I just spent the last hour trying to debug the smallest SQL problem! I have a datatable of Contracts and I was building a feature in our client software where we could end all contracts of a certain type (SLA) at the same time (trust me, there is a business reason behind this). To do this, I was executing the following MySQL Cross-Table UPDATE statement:
UPDATE contract c INNER JOIN contract_type t ON ( t.reference_key = 'SLA' AND c.contract_type_id = t.id ) SET c.date_updated = <cfqueryparam value="#Now()#" cfsqltype="cf_sql_timestamp" /> AND c.date_ended = <cfqueryparam value="#Now()#" cfsqltype="cf_sql_timestamp" /> WHERE c.date_ended IS NULL
I'm trying to set the date_ended field to Now() where ever it is currently NULL and of the correct contract type (SLA). However, when I ran this query, MySQL kept throwing this error:
Data truncation: Truncated incorrect DOUBLE value: '2009-02-18 13:43:35'
The error certainly wants you to believe that this is a data problem. Specifically, the error wants you to believe that the date/time value you are using in the query is somehow being converted to a double and that the converted value is too big for a double. So naturally, that's what I was trying to debug. But, after a solid hour, no joke, I came to realize that this error has nothing to do with data at all and is, in fact, a syntax error!
Look at my SET statement:
SET c.date_updated = <cfqueryparam value="#Now()#" cfsqltype="cf_sql_timestamp" /> AND c.date_ended = <cfqueryparam value="#Now()#" cfsqltype="cf_sql_timestamp" />
See the problem now? I have it written out like a WHERE statement; a proper SET statement uses commas, not ANDs. Rewritten properly, the query is:
UPDATE contract c INNER JOIN contract_type t ON ( t.reference_key = 'SLA' AND c.contract_type_id = t.id ) SET c.date_updated = <cfqueryparam value="#Now()#" cfsqltype="cf_sql_timestamp" />, c.date_ended = <cfqueryparam value="#Now()#" cfsqltype="cf_sql_timestamp" /> WHERE c.date_ended IS NULL
So yeah, that's an hour of my life I won't get back. That's a really poor error that MySQL is throwing. Not that I'm blaming MySQL - I was the one who wrote the crappy statement - but, it did sort of lead me on a wild goose chase. Next time, thought, I'll be prepared!
Good thing that you have your own company. If you worked for someone they might have ripped you for "wasting" an hour.
Those bugs are so much fun.
Hey, I was still doing client work :)
Just curious. Why did you write out:
c.date_ended = <cfqueryparam value="#Now()#" cfsqltype="cf_sql_timestamp" />
When MySQL has a built in "now()" function. Would it be cleaner (and a mirco-fraction faster) if you did this:
c.date_ended = now()
I imagine you have your reasons.
To keep the SQL cross DB compliant
DB server isn't in same timezone as Webserver
I just use it out of habit. I like to keep the SQL as consistent as possible and so I use CFQueryParam for ally my dynamic value. Plus, sometimes I have dates that have to be null based on other values and CFQueryParam makes that wicked easy:
<cfqueryparam value="#FORM.date_started#" type="cf_sql_timestamp" null="#(NOT IsDate( FORM.date_started ))#" />
With this, I can put my null-ify logic right into the CFQueryParam tag and keep my SQL free of CFIF statements regarding NULL inserts.
WOW. I just did the same thing! I actually spent a couple hours trying to figure this out :(
Yeah, the error message is SOOOO misleading!
Whahaha. You just saved me an hour ;)
No problem my man :) It's a horribly unhelpful error message, so glad to help.
same mistake here.
the error message REALLY HELPED(in making debugging more complex I mean:P)
Thanks for that one Ben :)
Wow, you just saved me an hour. Thanks.
Thanks man, saved me an hour for sure...will remember this one for a long time.
Thanks very much!Actually you saved me an hour.and thanks you one hour.
Glad to help out guys.
Just saved me a morning of frustration too!
MySQL raised same crappy error on the following syntax:
select IFNULL(id,0)+1 into nextval from nextids where UPPER(tablename)=UPPER('''' + tbname + '''')
The correct syntax should be:
select IFNULL(id,0)+1 into nextval from nextids where UPPER(tablename)=UPPER(CONCAT('''',tbname,''''));
Thank you,Ben. It is your post that enlightened me to stop searching for errors in places where there aren't chances to find one :))
Going from MS SQL to MySQL, it took me a while to get in the mindset of CONCAT(). In MS SQL, using the "+" is so easy.
