我有这些table：

Database (databaseId, databaseName, ServerId, NumberOfTables)  
User (userId, userName, numberOfDatabases) 
PermissionAccess (userId, databaseId, permission)

我试图做一个Assert，使numberofdatabases值等于permissionaccess中属于该用户标识的行数。
你喜欢这个工作吗？

CREATE ASSERTION DatabasesNumber
CHECK ( (SELECT numberOfDatabases FROM User U GROUP BY U.userID WHERE numberOfDatabases = (SELECT COUNT (*) FROM PermissionAccess) ) );