php - (my)SQL delete duplicate DB-entries WHERE ... -

php - (my)SQL delete duplicate DB-entries WHERE ... -

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how delete duplicates on mysql table? 10 answers

hi got db this

db-name: plzahl sample data: code | plz ------------------ 1 8000 1 8000 2 8000 3 8000 2 8001 3 8001 ...

what want delete duplicates leave 1 in table highest "code" column value.

i have not yet unique identifier @ database. improve add together 1 , utilize mysql_fetch_array() , build "deleting array" or utilize foreach fetch "plz", search if count >0 , if, fetch them, sort them , delete count-1 ones?

so far:

<?php mysql_connect("localhost", "mysql_user", "mysql_password") or die("no connection: " . mysql_error()); mysql_select_db("mydb"); $result = mysql_query("select code, plz plzahl"); while ($row = mysql_fetch_array($result, mysql_num)) { //... here goes magic // create query search count $row['plz'] > 0 ? .... } mysql_free_result($result); ?>

thanks code hint!!

do mysql way:

mysql_query('create table plz_new plz'); mysql_query('insert plz (select max(code) code, plz plzahl grouping plz)'); mysql_query('drop table plz'); mysql_query('rename table plz_new plz');

php mysql sql duplicates