[SOLVED] drop table if exists question

[dennismonsewicz]

I have a SQL command that drops 3 different tables if they exist.

 

can you make this into one sql statement?

 

Example:

 

DROP TABLE IF EXIST `table1`, `table2`, `table3`;

[premiso]

Why not find out for yourself?

 

http://dev.mysql.com/doc/refman/5.1/en/drop-table.html

 

According to that, yes you can.

[dennismonsewicz]

i actually found that site right after i posted the question... sorry for not googling the answer myself!

[Maq]

Can you drop a table that doesn't exist...

[premiso]

Can you drop a table that doesn't exist...

 

The IF EXISTS part is to throw an error. This is used mainly for development/installer scripts. Incase someone is re-installing or you dont want to alter your tables you can just drop the table if it exists then re-create it.

 

I use it all the time in my installer scripts.

[PFMaBiSmAd]

Edit: Basically says the same as above ^^^

 

That syntax is used to prevent an error if the table does not exist when you try to drop it. Otherwise, you must first query to determine if it exists before you execute the DROP statement.

[Maq]

I know this topic is solved but I found this little function online that is a little more versatile.

 

function table_exists($table)
{
   $connection = mysql_connect($myinfo_host, $myinfo_user, $myinfo_pass) or die(mysql_error());
   mysql_select_db($myinfo_base, $connection) or die(mysql_error());
   if(!(mysql_query("SELECT * FROM $table")))
   {
      //what to do if table doesn't exist
   }
   mysql_close($connection);
}

[premiso]

I know this topic is solved but I found this little function online that is a little more versatile.

 

function table_exists($table)
{
   $connection = mysql_connect($myinfo_host, $myinfo_user, $myinfo_pass) or die(mysql_error());
   mysql_select_db($myinfo_base, $connection) or die(mysql_error());
   if(!(mysql_query("SELECT * FROM $table")))
   {
      //what to do if table doesn't exist
   }
   mysql_close($connection);
}

 

But why when DROP TABLE IF EXISTS is soo much simpler than doing that? lol

[Maq]

My whole point was to put it in a function so that you can have more conditionals.  It's also better if you're going to invoke this function a lot.