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| Some Sql addidtions [message #16562] |
Thu, 26 June 2008 14:56  |
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Recently I made possible to write select in select fields list:
SQL * ::Select(
ID,
NAME,
::Select(NAME, AGE).From(PARENTS).Where(KID_ID == ID),
PHONE
).From(KIDS)
..and conditions
SQL * ::Select(
X == Y,
NUMBER < 100,
).From(TABLE)
SqlNvl has now As() method so it's possible to write:
SQL * ::Select(
(QUANTITY * PRICE).As(FINAL_PRICE)
(NAME | SURNAME).As(FULL_NAME)
).From(PRICES)
It's also possible to write cases:
SQL * ::Select(
ID,
Case(AGE < 5, "Baby")
(Between(AGE, 5, 10), "Kid")
("Young man"),
NAME
.From(PERSONS)
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| Re: Some Sql addidtions [message #16573 is a reply to message #16567] |
Fri, 27 June 2008 23:16  |
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How about to write SQL queries as a simple text?
for example:
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Query *q;
q->SetText ( "SELECT SomeColumns FROM SomeTable WHERE SomeCondition = &SomeParameter GROUP BY SomeGoups HAVING SomeHavingCondition..." )
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?
and after then we can set parameter value;
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q->SetParameter ( "SomeParameter", parameter_value );
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after then we can do:
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QResult *q_result = q->Execute ();
QChoose q_chouse = q_result->Choose ();
while ( q_chouse->Next () ) {...}
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or
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Array q_res = q->Execute ()->Unload ();
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How about thi idea? I thing that this is more simple... and will be possible for sent to an server application only query text!
[Updated on: Fri, 27 June 2008 23:19] Report message to a moderator |
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| Re: Some Sql addidtions [message #16581 is a reply to message #16578] |
Sat, 28 June 2008 23:30 |
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Thank you Mirek! I like this "low level" query!
I tried to compile example package and get folow error:
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C:\uppdev\examples\SQLApp\query.cpp(17) : error C2593: 'operator ==' is ambiguous
c:\uppdev\uppsrc\sql\Sqlexp.h(346): could be 'Upp::SqlBool Upp::operator ==(const Upp::SqlVal &,const Upp::SqlSet &)'
c:\uppdev\uppsrc\sql\Sqlexp.h(308): or 'Upp::SqlBool Upp::operator ==(const Upp::SqlVal &,const Upp::SqlVal &)'
while trying to match the argument list '(Upp::SqlId, Upp::SqlSelect)'
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[Updated on: Sat, 28 June 2008 23:37] Report message to a moderator |
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| Re: Some Sql addidtions [message #16585 is a reply to message #16584] |
Sun, 29 June 2008 21:03 |
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| luzr wrote on Sun, 29 June 2008 19:15 |
| tojocky wrote on Sat, 28 June 2008 17:30 |
Thank you Mirek! I like this "low level" query!
I tried to compile example package and get folow error:
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C:\uppdev\examples\SQLApp\query.cpp(17) : error C2593: 'operator ==' is ambiguous
c:\uppdev\uppsrc\sql\Sqlexp.h(346): could be 'Upp::SqlBool Upp::operator ==(const Upp::SqlVal &,const Upp::SqlSet &)'
c:\uppdev\uppsrc\sql\Sqlexp.h(308): or 'Upp::SqlBool Upp::operator ==(const Upp::SqlVal &,const Upp::SqlVal &)'
while trying to match the argument list '(Upp::SqlId, Upp::SqlSelect)'
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Please, when posting a problem like this, mention the compiler (and platform, but it is obvious here 
Mirek
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Sorry!
platform is Win32 xp, Compiler is MSC8 optimal!
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| Re: Some Sql addidtions [message #16586 is a reply to message #16562] |
Mon, 30 June 2008 09:15 |
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mirek
Messages: 14271
Registered: November 2005
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Ultimate Member |
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| unodgs wrote on Thu, 26 June 2008 08:56 |
Recently I made possible to write select in select fields list:
SQL * ::Select(
ID,
NAME,
::Select(NAME, AGE).From(PARENTS).Where(KID_ID == ID),
PHONE
).From(KIDS)
..and conditions
SQL * ::Select(
X == Y,
NUMBER < 100,
).From(TABLE)
SqlNvl has now As() method so it's possible to write:
SQL * ::Select(
(QUANTITY * PRICE).As(FINAL_PRICE)
(NAME | SURNAME).As(FULL_NAME)
).From(PRICES)
It's also possible to write cases:
SQL * ::Select(
ID,
Case(AGE < 5, "Baby")
(Between(AGE, 5, 10), "Kid")
("Young man"),
NAME
.From(PERSONS)
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Well, you have broken SqlExp in the process
/*
SqlVal::SqlVal(const SqlSelect& x) {
SetHigh('(' + ((SqlStatement) x).GetText() + ')');
}
SqlVal::SqlVal(const SqlBool& x) {
SetHigh(~x);
}
*/
I had to comment these, otherwise I am getting a lot of errors like the one tojocky mentions.
Mirek
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| Re: Some Sql addidtions [message #16589 is a reply to message #16587] |
Mon, 30 June 2008 12:05 |
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| luzr wrote on Mon, 30 June 2008 03:36 |
Well, to avoid this situation in the future, I have moved my "SqlExp documentation examples" package to reference/SqlExp.
This should have two nice purposes:
When you add something new to SqlExp, add example of it to this package. And, by compiling it, there should be a bit of safeguarding against these kinds of bugs...
Mirek
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Good idea. I'll try to fix that (In my app there are so many sqls so I thought I hadn't broken anything..)
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| Re: Some Sql addidtions [message #16593 is a reply to message #16589] |
Mon, 30 June 2008 21:04 |
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Another solution (at least for SqlApp) is to comment
inline SqlBool operator==(const SqlVal& a, const SqlSet& b) { return In(a, b); }
inline SqlBool operator!=(const SqlVal& a, const SqlSet& b) { return NotIn(a, b); }
and using directly In or NotIn instead of SqlVal !=/== SqlSet. IMO it's more readable, but for now I'll leave it as it is. I'll try to find solution without compromise.
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so sometimes is good to use "low-level interface" specially when you don't have e good explanation of "high-level interface" or when you have to do your work in the hard way 
