如何在 mySQL Workbench 上添加完整性检查

为此，您必须为车间设置正确数量的位置。 而且你应该有一个程序，减少操作的数量，这样你就可以在一个车间进入新的操作

create table Workshop 
(LOCATIOn Text,numPlaces int,numOperations int
)

INSERT INTO Workshop VALUES ('A',9,8)

create table Operation (idoperation int,workLOCATIOn Text)

CREATE trigGER before_Operation_insert
BEFORE INSERT
ON Operation FOR EACH ROW
BEGIN
    DECLARE Placescount_ INT;
    DECLARE Operationscount_ INT;
    
    SELECT numPlaces,numOperations
    INTO Placescount_,Operationscount_
    FROM Workshop WHERE LOCATIOn = NEW.workLOCATIOn;
    
    IF Placescount_ < Operationscount_ THEN
        updatE Workshop
        SET numOperations = numOperations + 1  WHERE LOCATIOn=new.workLOCATIOn ;
    ELSE
        SIGNAL SQLSTATE '45000'
      SET messaGE_TEXT = 'Maximum number of Operarations reached in LOCATIOn ';
    END IF; 

END

INSERT INTO Operation VALUES (1,'A')

dbfiddle here