Modifying second column for primary key

Question

Hello i have table which has a primary key now on the basis of my need i have to create another primary key means the second primary key but its showing this error message

"ALTER TABLE `abc` ADD PRIMARY KEY(`zzz`)
MySQL said: Documentation

#1068 - Multiple primary key define"

Here is the command:

ALTER TABLE `ABC` ADD PRIMARY KEY(`ZZZ`)

One table can have only 1 primary key at a time. You can make it unique key rahter. So your approach is wrong. — Ankit Bajpai, Jun 30 '14 at 06:15
whatever your need is,but you can't have two primary keys in a table,rather you can have composite primary key,check this out http://stackoverflow.com/questions/217945/can-i-have-multiple-primary-keys-in-a-single-table — nobalG, Jun 30 '14 at 06:16

score 1 · Answer 1 · answered Jun 30 '14 at 06:16

1

Its impossible to have more than 1 primary key on single table. You can have composite primary key on combination of two columns.

answered Jun 30 '14 at 06:16

DevelopmentIsMyPassion

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Its possible i have created in past but i dont remember the commands – user3475078 Jun 30 '14 at 06:18
No its not possible. Which database you used? – DevelopmentIsMyPassion Jun 30 '14 at 06:22
@user3475078 i meant in which database you created 2 primary keys on single table? – DevelopmentIsMyPassion Jun 30 '14 at 06:26
ya in single table i had two primary keys – user3475078 Jun 30 '14 at 06:27

score 0 · Answer 2 · answered Jun 30 '14 at 06:15

0

You can only have one primary key. Change the first one or add a unique constraint.

answered Jun 30 '14 at 06:15

Jens

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http://stackoverflow.com/questions/217945/can-i-have-multiple-primary-keys-in-a-single-table – nobalG Jun 30 '14 at 06:16

Modifying second column for primary key

2 Answers2