Sometimes I’ve needed to add a counter column in a query and I don’t want to add the column with php, so I’ve found this query to put the counter directly in the record set returned out from the query.
set @N = 0;
SELECT @N := @N +1 AS number, name, surname FROM people;
To use it in PHP scripts you have to use 2 query statements:
mysql_query("set @N = 0;");
$rs = mysql_query("SELECT @N := @N +1 AS number, name, surname FROM people");
while ($r=mysql_fetch_array($rs)) {
echo $r['number']." - ".$r['name']." ".$r['surname']."<br/>";
}
Tags: counter, database, MySql, Php, query
Sometimes it’s necessary fix data on the database.
I had to fix on a Microsoft database:
/* MSSQL syntax */
update table_links set url = Replace(url, 'www.link.it/web3', 'www.link.it/web') where url <>''
I had to fix on a MySQL database:
/* MySQL syntax is the same! */
UPDATE table_links SET url =REPLACE(url, '&', '&') where url<>''
The syntax is the same.
This function returns an array with the elements allowed in a ENUM or SET mysql field. This can be usefull if you’re making some automation and need to retrieve those values without writing them in your code:
function set_and_enum_values( $table , $field ){
$query = "SHOW COLUMNS FROM `$table` LIKE '$field'";
$result = mysql_query( $query ) or die( 'Error getting Enum/Set field ' . mysql_error() );
$row = mysql_fetch_array($result);
if(stripos(".".$row[1],"enum(") > 0) $row[1]=str_replace("enum('","",$row[1]);
else $row[1]=str_replace("set('","",$row[1]);
$row[1]=str_replace("','","\n",$row[1]);
$row[1]=str_replace("')","",$row[1]);
$ar = split("\n",$row[1]);
for ($i=0;$i<count($ar);$i++) $arOut[str_replace("''","'",$ar[$i])]=str_replace("''","'",$ar[$i]);
return $arOut ;
}
