mysql select to see what fields are there

[jpr]

Hello, I have several columns for one row in my mysql table. I am using php. Is there a query I can use so that I can figure out what columns are there and the names of the columns? I would like to know this to save me some time writing code, if I could just use a loop instead. Thank you for your help!

[laserlight]

Consider [man]mysql_fetch_field/man

[Foo]

In Oracle I know you can issue the query:

"Describe tablename;"

which prints out a list of each field in a table and its parameters. If that's available to you, it would work.

Also, you have available the following:
mysql_field_name( $resultset , $columnindex )

Using this, you can see that you can get the name of a field at a given position (so giving columnindex 1 would give you the field name of column 1, and so on.

[Drakla]

If you just want the names of the fields use a function a bit like this. I'm using my own class so I'll bung in the safe query bit in case it doesn't make sense. You can call this after doing a select, or just give it a tablename for the fields.

function field_names($tableName='')
		{
			$oldRes=$this->res;

		if($tableName)
		{
			$this->safe_query("SELECT * FROM $tableName LIMIT 0",
			"MySQL->field_names ERROR: Table: $tableName does not exist<br>");				
		}			

		$numFields=mysql_num_fields($this->res);
		for($i=0;$i<$numFields;$i++)
			$names[]=mysql_field_name($this->res, $i);

		$this->res=$oldRes;
		return $names;
	}


function safe_query($sql, $message='')
		{
			return $this->res=mysql_query($sql, $this->dbh)
			 OR die('<b>MySQL TERMINATING: </b>'.$message.'<br><b>mysql_error(): </b>'.mysql_error($this->dbh));
		}