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| | Whatever remains will be perhaps a list of supported databases which can be merged with similar lists for FPC... | | Whatever remains will be perhaps a list of supported databases which can be merged with similar lists for FPC... |
| | --[[User:BigChimp|BigChimp]] 06:26, 22 May 2012 (UTC) | | --[[User:BigChimp|BigChimp]] 06:26, 22 May 2012 (UTC) |
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| − | === Suggestions from 2005 - can these be removed? ===
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| − | Is this still relevant or does this need to be removed?
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| − | --[[User:BigChimp|BigChimp]] 11:21, 8 August 2011 (CEST)
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| − |
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| − | Hi,
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| − | I would like to change some code given in the MySQL example for Lazarus. I think there are some fundamental errors here.
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| − | For instance
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| − |
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| − | procedure ShowString (S : string);
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| − | (* display a string in a Memo box *)
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| − | begin
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| − | trymysqlForm1.ResultsMemo.Lines.Add (S)
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| − | end;
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| − |
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| − | should be done in a methode of the form like:
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| − |
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| − | procedure TtrymysqlForm1.ShowString (S : string);
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| − | (* display a string in a Memo box *)
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| − | begin
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| − | ResultsMemo.Lines.Add (S)
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| − | end;
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| − |
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| − | It makes the use of the trymysqlForm1 variable obsolete, which might be the cause of runtime errors.
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| − | Well to cut a long story short, I would like the code to be changed into:
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| − |
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| − | procedure TFormTryMySQL.QueryButtonClick(Sender: TObject);
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| − | var
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| − | tableBuffer: PMYSQL_RES;
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| − | recordBuffer: TMYSQL_ROW;
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| − | fieldList: TStringList;
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| − | I: Integer;
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| − | stMessage: String;
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| − | begin
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| − | // Show how we can get records from a table
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| − | StatusBar1.SimpleText := 'Executing query: ' + CommandEdit.Text;
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| − | ShowString('Executing query: ' + CommandEdit.Text);
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| − | if (mysql_query(mySQLSock, PChar(CommandEdit.Text)) < 0) then begin
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| − | ShowString('Query failed '+ StrPas(mysql_error(mySQLSock)));
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| − | end else begin
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| − | tableBuffer := mysql_store_result(mySQLSock);
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| − | try
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| − | if tableBuffer = nil then begin
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| − | ShowString('Query didnot return any results.');
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| − | end else begin
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| − | fieldList := TStringList.Create;
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| − | try
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| − | ShowString('Number of records returned : ' + IntToStr(mysql_num_rows(tableBuffer)));
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| − | ShowString('Number of fields per record : ' + IntToStr(mysql_num_fields(tableBuffer)));
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| − | // Lets get a list a returned fields.
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| − | for I := 0 to pred(mysql_num_fields(tableBuffer)) do begin
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| − | fieldList.Add(mysql_fetch_field_direct(tableBuffer, I).name);
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| − | end;
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| − | recordBuffer := mysql_fetch_row(tableBuffer);
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| − | while (recordBuffer <> nil) do begin
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| − | stMessage := '';
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| − | for I := 0 to pred(mysql_num_fields(tableBuffer)) do begin
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| − | stMessage := stMessage + fieldList[I] + ': ' + recordBuffer[I] + ', ';
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| − | end;
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| − | Delete(stMessage, Length(stMessage) - 2, 2);
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| − | ShowString(stMessage);
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| − | recordBuffer := mysql_fetch_row(tableBuffer);
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| − | end;
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| − | finally
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| − | fieldList.Free;
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| − | end;
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| − | end;
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| − | finally
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| − | // Free the results, thus saving resources.
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| − | mysql_free_result(tableBuffer);
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| − | end;
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| − | end;
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| − | end;
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| − |
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| − | There are some more changes, in fact I expanded it with a second form to show data in a ListView. So if there is any interest in that I'm willing to [http://prdownloads.sourceforge.net/lazarus-ccr/trymysql20050404.tar.gz?download contribute] it to the documentation project.
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| − |
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| − | [[user:Matthijs|Matthijs]]
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| − |
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| − | This page has been converted from the epikwiki [http://lazarus-ccr.sourceforge.net/index.php?wiki=LazarusDatabase version].
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| − | ------
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