You wasted an hour of your life but saved me one - thanks for posting this!
Yes, Ben, couldn't they just have used that tiny "+" sign? :))
Oh, another thing!
After using the concat, i kept receiving this error: "No data fetched and-some-other-thing-bla-bla" Said to myself: "Bugger! What could be wrong this time?"
Well, since I am a Delphi developer, at my origins, i always add the quotes when comparing a constant-value string to a variable string/a string-type parameter.
Well (again), it seems that MySQL doesn't need the quotes, it has it's own. Very ashamed of not knowing this, stop "boo"-ing me.
So, finally, the winning syntax was:
select IFNULL(id,0)+1 into nextval from nextids where UPPER(tablename)=UPPER(tbname)
It was right there, in front of me, all the time :)
Nice night to you, Ben, and thanks again.
Sometimes, error just seem to do more harm than good :) They almost act as misdirection.
Saved me the hour! Thanks!
Similar issue: appear to have a problem with a double, but that is not the cause....
create table test (col1 varchar(10), col2 varchar(10), col3 double);
insert into test values ("a","b",0);
update test set col3=1.2 where col1+col2="a"+"b";
Query OK, 1 row affected, 2 warnings (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 0
| Level | Code | Message |
| Warning | 1292 | Truncated incorrect DOUBLE value: 'a' |
| Warning | 1292 | Truncated incorrect DOUBLE value: 'b' |
update test set col3=1.2 where concat(col1,col2)="a"+"b";
Query OK, 0 rows affected, 2 warnings (0.00 sec)
Rows matched: 1 Changed: 0 Warnings: 0
To work without warnings,
update test set col3=1.2 where col1+col2=concat("a","b");
update test set col3=1.2 where concat(col1,col2)=concat("a","b");
Not that this is related to the problem at all, but don't you need single quotes when dealing with SQL string values?
No, double quotes work as well. He just has to pay attention to the letter case.
Really? I had no idea. Is this true for all SQL? Or just some databases?
Weeeeelll ... it did apply to MySQL and SQL Server and Firebird.
Can't be sure about Interbase, though, it's been a long time.
Very cool; I'll have to give this a try.
Keep me posted. Who knows? Some things might have changed.
Same error in 5.0.67 :(
oh well thanks for saving my debugging time.
Thanks to Google and your blog I now know why I have been getting this error for the past 3 months. Now I don't have to update fields one by one like a sucker.
Awesome my man. Glad this was able to help you sort out the problems.
Ben, you just saved me a lot of time. Thanks!
Nice work, Ben. I can really count on you. Seriously.
@Ari, @Hrish, @Mike,
Always happy to help. Glad this post helped you narrow down your problem.
Thanks a loads man!!
hw silly on my part
Commas, not ANDs in MySQL UPDATE statements. Just what I needed - thanks for posting those comments - you rock.
Awesome, saved my time.
Small but very typical syntax error.
U saved my hour.
Well FWIW you saved ME an hour tonight.
Thaks for your hour man!!!!
I have created a procedure in mysql to create a dynamic table ,although the procedure is prepared successfully but by a call myp(args);
Its giving an error:Truncated incorrect Double value:'CREATE TABLE'
The code is written below
please help !
Create Procedure myp
(IN t_name VARCHAR(25) )
declare sqlString VARCHAR(150) ;
declare tableName VARCHAR(30);
set tableName :=t_name;
set sqlString :='CREATE TABLE '|| tableName || '(order_id VARCHAR NOT NULL, item_id VARCHAR NOT NULL)';
Two years later and still the same crappy error message.
Thanks for this, it saved me a headache.
LOL i've got the same problem. thanks dude
Thanks. saved one hour :)
you're awesome man!haha this error gave me trouble also..thanks a lot! \m/
Thanks! I owe you one.
Your hour saved up lots of other developer's hours! Thanks :)
I had the same problem. And thanks to you, you saved me from wasting an hour.
I wasted an hour and then searched :(