developers

developers@lists.mariadb.org

June 2012

16 participants
21 discussions

[Maria-developers] WL#252 New (by DonQuichote): IF (NOT) EXIST clauses for ALTER TABLE
by worklog-noreply＠askmonty.org 01 Jun '12

01 Jun '12

----------------------------------------------------------------------- WORKLOG TASK -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- TASK...........: IF (NOT) EXIST clauses for ALTER TABLE CREATION DATE..: Fri, 01 Jun 2012, 09:35 SUPERVISOR.....: IMPLEMENTOR....: COPIES TO......: CATEGORY.......: Server-RawIdeaBin TASK ID........: 252 (https://askmonty.org/worklog/?tid=252) VERSION........: WorkLog-4.0 STATUS.........: Un-Assigned PRIORITY.......: 60 WORKED HOURS...: 0 ESTIMATE.......: 0 (hours remain) ORIG. ESTIMATE.: 0 PROGRESS NOTES: DESCRIPTION: MySQL / MariaDB SQL is great as a functional language: you tell what you want and not how to do it. This includes suppressing of errors when the situation you want already exists. So there is a CREATE TABLE IF NOT EXISTS statement, for example (you say that you want the table to exist, not that it has to be built right now). It would be nice if altering a table could be done the same way: ALTER TABLE SomeTable ADD COLUMN IF NOT EXISTS SomeColumn ... ALTER TABLE SomeTable DROP COLUMN IF EXISTS SomeColumn ... ALTER TABLE SomeTable DROP FOREIGN KEY IF EXISTS SomeConstraint ... This would make definition scripts more legible and more friendly to existing databases. It would facilitate what I call "repeatable scripts", that can both create a new database and update an existing one to the latest structure. Mind you, this is already possible using temporary stored procedures (as shown in http://www.howtoforge.com/node/4833) but it would make definition scripts more maintainable and the SQL language more consistent. ESTIMATED WORK TIME ESTIMATED COMPLETION DATE ----------------------------------------------------------------------- WorkLog (v4.0.0)

1 0