Database ADO.net

Illustrates simple stored procedures with unnamed parameters in the query

Posted on by coder 


   

using System;
using System.Data;
using System.Data.OleDb;

public class Prepare {    
 public static void Main () { 
   String connect = "Provider=Microsoft.JET.OLEDB.4.0;data source=.Employee.mdb";
   OleDbConnection con = new OleDbConnection(connect);
   con.Open();  
   Console.WriteLine("Made the connection to the database");

   OleDbCommand cmd = con.CreateCommand();
   cmd.CommandText ="SELECT First_name FROM Employee WHERE ID = ?";
   OleDbParameter param = new OleDbParameter();
   cmd.Parameters.Add(param);
   param.Value = "01";
   OleDbDataReader reader = cmd.ExecuteReader();
   Console.WriteLine("Using a stored procedure");
   while(reader.Read()) 
     Console.WriteLine("{0}", reader.GetString(0));
   reader.Close();

   param.Value = "01";
   reader = cmd.ExecuteReader();
   Console.WriteLine("Using a stored procedure");
   while(reader.Read()) 
     Console.WriteLine("{0}", reader.GetString(0));
   reader.Close();


   con.Close();
 }
}

Call the SQL Server AddProduct() stored procedure with SqlCommand

Posted on by coder 
   
 

using System;
using System.Data;
using System.Data.SqlClient;

class ExecuteAddProduct {
    public static void Main() {
        SqlConnection mySqlConnection = new SqlConnection("server=localhost;database=Northwind;uid=sa;pwd=sa");
        mySqlConnection.Open();
        SqlCommand mySqlCommand = mySqlConnection.CreateCommand();
        mySqlCommand.CommandText =
          "EXECUTE AddProduct @MyProductID OUTPUT, @MyProductName, " +
          "@MySupplierID, @MyCategoryID, @MyQuantityPerUnit, " +
          "@MyUnitPrice, @MyUnitsInStock, @MyUnitsOnOrder, " +
          "@MyReorderLevel, @MyDiscontinued";

        mySqlCommand.Parameters.Add("@MyProductID", SqlDbType.Int);
        mySqlCommand.Parameters["@MyProductID"].Direction = ParameterDirection.Output;
        mySqlCommand.Parameters.Add("@MyProductName", SqlDbType.NVarChar, 40).Value = "Widget";
        mySqlCommand.Parameters.Add("@MySupplierID", SqlDbType.Int).Value = 1;
        mySqlCommand.Parameters.Add("@MyCategoryID", SqlDbType.Int).Value = 1;
        mySqlCommand.Parameters.Add("@MyQuantityPerUnit", SqlDbType.NVarChar, 20).Value = "1 per box";
        mySqlCommand.Parameters.Add("@MyUnitPrice", SqlDbType.Money).Value = 5.99;
        mySqlCommand.Parameters.Add("@MyUnitsInStock", SqlDbType.SmallInt).Value = 10;
        mySqlCommand.Parameters.Add("@MyUnitsOnOrder", SqlDbType.SmallInt).Value = 5;
        mySqlCommand.Parameters.Add("@MyReorderLevel", SqlDbType.SmallInt).Value = 5;
        mySqlCommand.Parameters.Add("@MyDiscontinued", SqlDbType.Bit).Value = 1;
        mySqlCommand.ExecuteNonQuery();
        Console.WriteLine("New ProductID = " + mySqlCommand.Parameters["@MyProductID"].Value);
        mySqlConnection.Close();
    }
}

Add parameters to SqlCommand to call stored procedure

Posted on by coder 
   
 

using System;
using System.Data;
using System.Data.SqlClient;

class ExecuteAddProduct3 {
    public static void Main() {
        SqlConnection mySqlConnection = new SqlConnection("server=localhost;database=Northwind;uid=sa;pwd=sa");
        mySqlConnection.Open();
        SqlCommand mySqlCommand = mySqlConnection.CreateCommand();
        mySqlCommand.CommandText =
          "EXECUTE @MyProductID = AddProduct @MyProductName, " +
          "@MySupplierID, @MyCategoryID, @MyQuantityPerUnit, " +
          "@MyUnitPrice, @MyUnitsInStock, @MyUnitsOnOrder, " +
          "@MyReorderLevel, @MyDiscontinued";

        mySqlCommand.Parameters.Add("@MyProductID", SqlDbType.Int);
        mySqlCommand.Parameters["@MyProductID"].Direction = ParameterDirection.Output;
        mySqlCommand.Parameters.Add("@MyProductName", SqlDbType.NVarChar, 40).Value = "Widget";
        mySqlCommand.Parameters.Add("@MySupplierID", SqlDbType.Int).Value = 1;
        mySqlCommand.Parameters.Add("@MyCategoryID", SqlDbType.Int).Value = 1;
        mySqlCommand.Parameters.Add("@MyQuantityPerUnit", SqlDbType.NVarChar, 20).Value = "1 per box";
        mySqlCommand.Parameters.Add("@MyUnitPrice", SqlDbType.Money).Value = 5.99;
        mySqlCommand.Parameters.Add("@MyUnitsInStock", SqlDbType.SmallInt).Value = 10;
        mySqlCommand.Parameters.Add("@MyUnitsOnOrder", SqlDbType.SmallInt).Value = 5;
        mySqlCommand.Parameters.Add("@MyReorderLevel", SqlDbType.SmallInt).Value = 5;
        mySqlCommand.Parameters.Add("@MyDiscontinued", SqlDbType.Bit).Value = 1;

