER TABLE temp RENAME TO table_to_deduplicate;

Be mindful of the fact that this process will not preserve the constraints on the original table. So [...]

Tags: DB2, IBM, MySQL, Oracle, PostgreSQL
Posted in DB2, Technology | Comments (Comments)

Posted on Sunday, 3rd May 2009 by Balazs

To delete dupplicate records in SQL, the following sequence of commands will do the trick:

CREATE TABLE temp AS SELECT DISTINCT * FROM table_to_deduplicate;
DROP TABLE table_to_deduplicate;
ALTER TABLE temp RENAME TO table_to_deduplicate;

Be mindful of the fact that this process will not preserve the constraints on the original table. So if you have indexes, NOT NULL attributes, primary [...]

Tags: DB2, IBM, MySQL, Oracle, PostgreSQL
Posted in DB2, Technology | Comments (Comments)