incrementing a column without having to query the db first

[trandrus]

I'm fairly new to mysql. I have a table with 1 unique/primary column and another called user_id that is unique but doesn't auto increment. When I add someone to the database, I don't know how to increment user_id without querying the db and find the last value first.

 

[spamjim]

Set up that field/column as auto increment in the table definition. When you insert a record, just poke a zero in the field/column and the correct auto-incremented value will appear.

 

[Chris Miller]

I agree with spamjim, but also wonder whether your primary key already is an auto_increment column and you try to have two auto_increment columns - MySQL doesn't support that.

Chriss

 

[spamjim]

Oops...Chris is correct to notice that. I skimmed the question too quickly and misread. What's the point of having two unique columns? You've already got your unique user_id in the primary column. Get rid of the second user_id column.

 

[Chris Miller]

The primary key might be something else, I just thought I also cover that case. But I also can't imagine a case where you want or need that.


Chriss