PHP queries and deletes repeated data in multiple columns of the database (implemented using array functions), multi-column array _ PHP Tutorial

PHP queries and deletes multiple repeated data columns in the database (implemented using array functions) and multiple array columns. PHP queries and deletes repeated data in multiple columns of the database (implemented using array functions). This article describes how PHP queries and deletes repeated data in multiple columns of the database. Share with PHP how to query and delete multiple columns of duplicate data in a database (implemented using array functions) and multi-column arrays

This example describes how to query and delete multiple duplicate data columns in a database using PHP. We will share this with you for your reference. The details are as follows:

<? Php $ con = mysql_connect ("localhost", "root", ""); if (! $ Con) {die ('could not connect: '. mysql_error ();} $ db_selected = mysql_select_db ("test_db", $ con); if (! $ Db_selected) {die ("Can/'t use test_db :". mysql_error ();} $ SQL = "SELECT * FROM friend"; $ result = mysql_query ($ SQL, $ con); while ($ myrow = mysql_fetch_row ($ result )) {$ arr_data [$ myrow [0] = $ myrow [1]. "-". $ myrow [2];} $ arr_unique = array_unique ($ arr_data); $ arr_rep = array_diff_assoc ($ arr_data, $ arr_unique); // display the echo count ($ arr_data) before and after ). "-". count ($ arr_unique); foreach ($ arr_rep as $ key => $ value) {$ SQL _del = "DELETE F ROM friend WHERE id = '{$ key}' "; $ result = mysql_query ($ SQL _del, $ con) ;}// some codes mysql_close ($ con);?>