mysql> SELECT concat(table_schema,’.',table_name) table_name,
-> concat(round(data_length/(1024*1024),2),’M') data_length
-> FROM information_schema.TABLES
-> ORDER BY abs(data_length) DESC LIMIT 5;

You can go like this :

$link = mysql_connect(‘host’, ‘user’, ‘password’);
mysql_select_db(‘database’, $link);

$sql = ‘select table_name from information_schema.tables where table_schema=”miDB”‘;
$run = mysql_query($sql, $link) or die(mysql_error());

if($run && mysql_num_rows($run) > 0) {
$query = ‘YOUR_QUERY_HERE’;

mysql_select_db(“miDB”, $link);

while(($fetch = mysql_fetch_assoc($run)) !== false) {
$exec = mysql_query($query, $link);

// process your o/p here….
}
}

hope it helps !

Regards,

Pushpesh

You can use the following query to retrieve all the column names for a given database :

SELECT DISTINCT `COLUMN_NAME`
FROM `COLUMNS`
WHERE `TABLE_SCHEMA` = ‘YOUR_DATABASE_NAME_HERE’
AND `TABLE_NAME` = ‘YOUR_TABLE_NAME_HERE’;

hope it helps!

Regards,

Pushpesh

how I can use select table_name from information_schema.tables where table_schema=”miDB” in a query ?

and make same query over every table of mi db?

thanks.

In working with some sophisticated ERPs, (Baan), their sql for retrievals appears like this

select xxxxxxx
from xxxxxxxx
where
xxxxxxx
selectdo
xxxxxxx
selectempty
xxxxxxxx
selecteos
xxxxxxxxx
endselect

The where clause can have other selects (recursive). such as from where exists (select … )
The where clause always did a left join, so the programmer decided if he wanted
where a = b,
or wanted
where b=a

selectdo
loop here until empty
selecteos
after the last match
selectempty
if there is no match
endselect

The from clause indicated if it was for update, etc. A break command and continue are supported in the seledtdo as well as the selecteos.

How difficult is it to develop this set of statements as a pre-parser expression for mysql, or oracle, or postgressql ?