Are unamed Params supported in TSQLQuery ?
lazarus / 16-Databases

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eara · 2014-04-16 13:55

I know for named params, but what about unamed params?
e.g.

select x,y,z from table1 where x=? and y=? and z=?;

is this supported (delphi  had it, i think)

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Windsurfer · 2014-04-16 19:20

See http://www.freepascal.org/docs-
html/ref/refse69.html#x128-13800012.2

and http://wiki.lazarus.freepascal.org/Parameters

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eara · 2014-04-16 20:51

Quote from: Windsurfer on April 16, 2014, 09:20:31 pmSee
http://www.freepascal.org/docs-html/ref/refse69.html#x128-13800012.2

and http://wiki.lazarus.freepascal.org/Parameters
What has this to do with my question ???

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valdir.marcos · 2014-04-17 02:14

Are you talking about Firebird Execute Block?
http://www.firebirdsql.org/refdocs/langrefupd25-execblock.html

-------------------------------------------
The next example calculates the geometric mean of two numbers and
returns it to the user:
Code: [Select]execute block (x double precision = ?, y double
precision = ?)
returns (gmean double precision)
as
begin
  gmean = sqrt(x*y);
  suspend;
end


Because this block has input parameters, it has to be prepared first.
Then the parameters can be set and the block executed. It depends on
the client software how this must be done and even if it is possible
at all – see the notes below.

Our last example takes two integer values, smallest and largest. For
all the numbers in the range smallest .. largest, the block outputs
the number itself, its square, its cube and its fourth power.
Code: [Select]execute block (smallest int = ?, largest int = ?)
returns (number int, square bigint, cube bigint, fourth bigint)
as
begin
  number = smallest;
  while (number <= largest) do
  begin
    square = number * number;
    cube   = number * square;
    fourth = number * cube;
    suspend;
    number = number + 1;
  end
end
Again, it depends on the client software if and how you can set the
parameter values.
-------------------------------------------

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LacaK · 2014-04-17 04:40

Quote from: eara on April 16, 2014, 03:55:14 pmI know for named
params, but what about unamed params?
e.g.

select x,y,z from table1 where x=? and y=? and z=?;

is this supported (delphi  had it, i think)
Theoretically it can work, but then you must manually add parameters
to TSQLQuery.Params collection.
And it depends on SQLConnection type ... it can work for
TIBConnection, but not for MySQLConnection for example.

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taazz · 2014-04-17 04:54

as far as I can see the TParams.ParseSQL method supports named and
unnamed parameters. Try for your self use a statement like select *
from MyTable where MyField = ?and see how that goes.

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eara · 2014-04-17 06:31

thank you both for your anwsers again, i made my tries on MySQL with
unamed (didn't try with Add params), and moved to named params again.

It was in a attempt to send to MySQL a lot of tag words at once but
with a secure way (against sql injections,where FCL hides the
mysql_real_escape_string() into a private EscapeString()). Finally i
made it but as i see not at once (due to many parameters, this seems
that it needs a stored procedure for that).
one query is  something like that

Code: [Select]qry_.SQL.Text:=Format('insert ignore into tags (tag)
select temp.tag from (%s) temp',[s]);
for i:=0 to value_list.count-1 do
  qry_.ParamByName(IntToStr(i)).AsString:=value_list.strings[i];
which seems to work, in my tests i managed to send 3000 tags with one
query (takes some sec, due to roundtrips for 3000 params), which seems
to cover my needs for the time.

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eara · 2014-04-19 22:53

QuoteTheoretically it can work, but then you must manually add
parameters to TSQLQuery.Params collection.
And it depends on SQLConnection type ... it can work for
TIBConnection, but not for MySQLConnection for example.Theoretically
means no for me.... i made my tests with MySQL, didn't work... never
mind, go fwd...
thank you all again...