Question

i’m using vs2008 and SQLLite.Net,
when i using these code:

String sel = "select * from admins where [name]='admin88' and [password]='123456'";
System.Data.SQLite.SQLiteConnection conn = new System.Data.SQLite.SQLiteConnection();
conn.ConnectionString = Config.connStr;
conn.Open();

System.Data.SQLite.SQLiteCommand cmd = new System.Data.SQLite.SQLiteCommand();


cmd.CommandText = sel;
cmd.CommandType = CommandType.Text;

cmd.Connection = conn;

DataSet set = new DataSet();
System.Data.SQLite.SQLiteDataAdapter adp = new System.Data.SQLite.SQLiteDataAdapter() ;
adp.SelectCommand = cmd;
adp.Fill(set);
adp.Dispose();

Response.Write(set.Tables.count);

it works.
but when i using parameters ,return null:

String sel = "select * from admins where [name]=@name and [password]=@pass";
cmd.Parameters.Clear();
cmd.Parameters.Add(new System.Data.SQLite.SQLiteParameter("@name", "admin88"));
cmd.Parameters.Add(new System.Data.SQLite.SQLiteParameter("@pass", "123456"));

Answer 1

Ref: SQL As Understood By SQLite

:AAAA A colon followed by an identifier name holds a spot for a named
parameter with the name :AAAA. Named parameters are also numbered.

Your query should be as:

String sel = "select * from admins where [name]= :name and [password]= :pass";

Add parameters without @ symbol. Check the following code snippet.

SQLiteParameter[] myParams = new SQLiteParameter[]  
    { 
      new SQLiteParameter("DeptNo", 10), 
      new SQLiteParameter("DName", "COUNTING") 
    }; 
  SQLiteConnection sqConnection1 = new SQLiteConnection("DataSource=mydatabase.db"); 
  CreateCommand(sqConnection1,"UPDATE Dept SET DName = :DName WHERE DeptNo = :DeptNo",myParams); 

Reference this.