how can i make one column as primary key?

[suma2006]

Hi All,
Here i have one table.what i need to do this is make one column as primary key.
How can i achieve that?
Thanking you,
Regards,
Suma

[amitpatel66]

Hi All,
Here i have one table.what i need to do this is make one column as primary key.
How can i achieve that?
Thanking you,
Regards,
Suma

ALTER TABLE <table_name> ADD PRIMARY KEY (<column_name>)

[pbmods]

Heya, Amit.

Please use CODE tags when posting source code:

[CODE=MySQL]
MySQL code goes here.
[/CODE]

[saadshakil]

Would this code convert an existing column or add a new key column? I've been looking to convert a text column to a (unique) primary key without creating the table or column again.
edited:
I think this works in not only making it key, but a unique key:

ALTER TABLE counter ADD CONSTRAINT NEW_UNIQUE UNIQUE (IP(17));

[pbmods]

Heya, Saadshakil. Welcome to TSDN!

ADD PRIMARY KEY creates a new key, not a new column. In fact, the column must exist before you can index it.

[parthi19]

alter table table_name add primary key(column_name)