私は基本的にデータのバッファとして使用しているので、ENGINER = MEMORYを使用している小さな3テーブルデータベースを作成しています。データベースには、以下の構造を有する:CASCADE mysqlを削除
私の質問があるので、私は、MySQLのにそれほどないよ:それはCASCADE DELETEを持つことが可能であり、そのような私はMeassurementIterationを削除し、すべてのMeassurementSet年代ということと、反復に結合された消耗品は削除されますか?
コード:
-- Last modification date: 2017-04-03 08:09:06.263
-- tables
-- Table: Meassurement
CREATE TABLE Meassurement (
id int NOT NULL AUTO_INCREMENT,
msWay varchar(75) NOT NULL,
qosClass int NOT NULL,
timeReceived timestamp NOT NULL,
timeReceivedFarEnd timestamp NOT NULL,
timeSent timestamp NOT NULL,
timeSentFarEnd timestamp NULL,
seq int NOT NULL,
MeassurementSet_id int NOT NULL,
CONSTRAINT Meassurement_pk PRIMARY KEY (id)
) ENGINE MEMORY COMMENT 'Contains data for a single meassurement';
-- Table: MeassurementIteration
CREATE TABLE MeassurementIteration (
id int NOT NULL AUTO_INCREMENT,
start timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
end timestamp NULL,
active bool NOT NULL,
CONSTRAINT MeassurementIteration_pk PRIMARY KEY (id)
);
-- Table: MeassurementSet
CREATE TABLE MeassurementSet (
id int NOT NULL AUTO_INCREMENT,
avgDelayRT double NULL,
avgDelayTR double NULL,
avgRTD double NULL,
maxDelayRT double NULL,
maxDelayTR double NULL,
maxRTD double NULL,
minRTD double NULL,
minDelayRT double NULL,
minDelayTR double NULL,
qosClass int NOT NULL,
stdDev double NULL,
stdDevRT double NULL,
stdDevTR double NULL,
msWay varchar(75) NOT NULL,
MeassurementIteration_id int NOT NULL,
CONSTRAINT MeassurementSet_pk PRIMARY KEY (id)
) ENGINE MEMORY COMMENT 'Contains a set of meassurements specific to a qosclass and Meassurementway';
-- foreign keys
-- Reference: MeassurementSet_MeassurementIteration (table: MeassurementSet)
ALTER TABLE MeassurementSet
ADD CONSTRAINT MeassurementSet_MeassurementIteration
FOREIGN KEY MeassurementSet_MeassurementIteration (MeassurementIteration_id)
REFERENCES MeassurementIteration (id) ON DELETE CASCADE;
-- Reference: Meassurement_MeassurementSet (table: Meassurement)
ALTER TABLE Meassurement
ADD CONSTRAINT Meassurement_MeassurementSet
FOREIGN KEY Meassurement_MeassurementSet (MeassurementSet_id)
REFERENCES MeassurementSet (id) ON DELETE CASCADE;
-- End of file.
よろしく。
http://www.mysqltutorial.org/mysql- REFERENTIAL_CONSTRAINTS FROM on-delete-cascade / – scaisEdge