我在用户和组之间有多对多的关系:
CREATE TABLE IF NOT EXISTS `SecurityIdentifiers` (
`Guid` char(36) NOT NULL,
PRIMARY KEY (`Guid`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
CREATE TABLE IF NOT EXISTS `CaseIdUsers` (
`Sid` char(36) NOT NULL,
`Acl` int(11) NOT NULL,
`FirstName` varchar(45) NOT NULL,
`LastName` varchar(45) NOT NULL,
`CaseID` varchar(8) NOT NULL,
PRIMARY KEY (`Sid`),
UNIQUE KEY `CaseID_UNIQUE` (`CaseID`),
KEY `fk_CaseIDUsers_AccessControlLists1` (`Acl`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
CREATE TABLE IF NOT EXISTS `GroupMembers` (
`User` char(36) NOT NULL,
`Group` char(36) NOT NULL,
PRIMARY KEY (`User`,`Group`),
KEY `fk_Groups_has_SecurityIdentifiers_SecurityIdentifiers1` (`User`),
KEY `fk_Groups_has_SecurityIdentifiers_Groups1` (`Group`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
CREATE TABLE IF NOT EXISTS `Groups` (
`Sid` char(36) NOT NULL,
`Acl` int(11) NOT NULL,
`Name` varchar(45) NOT NULL,
`Description` varchar(255) NOT NULL,
PRIMARY KEY (`Sid`),
UNIQUE KEY `Name_UNIQUE` (`Name`),
KEY `fk_Groups_Access Control Lists1` (`Acl`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
我需要找到所有不在特定组中的用户。我想做类似的事情:
SELECT CaseId FROM CaseIdUsers
EXCEPT
SELECT CaseId FROM CaseIdUsers
JOIN GroupMembers ON GroupMembers.User = CaseIdUsers.Sid
JOIN Groups ON GroupMembers.Group = Groups.Sid
WHERE Groups.Name = 'MyGroupName'
但是 MySQL 不支持EXCEPT
. 现在我该怎么做?