Comments on: MySQL UPDATE with SELECT on the same table in the same query

By: WebDev

WebDev — Sat, 14 May 2011 17:18:15 +0000

Thanks a lot! UPDATE queries are pretty obscure and poorly documented.

By: Prodis a.k.a. Fernando Hamasaki de Amorim

Prodis a.k.a. Fernando Hamasaki de Amorim — Sun, 20 Mar 2011 11:09:42 +0000

I’ve had the same problem:
#1093 – You can’t specify target table ‘my_table’ for update in FROM clause

So, my first solution has been with variables (like zag):
SELECT @next_value := MAX(some_value) + 1 FROM my_table;
UPDATE my_table SET some_value = @next_value WHERE id = 123;

Now I’m using your solution with Bruno’s simplified approach.

Thanks everybody.

By: zag

zag — Thu, 07 Oct 2010 00:28:40 +0000

I had the same problem and I solved it by used variables:

select @a:= select MAX( some_value ) from my_table;
UPDATE my_table SET some_value = ( @a + 1 ) WHERE id = 123;

By: gopi

gopi — Tue, 14 Sep 2010 23:31:19 +0000

Guys, I too have been breaking my head on this err… thanks for Bruno’s hint. I followed his ‘aliasing’ approach to build a complex query to update moving averages of quantity.
Thanks Bruno !

I had a simple table t, with cols ‘dt’ for date and ‘qty’ for quantity. Here is how i built step by step:

step 1: //start with outline t5 is some random alias

update t tmp () set tmp.mavg = t5.mavg where tmp.dt=t5.date;

step 2: //added t5 alias definition, which shud have mavg and date members.

update t tmp ( ()as t5) set tmp.mavg = t5.mavg where tmp.dt=t5.date;

step 3: mavg and date aliases defined. new aliases t1 & t2 are create to calculate moving average.

update t tmp ( ( select t1.dt as date, avg(t2.qty) as mavg …)as t5) set tmp.mavg = t5.mavg where tmp.dt=t5.date;

final touch:

update t tmp, ((select t1.dt as date, avg(t2.qty) as mavg from t t1, t t2
where t1.dt >=’2007-01-04′ AND t1.dt BETWEEN t2.dt AND t2.dt+4
group by t1.dt order by t1.dt
) as t5) set tmp.mavg = t5.mavg where tmp.dt=t5.date;

yuppie…it worked !

hope this approach will solve someones headache too !

By: did not work

did not work — Fri, 09 Jul 2010 18:01:55 +0000

This didn’t work for me. I still get “You can specify target table ‘foo’ for update in FROM clause.”

By: Rich

Rich — Tue, 25 May 2010 20:36:29 +0000

Thanks! I’ve been struggling with this too. Thanks to Bruno too!

By: Bruno Ng

Bruno Ng — Tue, 16 Jun 2009 15:31:59 +0000

Here’s the simplified version :
UPDATE my_table t, (SELECT MAX(my_value) + 1 AS selected_value FROM my_table) AS t2 SET t.my_value = t2.selected_value WHERE t.id = 123;

By: Vighnesh

Vighnesh — Fri, 29 May 2009 09:39:48 +0000

Thanks this helped me. I needed same sort of solution.