Question

我要说这3张桌子。

CREATE TABLE IF NOT EXISTS GROUP ( 
           ID_GROUP INT(11) NOT NULL AUTO_INCREMENT PRIMARY KEY, 
           GROUP VARCHAR(50) NOT NULL, 
           INDEX(GROUP) 
         ) ENGINE=INNODB DEFAULT CHARACTER SET = utf8 COLLATE = utf8_general_ci;)

CREATE TABLE IF NOT EXISTS USERZ (
            ID CHAR(8) NOT NULL, 
            GROUP VARCHAR(50) NOT NULL, 
            FIRST_NAME VARCHAR(100) NULL DEFAULT NULL , 
            LAST_NAME VARCHAR(100) NULL DEFAULT NULL, 
            DATE_CREATED TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP, 
            PASSWORD VARCHAR(8) NULL DEFAULT 'HELLOWORLD', 
            PRIMARY KEY (ID), 
            INDEX (ID), 
            INDEX (GROUP), 
            FOREIGN KEY (GROUP) REFERENCES GROUP (GROUP) 
    ) ENGINE=INNODB DEFAULT CHARACTER SET = utf8 COLLATE = utf8_general_ci;)


CREATE TABLE IF NOT EXISTS WORKERS (   
          ID CHAR(8) NOT NULL PRIMARY KEY,   
          DATE_START TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,   
          DATE_END TIMESTAMP NULL,   
          FOREIGN KEY (ID) REFERENCES USERZ (ID)   
) ENGINE=INNODB DEFAULT CHARACTER SET = utf8 COLLATE = utf8_general_ci;)

我在表USERZ中插入数据没有问题。但是当要在表WORKERS中添加记录时，我收到错误消息：

mysql.connector.errors.IntegrityError：1452（23000）：无法添加或更新子行：外键约束失败（DATABASENAME。WORKERS，CONSTRAINT WORKERS_ibfk_1 FOREIGN KEY （ID）参考USERZ（ID））

我确信这是WORKERS主键（ID）指的是USERZ（ID）。即使我知道USERZ中存在USERZ ID，它也不会让我向WORKERS添加数据。以下为例，我知道＆＃39; XXXXXXX1＆＃39;存在于USERZ表中，因此我假设能够在WORKERS表中添加此用户。

例如

：

"INSERT INTO WORKERS (ID) VALUES ('XXXXXXX1') "

谢谢！

Answer 1

你不应该将主键id作为外键。重构它就像这样

CREATE TABLE IF NOT EXISTS WORKERS (   
          ID CHAR(8) NOT NULL PRIMARY KEY, 
          USER_ID CHAR(8) NOT NULL,
          DATE_START TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,   
          DATE_END TIMESTAMP NULL,   
          FOREIGN KEY (USER_ID) REFERENCES USERZ (ID)   
) ENGINE=INNODB DEFAULT CHARACTER SET = utf8 COLLATE = utf8_general_ci;)

然后你的插入应该是

INSERT INTO WORKERS (USER_ID) VALUES ('XXXXXXX1')

MySQL主键作为外键 - 约束错误

1 个答案: