Question

我有一个表distributor_warehouse，表中有一个自动递增的dpID。我在插入第一行后无法插入行。我曾经看到过类似的查询，但是到处都可以看到该列需要自动递增的答案，这已经在我的系统中完成了。

mysql> desc distributor_warehouse;
+------------+---------------+------+-----+---------+-------+
| Field      | Type          | Null | Key | Default | Extra |
+------------+---------------+------+-----+---------+-------+
| dpID       | varchar(12)   | NO   | PRI |         |       |
| cpID       | varchar(12)   | YES  |     | NULL    |       |
| QTY        | int(6)        | YES  |     | NULL    |       |
| COST_PRICE | decimal(10,2) | YES  |     | NULL    |       |
| SELL_PRICE | decimal(10,2) | YES  |     | NULL    |       |
+------------+---------------+------+-----+---------+-------+
5 rows in set (0.01 sec)

mysql> select * from distributor_warehouse;
+------+------+------+------------+------------+
| dpID | cpID | QTY  | COST_PRICE | SELL_PRICE |
+------+------+------+------------+------------+
| DP1  | CP5  |   10 |    3000.00 |    3100.00 |
+------+------+------+------------+------------+
1 row in set (0.00 sec)

mysql> INSERT INTO distributor_warehouse(cpID,QTY,COST_PRICE,SELL_PRICE) VALUES ('CP6',150,999,1500);
ERROR 1062 (23000): Duplicate entry 'DP1' for key 'PRIMARY'

dpID通过使用触发器自动增加。

这是我的桌子。我已经成功插入第1行，然后在插入第2行时就出现了问题。

mysql> desc autoid;
+-------+---------+------+-----+---------+----------------+
| Field | Type    | Null | Key | Default | Extra          |
+-------+---------+------+-----+---------+----------------+
| ID    | int(10) | NO   | PRI | NULL    | auto_increment |
+-------+---------+------+-----+---------+----------------+
1 row in set (0.00 sec)

| tg_distributor_warehouse_id | INSERT | distributor_warehouse | BEGIN
INSERT INTO autoid VALUES(NULL);
SET NEW.dpID = CONCAT('DP',LPAD(LAST_INSERT_ID(),1,''));
END |

Answer 1

您的代码似乎不错

drop table if exists t,t1;
create table t(dpid varchar(12), cpid varchar(12), qty int,cost_price decimal(10,2),sell_price decimal(10,2));
create table t1(id int auto_increment primary key);

drop trigger if exists t;
delimiter$$
create trigger t before insert on t
for each row
begin
    insert into t1 values (null);
    SET NEW.dpID = CONCAT('DP',LPAD(LAST_INSERT_ID(),1,''));
end$$
delimiter;

INSERT INTO t(cpID,QTY,COST_PRICE,SELL_PRICE) VALUES ('CP6',150,999,1500);


INSERT INTO t(cpID,QTY,COST_PRICE,SELL_PRICE) VALUES ('CP6',150,999,1500);
select * from t;

+------+------+------+------------+------------+
| dpid | cpid | qty  | cost_price | sell_price |
+------+------+------+------------+------------+
| DP1  | CP6  |  150 |     999.00 |    1500.00 |
| DP2  | CP6  |  150 |     999.00 |    1500.00 |
+------+------+------+------------+------------+
2 rows in set (0.00 sec)

错误1062（23000）：键“ PRIMARY”的条目“ DP1”重复

1 个答案: