Handling of Unicode Characters using Delphi 6

Question

I have a polling application developed in Delphi 6. It reads a file, parse the file according to specification, performs validation and uploads into database (SQL S

Answer 1

In non Unicode Delphi version, The basics are that you need to work with WideStrings (Unicode) instead of Strings (Ansi).

Forget about TADOQuery.SQL (TStrings), and work with TADODataSet.CommandText or TADOCommand.CommandText(WideString) or typecast TADOQuery as TADODataSet. e.g:

stlTemp: TWideStringList; // <- Unicode strings - TNT or other Unicode lib
qry: TADOQuery;
stQuery: WideString; // <- Unicode string

TADODataSet(qry).CommandText := stQuery;
RowsAffected := qry.ExecSQL;

You can also use TADOConnection.Execute(stQuery) to execute queries directly.

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Be extra careful with Parametrized queries: ADODB.TParameters.ParseSQL is Ansi. If ParamCheck is true (by default) TADOCommand.SetCommandText->AssignCommandText will cause problems if your Query is Unicode (InitParameters is Ansi).

(note that you can use ADO Command.Parameters directly - using ? chars as placeholder for the parameter instead of Delphi's convention :param_name).

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QuotedStr returns Ansi string. You need a Wide version of this function (TNT)

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Also, As @Arioch 'The mentioned TNT Unicode Controls suite is your best fried for making Delphi Unicode application. It has all the controls and classes you need to successfully manage Unicode tasks in your application.

In short, you need to think Wide :)