Question

How i can parse and extract the parameters from an SQL Query using delphi?

example :

from this query

SELECT * FROM MyTable 
WHERE Field1=:Param1 
AND Field2=:Param2 
AND (Field3=:Param3 OR Field4=:Param4)

i want to obtain

Param1
Param2
Param3
Param4

Thanks in advance.

Answer 1

@Salvador, you can use the TParams.ParseSQL function to get the parameters.

see this simple code

program Project241;

{$APPTYPE CONSOLE}

uses
  db, //for use TParams
  Classes,// 
  SysUtils;

procedure GetParamsFromSQL(SQL:string;Const ListParams:TStrings);
var
  ParamList: TParams;
  i: integer;
begin
 ListParams.Clear;//Clear the list
    ParamList := TParams.Create(nil);
    try
      ParamList.ParseSQL(SQL, True); //Force to create the params from the SQL
      for i := 0 to ParamList.Count - 1 do 
        ListParams.Add(ParamList[i].Name);
    finally
    ParamList.Free;
    end;
end;

var
  ParamList : TStrings;
begin
  ParamList:=TStringList.Create;
  try
    GetParamsFromSQL('SELECT * FROM MyTable WHERE Field1=:Param1 AND Field2=:Param2 AND (Field3=:Param3 OR Field4=:Param4)',ParamList);
    Writeln(ParamList.text);
    Readln;
  finally
  ParamList.Free;
  end;
end.

returns :

Param1
Param2
Param3
Param4