Go through a table in the database and chance all value=0 to value=3

[steve_683]

This is quite a novice question, and hopefully one with an easy answer.

 

I want to go through a MySQL table on my server and change value=`0` to value=`3` everywhere where attributeid==`2` (and value==`0`). Here`s what the table looks like:

 

| attributeid | userid | value |

-----------------------------

|  1          |    1    |    1    |

|  2          |    1    |    0    |

|  3          |    1    |    45  |

|  1          |    2    |    1    |

|  2          |    2    |    4    |

...and so on

 

So I guess I run the following code:

 

$newvalue = 3;

mysql_query("UPDATE name_of_table SET value='$newvalue' WHERE (value=='0' AND attributeid=='2')");

 

Is this going to work, or am I potentially going to screw-up something? I'm a very novice programmer, and I'm very worried I'm going to make some kind of serious mistake.

[kickstart]

Hi

 

Pretty much, although SQL does not require double == when checking a value (single = will be fine).

 

All the best

 

Keith

[PFMaBiSmAd]

Testing code involves actually trying something and seeing if the results are what you expect, this is why you run tests on a development system where the data either does not matter or you have a backup of it that you can easily restore if something goes wrong.

 

Edit: following is basically the same as posted above -

 

The only thing you need to change is the double == signs should be single =

 

In SQL a comparison is only one = sign.