Search for all occurrences of a string in a mysql database

A simple solution would be doing something like this:

mysqldump -u myuser --no-create-info --extended-insert=FALSE databasename | grep -i "<search string>"

I was looking for this myself when we changed domain on our Wordpress website. It can't be done without some programming so this is what I did.

<?php  
  header("Content-Type: text/plain");

  $host = "localhost";
  $username = "root";
  $password = "";
  $database = "mydatabase";
  $string_to_replace  = 'old.example.com';
  $new_string = 'new.example.com';

  // Connect to database server
  mysql_connect($host, $username, $password);

  // Select database
  mysql_select_db($database);

  // List all tables in database
  $sql = "SHOW TABLES FROM ".$database;
  $tables_result = mysql_query($sql);

  if (!$tables_result) {
    echo "Database error, could not list tables\nMySQL error: " . mysql_error();
    exit;
  }

  echo "In these fields '$string_to_replace' have been replaced with '$new_string'\n\n";
  while ($table = mysql_fetch_row($tables_result)) {
    echo "Table: {$table[0]}\n";
    $fields_result = mysql_query("SHOW COLUMNS FROM ".$table[0]);
    if (!$fields_result) {
      echo 'Could not run query: ' . mysql_error();
      exit;
    }
    if (mysql_num_rows($fields_result) > 0) {
      while ($field = mysql_fetch_assoc($fields_result)) {
        if (stripos($field['Type'], "VARCHAR") !== false || stripos($field['Type'], "TEXT") !== false) {
          echo "  ".$field['Field']."\n";
          $sql = "UPDATE ".$table[0]." SET ".$field['Field']." = replace(".$field['Field'].", '$string_to_replace', '$new_string')";
          mysql_query($sql);
        }
      }
      echo "\n";
    }
  }

  mysql_free_result($tables_result);  
?>

Hope it helps anyone who's stumbling into this problem in the future :)

Scott gives a good example of how to do it, but the question is why would you want to? If you need to do a find-and-replace on a specific string, you could also try doing a mysqldump of your database, do a find-and-replace in an editor, then re-load the database.

Maybe if you gave some background on what you are trying to achieve, others might be able to provide better answers.

In unix machines, if the database is not too big:

mysqldump -u <username> -p <password> <database_name> --extended=FALSE | grep <String to search> | less -S

Not an elegant solution, but you could achieve it with a nested looping structure

// select tables from database and store in an array

// loop through the array
foreach table in database
{
    // select columns in the table and store in an array

    // loop through the array
    foreach column in table
    {
        // select * from table where column = url
    }
}

You could probably speed this up by checking which columns contain strings while building your column array, and also by combining all the columns per table in one giant, comma-separated WHERE clause.