Unicode parametric query
lazarus / 16-Databases

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djdjdjole · 2016-08-25 18:25

I don't know whether this question is for Lazarus or UniDAC forum. I
have some Serbian Latin strings in my SQL Server. My query is simple
one and is quoted in UniQuery SQL property at design time as: select *
from mytable where name='Šeki'. I correctly receive the only record
which satisfied condition. However when I change the query to: select
* from mytable where name=:par0 and in code:
query.parambyname(par0).asstring:= 'Šeki', I receive no record. Field
"name" is "nvarchar" in database, collation Croatian, client OS-
Windows10 (64- bit), database machine is Windows Server 2012 (64- bit)
and Lazarus version is 1.6.

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zeljko · 2016-08-25 18:32

You written everything except fpc version and database type, anyway,
I'm using postgresql + ZEOS + Lazarus trunk (QtLCL) + fpc 3.0.0 (2.6.4
also worked fine) and never had such problems (linux, mac, windows).
eg
RQRY = zeos readonly query
RQRY.SQL.Add('SELECT * FROM names WHERE name=:P1');
RQRY.Params[0].AsString := 'Željko';
RQRY.Active := True;
.... works fine on any mentioned OS ...returns record

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djdjdjole · 2016-08-25 19:28

FPC is 3.0 and database is SQL Server 2012 Express. No matter I will
try my luck with Zeos components, but still sounds strange to me that
UniDAC (I understood that you pointed the finger to it) behaves
differently in two mentioned situations.

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paweld · 2016-08-25 19:37

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i
Query.SQL.Text:='select * from mytable where name=:par0';//if "name"
field type is varchar Query.Params[0].AsString:=UTF8ToCP1250('Šeki');
//add LConvEncoding unit to uses section//or if "name" field type is
nvarcharQuery.Params[0].AsString:=UTF8ToUTF16('Šeki'); //add LazUTF8
unit to uses section

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djdjdjole · 2016-08-25 19:55

I've already tried that with no success. It sounds reasonable, because
SQL Server's encoding format is UTF-16 (as much as I know) and
Lazarus's one is UTF-8, but the problem is obviously somewhere else.

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djdjdjole · 2016-08-25 19:59

My excuse to paweld - I didn't noticed line number 3, which I didn't
try . It should be first thing tomorrow.

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djdjdjole · 2016-08-26 07:35

The field is of "nvarchar" type in database and attempt with
Utf8ToUtf16 doesn't work- returns no record. When building SQL query
in source :
SQL.Add('select * from myTable where name=');
SQL.Add(QuotedStr('Šeki'));
it does work- returns one record.

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zeljko · 2016-08-26 10:57

Have you tried to add {$codepage utf8} into that unit ? Maybe 'Šeki'
is interpreted as cp1250 ...

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djdjdjole · 2016-08-26 17:26

Logical assumption, still it gives no solution. So I decided to build
query in code- without parameters.

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paweld · 2016-08-26 18:16

try to use macros:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i
Query.SQL.Text:='select * from mytable where
name=&mac0';Query.Macros[0].AsString:='Šeki';

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djdjdjole · 2016-08-27 10:44

Simply no way- tried and returned no record. You guys are so kind and
persistent - I have no words to express my gratitude. At the moment I
found the way to override the problem (I already wrote about), but it
still remains mystery to me.