C# sqliet 读写 *.db 数据库

public static string DbPath = string.Format(@"Data Source={0}", 
System.Windows.Forms.Application.StartupPath + @"\1.db"); 
public static DataTable GetDataTable(string sSQL) 
        { 
            DataTable dt = null; 
            try 
            { 
                SQLiteConnection conn = new SQLiteConnection(DbPath); 
                SQLiteCommand cmd = new SQLiteCommand(); 
                cmd.CommandText = sSQL; 
                cmd.Connection = conn; 
                SQLiteDataAdapter dao = new SQLiteDataAdapter(cmd); 
                dt = new DataTable(); 
                dao.Fill(dt); 
                return dt; 
            } 
            catch 
            { 
                 return null; 
            } 
            return null; 
        } 
//上面是取datatable的，稍修改一下就可以变成执行语句的 
public static int ExecuteSQL(string sSQL) 
        { 
            DataTable dt = null; 
           using(SQLiteConnection conn = new SQLiteConnection(DbPath)) 
            { 
                SQLiteCommand cmd = new SQLiteCommand(); 
                conn.Open(); 
                cmd.CommandText = sSQL; 
                cmd.Connection = conn; 
                return cmd.ExecuteNonQuery(); 
            } 
            catch 
            {                 
            } 
            return 0; 
        }  

 //调用的时候比如取所有数据 
DataTable dt=GetDataTable("select * from tablename"); 
//修改某人数据 
string str="update tablename set sex='{0}',age={1} where uname='{2}'"; 
str=string.Format(sql,'男',20,'张三'); 
if(ExecuteSQL(str)>0) MessageBox.Show("修改成功"); 
else MessageBox.Show("修改失败");