MySQL: How to sync on demand beetwen two database in the same server

I can see mysqldump being a little pain in the neck because of transaporting data out and then in.

Let's say you are copying data from proddb to stagedb. Here is a query to create the script for lateral copying of every table:

select
concat
(
    'drop table if exists ',db2,'.',tbl,'; ',
    'create table ',db2,'.',tbl,' like ',db1,'.',tbl,'; ',
    'insert into  ',db2,'.',tbl,' select * from ',db1,'.',tbl,';'
)
from (select table_schema db1,table_name tbl
from information_schema.tables where table_schema='stack_dev') tbls,
(select 'stack_test' db2) dbname;

Just generate the script as a SQL text file and import the text file to the target server:

PROD_IP-10.1.2.20
STAG_IP=10.1.2.40
mysql -h${PROD_IP} -uusername -p --skip-column-names -A -e"select concat('drop table if exists ',db2,'.',tbl,'; ','create table ',db2,'.',tbl,' like ',db1,'.',tbl,'; ','insert into  ',db2,'.',tbl,' select * from ',db1,'.',tbl,';') from (select table_schema db1,table_name tbl from information_schema.tables where table_schema='stack_dev') tbls,(select 'stack_test' db2) dbname;" > /root/CopyFromProdToStage.sql
mysql -h${STAG_IP} -uusername -p -A < /root/CopyFromProdToStage.sql

This should work just fine for MyISAM. It should also work for InnoDB if there are no constraints. If there are constraints, you may have to disable them for the import session:

PROD_IP-10.1.2.20
STAG_IP=10.1.2.40
echo "SET FOREIGN_KEY_CHECKS=0;" > /root/CopyFromProdToStage.sql
mysql -h${PROD_IP} -uusername -p --skip-column-names -A -e"select concat('drop table if exists ',db2,'.',tbl,'; ','create table ',db2,'.',tbl,' like ',db1,'.',tbl,'; ','insert into  ',db2,'.',tbl,' select * from ',db1,'.',tbl,';') from (select table_schema db1,table_name tbl from information_schema.tables where table_schema='stack_dev') tbls,(select 'stack_test' db2) dbname;" >> /root/CopyFromProdToStage.sql
mysql -h${STAG_IP} -uusername -p -A < /root/CopyFromProdToStage.sql

UPDATE 2012-03-09 17:14 EST

I have a stored procedure that will accomplish this. Run the following only once:

DROP DATABASE IF EXISTS utility;
CREATE DATABASE utility;
DELIMITER $$
DROP PROCEDURE IF EXISTS `utility`.`CopyDB` $$
CREATE PROCEDURE `utility`.`CopyDB` (sourceDB VARCHAR(64),targetDB VARCHAR(64))
TheStoredProcedure:BEGIN

    DECLARE found_count,ndx,ndx_last INT;
    DECLARE sqlcmd VARCHAR(1024);

    SELECT COUNT(1) INTO found_count
    FROM information_schema.tables
    WHERE table_schema = sourceDB;
    IF found_count = 0 THEN
        LEAVE TheStoredProcedure;
    END IF;

    DROP TABLE IF EXISTS DBTablesToCopy;
    CREATE TABLE DBTablesToCopy
    (
        id INT NOT NULL AUTO_INCREMENT,
        src  VARCHAR(64),
        tgt  VARCHAR(64),
        tbl  VARCHAR(64),
        PRIMARY KEY (id)
    ) ENGINE=MyISAM;
    DROP TABLE IF EXISTS SQLScriptToCopyTables;
    CREATE TABLE SQLScriptToCopyTables
    (
        id INT NOT NULL AUTO_INCREMENT,
        sqltext VARCHAR(1024),
        PRIMARY KEY (id)
    ) ENGINE=MyISAM;

    INSERT INTO DBTablesToCopy (src,tgt,tbl)
    SELECT sourceDB,targetDB,table_name
    FROM information_schema.tables
    WHERE table_schema = sourceDB;

    INSERT INTO SQLScriptToCopyTables (sqltext) VALUES
    (CONCAT('DROP DATABASE IF EXISTS ',targetDB));
    INSERT INTO SQLScriptToCopyTables (sqltext) VALUES
    (CONCAT('CREATE DATABASE ',targetDB));
    SELECT MAX(id) INTO ndx_last FROM DBTablesToCopy;
    SET ndx = 0;
    WHILE ndx < ndx_last DO
        SET ndx = ndx + 1;
        INSERT INTO SQLScriptToCopyTables (sqltext)
        SELECT CONCAT('CREATE TABLE ',tgt,'.',tbl,' LIKE ',src,'.',tbl)
        FROM DBTablesToCopy WHERE id = ndx;
    END WHILE;
    SET ndx = 0;
    WHILE ndx < ndx_last DO
        SET ndx = ndx + 1;
        INSERT INTO SQLScriptToCopyTables (sqltext)
        SELECT CONCAT('INSERT INTO ',tgt,'.',tbl,' SELECT * FROM ',src,'.',tbl)
        FROM DBTablesToCopy WHERE id = ndx;
    END WHILE;

    SELECT MAX(id) INTO ndx_last FROM SQLScriptToCopyTables;
    SET ndx = 0;
    WHILE ndx < ndx_last DO
        SET ndx = ndx + 1;
        SELECT sqltext INTO @stmt FROM SQLScriptToCopyTables WHERE id = ndx;
        PREPARE s1 FROM @stmt;
        EXECUTE s1;
        DEALLOCATE PREPARE s1;
    END WHILE;

END $$
DELIMITER ;

then anytime you feel like copying stack_dev to stack_test, do this:

call utility.copydb('stack_dev','stack_test');

and that's all.

Give it a Try !!!

Users on MySQL are sharing the same context in terms of databases. So if you are creating a database for one user, it will be also visible to user2.

You could solve this issue by prefixing your tables for each user, e.g. abc_item1 and setting correct privileges via grant for it -- so only one user is allowed to use this table.

Another way would be to just create different databases for each user -- which is I think the MySQL way of doing such things.