I have a MySQL query that looks like this:
UPDATE `Table` SET `Column` =
CASE
WHEN `Option Id` = '1' THEN 'Apple'
WHEN `Option Id` = '2' THEN 'Banana'
WHEN `Option Id` = '3' THEN 'Q-Tip'
END
An my table currently looks like this:
Option Id | Column
1 | x
2 | x
I'd like it to result in:
Option Id | Column
1 | Apple
2 | Banana
3 | Q-Tip
But it doesn't insert the Q-Tip row. I've looked up and read a bit about INSERT ON DUPLICATE KEY UPDATE
and REPLACE
, but I can't find a way to get those to work with this multiple row update using CASE
. Do I have to write a separate query for each row to get this to work, or is there a nice way to do this in MySQL?
Option Id
is not a Key
itself, but it is part of the Primary Key
.
EDIT Some more info:
I'm programming in PHP, and essentially I'm storing an array for the user. Option Id
is the key, and Column
is the value. So for simplicities sake, my table could look like:
User Id | Option Id | Value
10 | 1 | Apple
10 | 2 | Shoe
11 | 1 | Czar
...
That user can easily update the elements in the array and add new ones, then POST
the array to the server, in which case I'd like to store it in the table. My query above updates any array elements that they've edited, but it doesn't insert the new ones. I'm wondering if there is a query that can take my array from POST
and insert it into the table without me having to write a loop and have a query for every array element.
Of course it does not insert. As there is no such value, it cannot get updated.
I suppose you are normalizing a database by putting in the values already present and now want to add the required mapping for every valid value.
So it would be better to start from scratch and just do INSERTs.
This should work, if Option_Id
is a primary key:
REPLACE INTO `Table` (`Option_Id`, `Column`) VALUES
(1, 'Apple'),
(2, 'Banana'),
(3, 'Q-Tip');
The statement means: Insert the given rows or replace the values, if the PK is already existing.
您总是可以查询数据库中的条目,然后根据您的结果选择更新或插入
I see no point in such updating.
Why don't you have a separate table with option ids and corresponding values, leaving only option ids linked to user ids in this one?
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.