Jump to content

Archived

This topic is now archived and is closed to further replies.

paolinaaaaaaa

How to check if a tuple is already in a mysql database with php

Recommended Posts

Probably a really stupid question but I am a total beginner ???...so here is the scenario:

I have a html form in which people can insert a series of values.
On pressing submit these values should be used to insert a tuple in a mysql database using php.
However the values could already be in the database.
I therefore need to check that beforehand.
In short I need to do:

IF (tuple already in db)
return tuple primary key
ELSE
insert tuple in db
return tuple primary key

how could I do this?
I have tried doing a select and seeing if it returns false but either I get a value (if the tuple is in the db) or I get an error (if the tuple is not in the db) and my script doesn't reach the end.

Thank you very much,

Paolina

Share this post


Link to post
Share on other sites
There are a few ways you can do this.  However, no select query should ever return an error, just an empty result set, a boundary condition that you can easily check.  Anyway, you could always do an INSERT IGNORE, provided you have an appropriate unique key across the relevant column; alternatively, you could do the select, and if no result, then insert, and pull back the last_insert_id.

Share this post


Link to post
Share on other sites

×

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.