如何使用 SQL 中的事務將數據從一個表插入到另一個表？

Question

這是我要插入數據的表

group_id  | customer_id 
-----------------------
3         |  14
3         |  8
4         |  14

插入一個值代碼將是這樣的：

BEGIN TRANSACTION
    INSERT INTO results(group_id INT, customer_id INT)
    VALUES(4, 12)
COMMIT;

插入從復雜的 select 語句中獲得的多個 customer_id 值的正確方法是什么？ 可以這樣做嗎？ 也許最好在本地臨時表中插入數據然后再插入結果表中？

DECLARE @group_insert INT;
SET @group_insert = 5;

BEGIN TRANSACTION
    INSERT INTO results(group_id INT, customer_id INT)
    SELECT @group_insert, customer_id  ---actual select would have more joins and where conditions
    FROM another_table
    WHERE customer_id > 10
COMMIT;

插入后結果表應如下所示：

group_id  | customer_id 
-----------------------
3         |  14
3         |  8
4         |  14
5         |  15
5         |  16
5         |  17

Answer 1

DECLARE @group_insert INT;
SET @group_insert = 5;

BEGIN TRANSACTION
    INSERT INTO results(group_id , customer_id )
    SELECT @group_insert, customer_id  
    FROM another_table
    WHERE customer_id > 10;
COMMIT;

如果你想 select group_insert column from another_table 然后：

BEGIN TRANSACTION
    INSERT INTO results(group_id , customer_id )
    SELECT group_insert, customer_id  
    FROM another_table
    WHERE customer_id > 10;
COMMIT;

Answer 2

我認為您可能過於簡化了，但作為一個猜測，這里有一個不允許在另一個表中重復 cid 的代碼，以及一個計算下一個 id 用於插入和最小 cid 用於輸入重復數據刪除的過程。

DROP TABLE IF EXISTS T,T1;
DROP PROCEDURE IF EXISTS P;

CREATE TABLE T (ID INT,CID INT);
CREATE TABLE T1(CID INT PRIMARY KEY);

DROP PROCEDURE IF EXISTS P;
DELIMITER $$
CREATE PROCEDURE P()
BEGIN
 SELECT COALESCE(MAX(ID),0) + 1 INTO @NEXTID FROM T;
 SET @MAXCID = NULL;
 IF @NEXTID = 1 THEN
    SET @MAXCID = 0;
  ELSE
    SELECT MIN(CID) INTO @MAXCID FROM T1 WHERE NOT EXISTS(SELECT CID FROM T WHERE T.CID = T1.CID);
 END IF;
 
 IF @MAXCID IS NOT NULL THEN
  INSERT INTO T
    SELECT @NEXTID,CID
     FROM T1 
     WHERE CID >= @MAXCID;
 END IF;
 
     
END $$
DELIMITER ;
TRUNCATE TABLE T;
TRUNCATE TABLE T1;

INSERT IGNORE INTO T1 VALUES (1);
CALL P();


INSERT IGNORE INTO T1 VALUES (2),(3);
CALL P();


INSERT IGNORE INTO T1 VALUES (2),(3),(4),(5);
CALL P();

 MariaDB [SANDBOX]> select * from t1;
+-----+
| CID |
+-----+
|   1 |
|   2 |
|   3 |
|   4 |
|   5 |
+-----+
5 rows in set (0.002 sec)

MariaDB [SANDBOX]> select * from t;
+------+------+
| ID   | CID  |
+------+------+
|    1 |    1 |
|    2 |    2 |
|    2 |    3 |
|    3 |    4 |
|    3 |    5 |
+------+------+
5 rows in set (0.001 sec)