[SOLVED] Lazarus + Firebird how to delete from table!?
lazarus / 16-Databases

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nicke85 · 2010-09-21 16:07

I'm new with firebird database and don't know how to delete  from
table..
I want one or two Edit1.Text components on form to use like criterium
for delete from table..
What I need to do..!?
If write
    Code: [Select]SQLQuery1.SQL.Text:='delete from (table) where
xxx=:' + Edit1.Text;
it doesnt work..
does somebody can write me steps and components without
SQLQuery1.DeleteSQL component..

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mirce.vladimirov · 2010-09-21 20:44

I dont know about the FirebirdSQL, I have never used it, but I think
that you need to enclose the edit1.text in single qutoes, because it
is a string. Strings must be quoted with single quotes. And number
two, I believe that the equation sign is typed incorectly, it should
not be
xxx:='some text'
like in pascal/delphi/lazarus, the SQL correct gramar is just '='
xxx='some text'

Code: [Select]
SQLQuery1.SQL.Text:='delete from table where xxx=' + #39 + Edit1.Text
+ #39;

The character #39 is a single quote. This line of code would be same
like if you typed to the SQL prompt the following:

Code: [Select]delete from table where xxx='this is the text contained
in the edit1';

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Lacak2 · 2010-09-22 04:12

Yes, and you can also use syntax with parameter:

Code: [Select]SQLQuery1.SQL.Text:='delete from table where xxx=:xxx';
SQLQuery1.Params.ParamByName('xxx').AsString:='some text';
SQLQuery1.ExecSQL;

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nicke85 · 2010-09-23 17:26

Thanks for reply mirce.vladimirov and Lacak2...
For Firebird conection I need IBConnection1,SQLTransaction and
SQLQuery..i know how to insert,update make functions but don't know
how to delete..
What is with SQLTransaction when i need to delete from table!?
I got every time that data from table is errased but there is no
change into table for really...

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Lacak2 · 2010-09-24 04:05

May be, that you must also Commit changes using:
Code: [Select]SQLTransaction1.Commit; or
SQLTransaction1.CommitRetaining

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jagorath · 2010-09-24 04:54

As an aside, you can use QuotedStr from SysUtils as an alternative to
#39 or a quote character, e.g.

Code: [Select]SQLQuery1.SQL.Text:= 'delete from table where xxx=' +
QuotedStr(Edit1.Text);

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nicke85 · 2010-09-26 12:41

Lacak2 open SQLTransaction1 solve my problem for Insert and Update but
real problem was in QuotedStr like jarogath wrote..
And Yes!!!!It solved my problem thanks you a lot for help jarogath