Question

我有以下声明：

INSERT INTO `Properties`(`Id`, `Url`, `BrokerId`, `LastFound`) VALUES
(@Id,@Url,@BrokerId,@LastFound)
ON DUPLICATE KEY UPDATE LastFoundOn = @LastFoundOn;

INSERT INTO `Events`(`Id`, `Type`, `DateTime`, `PropertyId`) VALUES
(@EventId,@EventType,@Now,@Id);

Properties.Id和Events.PropertyId之间存在外键约束。而网址是独一无二的。

这很有效 - 差不多。如果未插入recod，但由于重复键（Url）而更新，则insert into event将失败，因为外键根本不存在。像这样：

例如：

exists:    1  |  http://test1.com  |  2  |  2013-03-13
to insert: 2  |  http://test2.com  |  2  |  2013-03-14

尝试插入时，由于唯一的网址，它会更新。之后尝试插入事件时，“属性”表中不存在外键（2）。如何制作if then语句来处理这种情况？

像（？）：

INSERT INTO `Properties`(`Id`, `Url`, `BrokerId`, `LastFound`) VALUES
(@Id,@Url,@BrokerId,@LastFound)
ON DUPLICATE KEY UPDATE LastFoundOn = @LastFoundOn;
IF LastInserted = @Id THEN
INSERT INTO `Events`(`Id`, `Type`, `DateTime`, `PropertyId`) VALUES
(@EventId,@EventType,@Now,@Id);
END IF;

更新：

触发器可能是解决方案，但我正在努力使它成功。这有什么不对？

DELIMITER $$
CREATE TRIGGER Event_Submitted_Trigger AFTER INSERT ON Properties 
FOR EACH ROW
BEGIN
INSERT INTO Events VALUES(SELECT(UUID()), 'PropertySubmitted', SELECT(NOW()), new.Id);
END$$

我收到以下错误：＃1064 - 您的SQL语法出错;检查与MySQL服务器版本对应的手册，以便在'SELECT（NOW（）），new.Id）附近使用正确的语法; END $$'在第4行

致以最诚挚的问候，

索伦

更新：

这是我的架构：

CREATE TABLE IF NOT EXISTS `Events` (
  `Id` char(36) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL,
  `Type` enum('PropertySubmitted','PropertyChanged','PropertyRemoved') NOT NULL,
  `DateTime` datetime NOT NULL,
  `Attribute` varchar(128) NOT NULL,
  `From` varchar(512) NOT NULL,
  `To` varchar(512) NOT NULL,
  `PropertyId` char(36) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL,
  PRIMARY KEY (`Id`),
  KEY `IX_FK_PropertyEvent` (`PropertyId`),
  KEY `DateTimeIndex` (`DateTime`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

-- --------------------------------------------------------

--
-- Table structure for table `Properties`
--

CREATE TABLE IF NOT EXISTS `Properties` (
  `Id` char(36) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL,
  `Url` varchar(255) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL,
  `Type` varchar(64) NOT NULL,
  `ExtractedAddress` varchar(192) NOT NULL,
  `ExtractedPostcode` varchar(8) NOT NULL,
  `ExtractedCity` varchar(64) NOT NULL,
  `StreetName` varchar(128) DEFAULT NULL,
  `StreetNumber` varchar(8) DEFAULT NULL,
  `Floor` varchar(8) DEFAULT NULL,
  `Side` varchar(8) DEFAULT NULL,
  `DoorNo` varchar(8) DEFAULT NULL,
  `Postcode` int(4) DEFAULT NULL,
  `City` varchar(64) DEFAULT NULL,
  `Latitude` double DEFAULT NULL,
  `Longitude` double DEFAULT NULL,
  `ImageUrl` varchar(512) CHARACTER SET utf8 COLLATE utf8_bin DEFAULT NULL,
  `Price` int(8) NOT NULL,
  `Payout` int(8) NOT NULL,
  `GrossPrice` int(6) NOT NULL,
  `NetPrice` int(6) NOT NULL,
  `Area` int(5) NOT NULL,
  `GroundArea` int(5) NOT NULL,
  `Rooms` int(2) NOT NULL,
  `Year` int(4) NOT NULL,
  `PriceChange` int(11) NOT NULL,
  `FirstFoundOn` datetime NOT NULL,
  `SubmittedOn` datetime NOT NULL,
  `LastFoundOn` datetime NOT NULL,
  `FoundAt` varchar(256) DEFAULT NULL,
  `Validated` tinyint(1) NOT NULL,
  `BrokerId` char(36) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL,
  `Archived` tinyint(1) NOT NULL DEFAULT '0',
  PRIMARY KEY (`Id`),
  UNIQUE KEY `Url` (`Url`),
  KEY `IX_FK_PropertyBroker` (`BrokerId`),
  KEY `UrlIndex` (`Url`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

--
-- Triggers `Properties`
--
DROP TRIGGER IF EXISTS `Event_Submitted_Trigger`;
DELIMITER //
CREATE TRIGGER `Event_Submitted_Trigger` AFTER INSERT ON `Properties`
 FOR EACH ROW BEGIN
 INSERT INTO `Events` VALUES(UUID(), 'PropertySubmitted', NOW(), NEW.Id);
END
//
DELIMITER ;

--
-- Constraints for dumped tables
--

--
-- Constraints for table `Events`
--
ALTER TABLE `Events`
  ADD CONSTRAINT `Events_ibfk_1` FOREIGN KEY (`PropertyId`) REFERENCES `Properties` (`Id`) ON DELETE CASCADE ON UPDATE CASCADE;

--
-- Constraints for table `Properties`
--
ALTER TABLE `Properties`
  ADD CONSTRAINT `Properties_ibfk_2` FOREIGN KEY (`BrokerId`) REFERENCES `Brokers` (`Id`) ON DELETE NO ACTION ON UPDATE NO ACTION;

Answer 1

假设以下结构：

CREATE TABLE Properties (
    id         INT,
    url        VARCHAR(100),
    lastFound  DATETIME,
    UNIQUE (url)
) ;

CREATE TABLE Events (
    id         VARCHAR(36),
    type       VARCHAR(20),
    t          DATETIME,
    propertyId INT
) ;

这是一个有效的触发器：

DELIMITER $$
CREATE TRIGGER Event_Submitted_Trigger AFTER INSERT ON Properties 
FOR EACH ROW BEGIN
    INSERT INTO Events VALUES( UUID(), 'PropertySubmitted', NOW(), new.Id);
END $$
DELIMITER ;

在行动here中查看。注意NOW()+SLEEP(1) hack，只是为了延迟执行以获得重要结果（SLEEP()如果没有中断则返回0）。

Mysql语句插入，如果插入，则插入另一个

1 个答案: