[英]Update mysql database using values from table
我對現有的 mysql 數據庫結構進行了一些更改,並希望使用另一個表中的 id 將舊值更新為表中的新字段。 結構如下:
表格1
+---------+--------+
| sale_id | type |
+---------+--------+
| 110 | credit |
| 111 | cash |
| 112 | credit |
+---------+--------+
表2
+---------+--------+---------+-----------------+---------------+
| sale_id | item_id| price | payment_type | total_amount |
+---------+--------+---------+-----------------+---------------+
| 110 | 1 | 20 | | |
| 111 | 2 | 30 | | |
| 112 | 3 | 45 | | |
| 112 | 4 | 15 | | |
+---------+--------+---------+-----------------+---------------+
現在我想使用 table1 中的 sale_id 作為參考來更新 table2 中的 payment_type 和 total_amount。
table2 更新后的預期結果
+---------+--------+---------+-----------------+---------------+
| sale_id | item_id| price | payment_type | total_amount |
+---------+--------+---------+-----------------+---------------+
| 110 | 1 | 20 | credit | 20 |
| 111 | 2 | 30 | cash | 30 |
| 112 | 3 | 45 | credit | 45 |
| 112 | 4 | 15 | credit | 15 |
+---------+--------+---------+-----------------+---------------+
我當前的嘗試不起作用並引發錯誤。
CREATE TABLE table1(
sale_id INTEGER NOT NULL PRIMARY KEY
,type VARCHAR(6) NOT NULL
);
INSERT INTO table1(sale_id,type) VALUES (110,'Credit');
INSERT INTO table1(sale_id,type) VALUES (111,'Cash');
INSERT INTO table1(sale_id,type) VALUES (112,'Credit');
CREATE TABLE table2(
sales_id INTEGER NOT NULL PRIMARY KEY
,item_id VARCHAR(6) NOT NULL
,price VARCHAR(6) NOT NULL
,payment_type VARCHAR(6) NOT NULL
,total_amount VARCHAR(6) NOT NULL
);
INSERT INTO table2(sales_id,item_id,price,payment_type,total_amount) VALUES (110,1,20,'','');
INSERT INTO table2(sales_id,item_id,price,payment_type,total_amount) VALUES (111,2,30,'','');
INSERT INTO table2(sales_id,item_id,price,payment_type,total_amount) VALUES (112,3,45,'','');
INSERT INTO table2(sales_id,item_id,price,payment_type,total_amount) VALUES (112,4,15,'','');
UPDATE table2 SET total_amount =
(SELECT price
FROM table2
INNER JOIN table1 ON sale_id = sales_id
);
UPDATE table2 SET payment_type =
(SELECT type
FROM table2
INNER JOIN table1 ON sale_id = sales_id
);
這就是更新/加入語法:
update table2 t2
inner join table1 t1 on t1.sale_id = t2.sale_id
set t2.payment_type = t1.type, t2.total_amount = t2.price
您可以使用更新子句更新表
UPDATE table2
INNER JOIN table1
ON table2.sale_id = table1.sale_id
SET table2.payment_type = table1.type
table2.total_amount = table2.price ;
有關更新加入的更多實踐,請點擊以下鏈接
我認為您嘗試使用錯誤的方法。 取而代之的是規范化數據並使用 JOIN 來反規范化數據。 我建議對 sales 和 sale_items 使用不同的表,但可以按需從兩個表中獲取數據,例如:
CREATE TABLE payment_types (
id INTEGER NOT NULL PRIMARY KEY
,type VARCHAR(6) NOT NULL
);
INSERT INTO payment_types VALUES (1,'Credit'), (2,'Cash');
CREATE TABLE sales (
id INTEGER NOT NULL PRIMARY KEY
,payment_type_id INTEGER NOT NULL
);
INSERT INTO sales(id,payment_type_id) VALUES (110,1), (111,2), (112,1);
CREATE TABLE sale_items (
sale_id INTEGER NOT NULL
,item_id INTEGER NOT NULL
,price INTEGER NOT NULL
,quantity INTEGER NOT NULL
);
INSERT INTO sale_items (sale_id,item_id,price,quantity) VALUES
(110,1,20,1), (111,2,30,2), (112,3,45,1), (112,4,15,1);
select
sale_id,
pt.type,
si.*,
price * quantity as total_amount
from sales s
join payment_types pt on pt.id = s.payment_type_id
join sale_items si on si.sale_id = s.id;
+=========+========+=========+=======+==========+==============+
| sale_id | type | item_id | price | quantity | total_amount |
+=========+========+=========+=======+==========+==============+
| 110 | Credit | 1 | 20 | 1 | 20 |
+---------+--------+---------+-------+----------+--------------+
| 111 | Cash | 2 | 30 | 2 | 60 |
+---------+--------+---------+-------+----------+--------------+
| 112 | Credit | 3 | 45 | 1 | 45 |
+---------+--------+---------+-------+----------+--------------+
| 112 | Credit | 4 | 15 | 1 | 15 |
+---------+--------+---------+-------+----------+--------------+
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