SQL 插入唯一索引
示例
UPDATE Customers SET Email = "richard0123@example.com" WHERE id = 1;
如果在“客户”的“电子邮件”列上设置了唯一索引,则此操作将失败。但是,可以为这种情况定义其他行为:
UPDATE Customers SET Email = "richard0123@example.com" WHERE id = 1 ON DUPLICATE KEY;
UPDATE Customers SET Email = "richard0123@example.com" WHERE id = 1;
如果在“客户”的“电子邮件”列上设置了唯一索引,则此操作将失败。但是,可以为这种情况定义其他行为:
UPDATE Customers SET Email = "richard0123@example.com" WHERE id = 1 ON DUPLICATE KEY;