PHP/MySQL Update and Insert based on two tables - php

Question

I have been going over this for a few days now and keep reaching stumbling blocks. I am trying to select a unique id from table2 and match it against an id in table1. If the id is matched, update the row in table1 and remove the record from table2. If there is no match then insert the record into table1.
I have got to a point where I can update the records and insert the new ones but I cannot seem to delete the matched record before the insert therefore creating a duplicate. I have tried a delete join query after the update but because the new logon_id has a character prepended to it, it no longer matches in table2.
I was doing an update join before for updates but I had too many queries going on so trying to keep it simple.
Any advice? Still a newb at this game.
$table2_query = "SELECT * FROM table2";
$table2_result = mysql_query($table2_query);
$table2_count = mysql_num_rows($table2_result);
if($table2_count == 0) {
if(mysql_error()) {
echo 'Error: '.mysql_error();
}
}
while($table2_row = mysql_fetch_array($table2_result, MYSQL_ASSOC)) {
$check_number_length = strlen($table2_row['unique_id']);
if($check_number_length < 7) {
if(substr($table2_row['unique_id'], 0, 2) < 35) {
$logon_id = 'n' . $table2_row['unique_id'];
}else {
$logon_id = 'v' . $table2_row['unique_id'];
}
}else {
$logon_id = $table2_row['unique_id'];
}
// Set variables for insert query for creation of a new user record
$first_name = $table2_row['firstname'];
$last_name = $table2_row['lastname'];
$email_address = $table2_row['email'];
$duplicates_query = "SELECT * FROM table1 WHERE '$logon_id' = logon_id";
$duplicates_result = mysql_query($duplicates_query);
$duplicates_row = mysql_fetch_array($duplicates_result);
$duplicates_count = mysql_num_rows($duplicates_result);
if($duplicates_count == 0) {
if(mysql_error()) {
echo 'Error: '.mysql_error();
}
}else {
$update_records_query = "UPDATE table1 SET first_name='$first_name', last_name='$last_name', email_address='$email_address'";
$update_records_result = mysql_query($update_records_query);
$update_records_count = mysql_affected_rows();
echo $update_records_count;
}
$create_records_query = "INSERT INTO table1 (first_name, last_name, email_address) VALUES ('$first_name', '$last_name', '$email_address')";
$create_records_result = mysql_query($create_records_query);
$create_records_count = mysql_affected_rows();
if($create_records_count == 0){
if(mysql_error()){
echo 'Error: '.mysql_error();
}
}
echo $create_records_count . ' record(s) created.';
}

Answer 1

$res = mysql_query ("SELECT count(table1.login_id) AS count FROM table2 LEFT JOIN table1 ON table2.login_id = table1.login_id WHERE table2.login_id = \"".$login_id."\";") or die ("Error joining tables");
/*joins both tables together and selects both id's from tables */
$row = mysql_fetch_assoc($res); // should only return one row so grab first
if ($row['count'] > 0) { // check if id exists in both tables (duplicates)
// updates rows from one table into another
mysql_query('UPDATE table1,table2 SET table1.username = table2.username, table1.password = table2.password, table1.email = table2.email WHERE table1.login_id = "'.$login_id.'" AND table2.login_id = "'.$login_id.'";') or die ("error updating table1");
//delete old row
mysql_query('DELETE FROM table2 WHERE login_id = "'.$login_id.'";') or die("error deleting from table2");
}else { // if id doesn't exist in table1
mysql_query ("INSERT INTO table1(username,password,email) SELECT username,password,email FROM table2 where login_id = '".$login_id."';") or die ("error inserting into table1");
}
remove the n at the beginning of login_id on table1
UPDATE table1 set login_id = replace(login_id,"n","");
new update query if remove n at begin of login_id
mysql_query ('UPDATE table1,table2 SET table1.username = table2.username, table1.password = table2.password, table1.email = table2.email WHERE table1.login_id = table2.login_id AND table1.login_id = "'.$login_id.'";');