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Some queries return incorrect datatypes with SqLite [message #55728]

Thu, 03 December 2020 18:56

Alboni
Messages: 216
Registered: January 2012
Location: Kajaani, Finland

Experienced Member

Hello, I see some issue with SqLite3 lately that didn't exist before.

They have to do with the datatype of the results of a query.

issue 1 : SqlMax(some time column) returns WSTRING_V result instead of TIME_V
issue 2 : Selecting a BOOL column also returns WSTRING_V result instead of BOOL_V

again, it only applies to SqLite, on MySql it works correctly

I enclosed an example

Attachment: SqLiteIssues.zip
(Size: 1.33KB, Downloaded 281 times)

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Re: Some queries return incorrect datatypes with SqLite [message #55767 is a reply to message #55728]

Fri, 11 December 2020 14:55

mirek
Messages: 14291
Registered: November 2005

Ultimate Member

Alboni wrote on Thu, 03 December 2020 18:56

Hello, I see some issue with SqLite3 lately that didn't exist before.

They have to do with the datatype of the results of a query.

issue 1 : SqlMax(some time column) returns WSTRING_V result instead of TIME_V
issue 2 : Selecting a BOOL column also returns WSTRING_V result instead of BOOL_V

again, it only applies to SqLite, on MySql it works correctly

I enclosed an example

BOOL behaviour is as expected (BOOL in .sch is always emulated by text column to be consistent across all DBs).

With SqlMax it seems we are simply out of luck:

https://www.sqlite.org/c3ref/column_decltype.html

Impossible to do better there I am afraid Sad

Mirek

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Re: Some queries return incorrect datatypes with SqLite [message #55768 is a reply to message #55767]

Fri, 11 December 2020 15:17

Alboni
Messages: 216
Registered: January 2012
Location: Kajaani, Finland

Experienced Member

But regardless of implementation, with Mysql an assignment to a bool variable goes right.

I have no issue discontinuing BOOL_ and using INT_ instead if it is too tricky or not worth it to fix.

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Re: Some queries return incorrect datatypes with SqLite [message #55770 is a reply to message #55768]

Fri, 11 December 2020 15:42

mirek
Messages: 14291
Registered: November 2005

Ultimate Member

Well, that is rather nasty inconsistence with MySql.... Sorry, long time ago MySql was contributed package and I missed this one. Cannot fix that now without breaking existing code Sad

That said, maybe we could introduce a new schema type, e.g. "LOGICAL" that maps to bool and uses database 'bool' where possible and smallest number where not possible?

Mirek

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Re: Some queries return incorrect datatypes with SqLite [message #55773 is a reply to message #55728]

Fri, 11 December 2020 16:43

Alboni
Messages: 216
Registered: January 2012
Location: Kajaani, Finland

Experienced Member

ok. Thanks.
I'll use int for now.

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