adding column to all tables in a mysql database (unknown table names)

Question

I need to add a primary key to a set of tables in a given database. I do not know how many tables there will be or what their specific names are. They will all be of the for dat

Answer 1

If you want to fully script this, you can do something like this:

SELECT CONCAT('ALTER TABLE ',
table_schema,
'.',
table_name,
' ADD COLUMN id INT AUTO_INCREMENT NOT NULL PRIMARY KEY FIRST;') AS ddl
INTO OUTFILE '/tmp/alter_table.sql'
FROM information_schema.tables
WHERE table_schema = 'db_name' 
AND table_type = 'base table';

\. /tmp/alter_table.sql

Answer 2

You can do the following to change the columns. This uses a cursor to iterate over the table names and does not use text files or anything. You have to create this as a stored proc as cursors cannot be used outside.

DELIMITER $$

USE `db_name`$$

DROP PROCEDURE IF EXISTS `alter_test_1`$$

CREATE DEFINER=`db_name`@`10.%` PROCEDURE `alter_test_1`()
BEGIN

DECLARE v_finished INTEGER DEFAULT 0;
DECLARE v_table VARCHAR(100) DEFAULT "";
DECLARE stmt VARCHAR(500) DEFAULT "";

DECLARE column_cursor CURSOR FOR
SELECT * FROM `information_schema`.`tables` WHERE table_schema = 'db_name' AND table_name LIKE 'mytables_%';

DECLARE CONTINUE HANDLER
FOR NOT FOUND SET v_finished = 1;

OPEN column_cursor;

alter_tables: LOOP

FETCH column_cursor INTO v_table;
IF v_finished = 1 THEN
LEAVE alter_tables;
END IF;

SET @prepstmt = CONCAT('ALTER TABLE adtracker','.',v_table,'  ADD COLUMN id INT AUTO_INCREMENT NOT NULL;');

PREPARE stmt FROM @prepstmt;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

END LOOP alter_tables;

CLOSE column_cursor;

END$$

DELIMITER ;

Answer 3

   <?php 
            // ====Variable ============
            $sServerHost="localhost";
            $sLocalHost="localhost";
            $sServerUser="root";
            $sLocalUser="root";
            $sServerPassword="";
            $sLocalPassword="";
            $sLocalDatabaseName="test";
            $sServerDatabaseName="test";
            $Add_columnname="session_language";
            // ====db connection============
            $conn = @mysql_connect($sServerUser,$sServerUser,$sServerPassword);
            if(!$conn) {
                $conn = mysql_connect($sLocalHost,$sLocalUser,$sLocalPassword);
            }
            $db=mysql_select_db($sServerDatabaseName);
            if(!$db){
                $db=mysql_select_db($sLocalDatabaseName);
            }
            // =====basic function liberary============
            class Model
            {
              function find_query_all($pred = '', $params = array(), $select = '*')
              {
                global $db;
                $sql =  $pred;
                $rows = array();
                $rows =$this->getAll($sql, $params);
                $this->_check_error($rows);
                if(count($rows)>0){
                    $this->_row_count=count($rows);
                    }

                else
                    $this->_row_count=0;
                return $rows;
              } 

              //====== fetch  rows  from db and return array of row object
              function getAll($sqlQuery='',$params= array())
              {     
                 $msg="";
                  $this->_sqlQuery="";
                  $sQuery=$this->MakeSQLQuery($sqlQuery,$params);
                  $this->_sqlQuery=$sQuery;
                  $res=mysql_query($sQuery) or die(mysql_error());
                  $results = array();
                  if(mysql_num_rows($res)>0){
                  while ($row = mysql_fetch_object($res)) {
                          $results[] = $row;
                  }
                  }
                  return $results;

              }  

               function MakeSQLQuery($str='',$params= array())
              {
                  foreach($params as $k=>$v){
                   $params[$k]=$this->_quote($params[$k]);
                  }
                  $str=$this->replace_different("?",$params,$str);
                  return $str;
              }

              function replace_different($search,$replace,$string) {
               $occs = substr_count($string,$search);
               $last = 0;
               $cur = 0;
               $data = '';
               for ($i=0;$i<$occs;$i++) {
                 $find = strpos($string,$search,$last);
                 $data .= substr($string,$last,$find-$last).$replace[$cur];
                 $last = $find+strlen($search);
                 if (++$cur == count($replace)) {
                   $cur = 0;
                 }
               }
               return $data.substr($string,$last);
             }

             // check for a database error
              function _check_error($obj, $msg = 'Database Error')
              {

                if (!$this->isError($obj)) 
                  {
                    $this->raise_error($msg . ': ' .$obj->getMessage(). mysql_error());
                  }
                  return ;
              }

              function isError($value)
                {
                    if(isset($value))
                        return true;
                    else
                        return false;
                }

            }
            // main operation from here 
            //====define object of class========
            $tbl_col = new Model;
            $sqlquery_col="SELECT table_name FROM information_schema.tables where table_schema='".$sLocalDatabaseName."'";
            $res_tab_col=$tbl_col->find_query_all($sqlquery_col);
            foreach($res_tab_col as $r=>$v){
                $res=mysql_query("SELECT COLUMN_NAME FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = '".$sLocalDatabaseName."' AND TABLE_NAME ='".$v->table_name."' and COLUMN_NAME!='".$Add_columnname."' ORDER BY ORDINAL_POSITION DESC LIMIT 1");
              if(mysql_num_rows($res)>0){
                 while ($row = mysql_fetch_object($res)) {
                    $last_column= $row->COLUMN_NAME;
                    $alter_query="ALTER TABLE `".$v->table_name."`  ADD `".$Add_columnname."` INT NOT NULL DEFAULT '1' AFTER `".$last_column."` ";
                    mysql_query($alter_query);
                }
              }
            }
    ?>

Answer 4

select concat('alter table ',table_name,' add column ID int auto_increment not null primary key first;')
from information_schema.tables
where table_schema = 'db_name' and table_type = 'base table';

Once you have the output, copy and paste and run them all.