Question

这很直接，但我找不到答案。如果组合确实存在，则UPDATE，否则INSERT。

IF EXISTS(SELECT customer_id FROM payment_conditions WHERE customer_id = 2 AND shipping_company_id = 1) 

THEN
UPDATE payment_conditions SET payment_condition = "pay in full" WHERE customer_id = 2  AND shipping_company_id = 1;

ELSE
INSERT INTO payment_conditions customer_id, shipping_company_id, payment_condition, active VALUES (2,1,"some value",1);


END IF

Answer 1

如果你有一个唯一的密钥（shipping_company_id，customer_id），你可以使用：

INSERT INTO payment_conditions 
SET customer_id = 2,
  shipping_company_id = 1,
  payment_condition = 'some value',
  active = 1
ON DUPLICATE KEY UPDATE payment_condition = 'pay in full'

Answer 2

您应该将customer_id和shipping_company_id设置为外键，以便您可以使用

INSERT INTO payment_conditions
    customer_id, shipping_company_id, payment_condition, active
VALUES (2, 1, "some value", 1)
ON DUPLICATE KEY UPDATE payment_condition = "pay in full"

Answer 3

INSERT INTO payment_conditions (customer_id, shipping_company_id, payment_condition, active) 
VALUES (2,1,"some value",1)
ON DUPLICATE KEY UPDATE payment_condition = "pay in full"

Answer 4

或发出两个语句（N.B.，UPDATE优先），并取消条件逻辑。如果行不存在，UPDATE将不起作用。如果您的密钥恰好与customer_id + shipping_company不同，那么这应该有用。

UPDATE payment_conditions SET payment_condition = "pay in full" 
WHERE customer_id = 2  AND shipping_company_id = 1;

然后

INSERT INTO payment_conditions 
(customer_id
, shipping_company_id
, payment_condition
, active) 
VALUES (2,1,"some value",1)
where not exists 
(select * FROM payment_conditions 
   WHERE customer_id = 2 AND shipping_company_id = 1);

Answer 5

在SQL Server中使用merge语句 - 看起来这些答案意味着MySQL语法。您没有说明数据库的味道，但是在SQL Server上建议使用Merge。

如果存在那么

5 个答案: