Is there any way to put text into SQL using Delphi? [duplicate] - sql

Question

Using Delphi 2010
Can anyone tell me what I am doing wrong here with my code. The comments show the errors that I receive with the particular methods that I tried to pass parameters to my ADOQuery
procedure CreateAdminLogin(const APasswd: string);
var
qry: TADOQuery;
//P1, P2: TParameter;
begin
qry := TADOQuery.Create(nil);
try
qry.Connection := frmDataModule.conMain;
qry.SQL.Text := 'INSERT INTO Users (User_Id, Password) VALUES (:u, :p)';
//Syntax error in INTO statement
qry.Parameters.ParamByName('u').Value:= 'Admin';
qry.Parameters.ParamByName('p').Value:= GetMd5(APasswd);
//invalid variant operation
{qry.Parameters.ParamByName('u').Value.AsString:= 'Admin';
qry.Parameters.ParamByName('p').Value.AsString:= GetMd5(APasswd);}
//invalid variant operation
{P1:= qry.Parameters.ParamByName('u');
P1.Value.asString:= 'Admin';
P2:= qry.Parameters.ParamByName('p');
P2.Value.asString:= GetMd5(APasswd);}
qry.Prepared := True;
qry.ExecSQL;
finally
qry.Free;
end;
end;
NOTE: GetMD5 is declared as follows
function GetMd5(const Value: String): string;
var
hash: MessageDigest_5.IMD5;
fingerprint: string;
begin
hash := MessageDigest_5.GetMd5();
hash.Update(Value);
fingerprint := hash.AsString();
Result := fingerprint;
end;
Thankx

Answer 1

This works fine for me, using the DBDemos.MDB file that shipped with Delphi (C:\Users\Public\Documents\RAD Studio\9.0\Samples\Data\dbdemos.mdb by the default installation)
ADOQuery1.SQL.Clear;
ADOQuery1.SQL.Add('INSERT INTO Country (Name, Capital, Continent, Area, Population)');
ADOQuery1.SQL.Add('VALUES (:Name, :Capital, :Continent, :Area, :Population)');
ADOQuery1.Parameters.ParamByName('Name').Value := 'SomePlace';
ADOQuery1.Parameters.ParamByName('Capital').Value := 'Pitsville';
ADOQuery1.Parameters.ParamByName('Continent').Value := 'Floating';
ADOQuery1.Parameters.ParamByName('Area').Value := 1234;
ADOQuery1.Parameters.ParamByName('Population').Value := 56;
ADOQuery1.ExecSQL;
ADOQuery1.Close;
// Open it to read the data back
ADOQuery1.SQL.Text := 'SELECT * FROM Country WHERE Name = :Name';
ADOQuery1.Parameters.ParamByName('Name').Value := 'SomePlace';
ADOQuery1.Open;
ShowMessage(ADOQuery1.FieldByName('Name').AsString);

Answer 2

For using like extra thing to know:
Datasource SQL like this
select * from Table where Phone like :param
DataModule.findQuery.Parameters.ParamByName('param').Value:= '%%'+yourEdit.Text + '%%';

Answer 3

You should create parameters first:
procedure CreateAdminLogin(const APasswd: string);
var
qry: TADOQuery;
begin
qry := TADOQuery.Create(nil);
try
// this part is missed in your code
with qry.Parameters.AddParameter do
begin
Name := 'u';
DataType := ftString;
end;
with qry.Parameters.AddParameter do
begin
Name := 'p';
DataType := ftString;
end;
qry.Connection := frmDataModule.conMain;
qry.SQL.Text := 'INSERT INTO Users (User_Id, Password) VALUES (:u, :p)';
// Now it will be ok!
qry.Parameters.ParamByName('u').Value:= 'Admin';
qry.Parameters.ParamByName('p').Value:= GetMd5(APasswd);
qry.Prepared := True;
qry.ExecSQL;
finally
qry.Free;
end;
end;