@george1421
Thank you very much for your help!
For information, i ran the next command succesfully:
DELETE FROM `hosts` WHERE `hostID` = '0';
DELETE FROM `hostMAC` WHERE hmID = '0' OR `hmHostID` = '0';
DELETE FROM `groupMembers` WHERE `gmID` = '0' OR `gmHostID` = '0' OR `gmGroupID` = '0';
DELETE FROM `snapinGroupAssoc` WHERE `sgaID` = '0' OR `sgaSnapinID` = '0' OR `sgaStorageGroupID` = '0';
DELETE from `snapinAssoc` WHERE `saID` = '0' OR `saHostID` = '0' OR `saSnapinID` = '0';
DELETE FROM `hosts` WHERE `hostID` NOT IN (SELECT `hmHostID` FROM `hostMAC` WHERE `hmPrimary` = '1');
DELETE FROM `hosts` WHERE `hostID` NOT IN (SELECT `hmHostID` FROM `hostMAC`);
DELETE FROM `hostMAC` WHERE `hmhostID` NOT IN (SELECT `hostID` FROM `hosts`);
DELETE FROM `snapinAssoc` WHERE `saHostID` NOT IN (SELECT `hostID` FROM `hosts`);
DELETE FROM `groupMembers` WHERE `gmHostID` NOT IN (SELECT `hostID` FROM `hosts`);
DELETE FROM `tasks` WHERE `taskStateID` IN ("1","2","3");
DELETE FROM `snapinTasks` WHERE `stState` in ("1","2","3");
TRUNCATE TABLE multicastSessions;
TRUNCATE TABLE multicastSessionsAssoc;
DELETE FROM tasks WHERE taskTypeId=8;
But the problem remains…