Question

我有一个简单的插入选择，在 _TABLE_A _ 新行中插入 _TABLE_B _ 数据

INSERT INTO _TABLE_A_(_USERNAME_,_ID_) 
SELECT  _USERNAME_,_ID_ 
FROM _TABLE_B_

每次在 _TABLE_A _中插入一行时，我想在名为 _TABLE_C _ 的表格中插入一行，并添加当前插入的 _TABLE_C _ ID为 _TABLE_A _ 。

我会试着以另一种方式解释它：

INSERT INTO _TABLE_A_(_USERNAME_,_ID_,_FOREIGN_ID_) 
SELECT  B._USERNAME_,B._ID_,C._FOREIGN_ID_
FROM _TABLE_B_ AS B 
LEFT JOIN _TABLE_C_ AS C
#Insert a row in _TABLE_C_ to retrieve _FOREIGN_ID_...

我正在搜索一个像我这样的 INSERT SELECT 语句的单个最小查询，因为insert select可以循环，我必须循环。

仅供参考：我在存储过程中。我还使用带有动态数据的预处理语句，而游标不适合动态数据选择...

Answer 1

我会首先在_TABLE_C_中执行所有INSERT，然后将其加入INSERT _TABLE_A_以获取相应的外键。

如果那是不可能的，我会使用光标。

Cursor on _TABLE_B_ & Fetch

INSERT _TABLE_C_

INSERT _TABLE_A_ with Foreign_Id = SCOPE_IDENTITY()

Fetch next

Answer 2

我找到了解决方案。

创建一个临时表并添加动态select语句，以检索主键（id）
声明游标并选择此临时表id（变量不起作用，但临时表可以）
执行语句以创建临时表
打开游标并迭代插入

实施例

  BEGIN


    DECLARE isDone INT DEFAULT 0;
    DECLARE fetchedmemberWhoWillReceiveMailId int;

    DECLARE cur1 CURSOR FOR SELECT id FROM memberWhoWillReceiveMail;
    DECLARE CONTINUE HANDLER FOR SQLSTATE '02000' SET isDone = 1;
    SET SESSION TRANSACTION ISOLATION LEVEL SERIALIZABLE;

    SET @sexe     = VAR_sexe; 
    SET @event    = VAR_eventId;
    SET @subject = VAR_subject;
    SET @body     = VAR_body; 
    SET @to        = VAR_to; 
    SET @from  = VAR_from;
    SET @region    = VAR_region;
    SET @departement      = VAR_departement; 
    SET @age        = VAR_age;

    SET @baseSqlStatement =' CREATE TEMPORARY TABLE memberWhoWillReceiveMail SELECT e.id FROM TABLE_A as e LEFT JOIN TABLE_B AS a on a.member_id = e.id';

    SET @whereSqlStatement= 'WHERE e.is_visible = 1 AND e.member_group_id IN (10,11) ';

    IF (@region!='') THEN  
    SET @whereSqlStatement=  CONCAT(@whereSqlStatement,' AND region=',@region);
    END IF;

    IF (@event !=null ) THEN 
    SET @whereSqlStatement=  CONCAT(@whereSqlStatement,' AND m.event_id !=' ,@eventId); 
    END IF;

    IF (@sexe!=null ) THEN
    SET @whereSqlStatement=  CONCAT(@whereSqlStatement,' AND e.sexe=',@sexe); 
    END IF;

    SET @baseSqlStatement = CONCAT(@baseSqlStatement,@whereSqlStatement);

    START TRANSACTION;
    PREPARE stmt1 FROM @baseSqlStatement;
    EXECUTE stmt1; 
    DEALLOCATE PREPARE stmt1;

    OPEN cur1; 
    FETCH cur1 INTO fetchedmemberWhoWillReceiveMailId; 
    WHILE NOT isDone DO
        INSERT INTO conversation(created_at,updated_at)VALUES(now(),now());
        INSERT INTO message(created_at,updated_at,from, to, uniqueID)   VALUES(now(),now(),@from,fetchedmemberWhoWillReceiveMailId,LAST_INSERT_ID() );
        FETCH cur1 INTO fetchedmemberWhoWillReceiveMailId; END WHILE; CLOSE cur1;

    COMMIT;
    DROP TEMPORARY TABLE IF EXISTS memberWhoWillReceiveMail;

    END

如何在mysql的insert命令中插入？

2 个答案: