Error while using MAX function in update clause

[RuthC]

Hi
i want to update the recorde like this

UPDATE category_shops SET category_shops_id = (SELECT MAX(`category_shops_id`)+1 FROM category_shops) WHERE category_shops_id = 0 AND shop_id= 14856 AND category_id = 14
 

but getting the error
"1093 - You can't specify target table 'category_shops' for update in FROM clause "

please help me

[rpnew]

Hi
i want to update the recorde like this

UPDATE category_shops SET category_shops_id = (SELECT MAX(`category_shops_id`)+1 FROM category_shops) WHERE category_shops_id = 0 AND shop_id= 14856 AND category_id = 14
 

but getting the error
"1093 - You can't specify target table 'category_shops' for update in FROM clause "

please help me

Its because you are Updating the table which you are using in the select clause. Which is not allowed or cant be done...
Check the following link for MySql 5.0 manual...

Update Query for Mysql

and read the last line before user comments.....

same is true for MySql 5.1 and 6.0 also. check their respective manual as well.. for update queries....
So what you can do here is use "select" clause first assign its value to some variable and then use it in "update" query... try this if it works..

Regards,
RP

[mwasif]

Hi RuthC,

Kindly use appropriate CODE tags when posting code.Checkout the Supported CODE tags.

[RuthC]

Thanks Its Working

 
    $text = "Test Text";
    $image = imagecreatetruecolor(200,45);
    $white = imagecolorallocate($image,255,255,255);
    imagefill($image,0,0,$white);
    $red = imagecolorallocate($image,255,0,0);
    $degrees = (173/strlen($text)/3.7);
    for ($i=0;$i<strlen($text);$i++) {
        $a = ($degrees*$i)+246;
        $cos = cos(deg2rad($a));
        $sin = sin(deg2rad($a));
        $x = 180;
        $y = 0;
        $xt = round($cos*($x) - $sin*($y));
        $yt = round($sin*($x) + $cos*($y));
        imagettftext($image,12,280-($a),80+$xt,200+$yt,$red,"C:/WINDOWS/Fonts/verdana.TTF",$text[$i]);
    }
    header("Content-type: image/jpeg");
    imagejpeg($image,"",100);
    imagedestroy($image);