        SqlDataReader mySqlDataReader = mySqlCommand.ExecuteReader();
        while (mySqlDataReader.Read()) {
            Console.WriteLine("mySqlDataReader[" ProductName"] = " + mySqlDataReader["ProductName"]);
            Console.WriteLine("mySqlDataReader[" UnitPrice"] = " + mySqlDataReader["UnitPrice"]);
        }
        mySqlDataReader.Close();
        Console.WriteLine("New ProductID = " + mySqlCommand.Parameters["@MyProductID"].Value);

        mySqlConnection.Close();
    }
}

SqlException detail info: line number, procedure, server

Posted on by coder 
   


using System;
using System.Data;
using System.Data.SqlClient;

   class SqlExceptionDemo {
      static void Main(){
         string connString = "server=(local)SQLEXPRESS;database=MyDatabase;Integrated Security=SSPI";

         SqlConnection conn = new SqlConnection(connString);
         SqlCommand cmd = conn.CreateCommand();

         cmd.CommandType = CommandType.StoredProcedure;
         cmd.CommandText = "wrong command";

         try {
            conn.Open();
            cmd.ExecuteNonQuery();
         }  
         catch (System.Data.SqlClient.SqlException ex)
         {
            string str;
            str = "Source:"+ ex.Source;        
            str += "
"+ "Number:"+ ex.Number.ToString();
            str += "
"+ "Message:"+ ex.Message;
            str += "
"+ "Class:"+ ex.Class.ToString ();
            str += "
"+ "Procedure:"+ ex.Procedure.ToString();
            str += "
"+ "Line Number:"+ex.LineNumber.ToString();
            str += "
"+ "Server:"+ ex.Server.ToString();
        
            Console.WriteLine (str, "Database Exception");
         }
         catch (System.Exception ex)
         {
            string str;
            str = "Source:"+ ex.Source;
            str += "
"+ "Error Message:"+ ex.Message;
            Console.WriteLine (str, "General Exception");
         }
         finally
         {
            if (conn.State == ConnectionState.Open)
            {
               Console.WriteLine ("Finally block closing the connection", "Finally");
               conn.Close();
            }        
         } 
      }
   }

Deal with multiple Sql error in SqlException

Posted on by coder

using System;
using System.Data;
using System.Data.SqlClient;

class SqlExceptionDemo {
static void Main(){
string connString = “server=(local)SQLEXPRESS;database=MyDatabase;Integrated Security=SSPI”;

SqlConnection conn = new SqlConnection(connString);
SqlCommand cmd = conn.CreateCommand();

cmd.CommandType = CommandType.StoredProcedure;
cmd.CommandText = “wrong”;

try
{
conn.Open();
cmd.ExecuteNonQuery();
}
catch (System.Data.SqlClient.SqlException ex)
{
string str =””;
for (int i = 0; i < ex.Errors.Count; i++) { str += " " + "Index #" + i + " " + "Exception : " + ex.Errors[i].ToString() + " " + "Number:" + ex.Errors[i].Number.ToString() + " " ; } Console.WriteLine(str); } catch (System.Exception ex) { string str; str = "Source:"+ ex.Source; str += " "+ "Error Message:"+ ex.Message; Console.WriteLine (str); } finally { if (conn.State == ConnectionState.Open) { Console.WriteLine ("Finally block closing the connection", "Finally"); conn.Close(); } } } } [/csharp]

Catch Sql command exceptions

Posted on by coder 
   



using System;
using System.Data;
using System.Data.SqlClient;

   class SqlExceptionDemo {
      static void Main(){
         string connString = "server=(local)SQLEXPRESS;database=MyDatabase;Integrated Security=SSPI";

         SqlConnection conn = new SqlConnection(connString);

         SqlCommand cmd = conn.CreateCommand();
      
         cmd.CommandType = CommandType.StoredProcedure; 
         cmd.CommandText = "something wrong here";

         try {
            conn.Open();
 
            SqlDataReader dr = cmd.ExecuteReader();

            string str = dr.GetValue(20).ToString();

            dr.Close();
         }
         catch (System.InvalidOperationException ex)
         {
            string str;
            str = "Source:" + ex.Source;
            str += "
" + "Message:"+ ex.Message;
            str += "
" + "
";
            str += "
" + "Stack Trace :" + ex.StackTrace;
            Console.WriteLine (str, "Specific Exception");
         }
         catch (System.Data.SqlClient.SqlException ex)
         {
            string str;
            str = "Source:" + ex.Source;
            str += "
" + "Message:" + ex.Message;
            Console.WriteLine (str, "Database Exception");
         }
         catch (System.Exception ex)
         {
            string str;
            str = "Source:" + ex.Source;
            str += "
"+ "Message:" + ex.Message;
            Console.WriteLine (str, "Generic Exception");
         }
         finally
         {
            if ( conn.State == ConnectionState.Open)
            {
               Console.WriteLine ("Finally block closing the connection", "Finally");
               conn.Close();
            }
         }
      }
   }

SqlException message

Posted on by coder 
   



using System;
using System.Data;
using System.Data.SqlClient;

   class SqlExceptionDemo {
      static void Main(){
         string connString = "server=(local)SQLEXPRESS;database=MyDatabase;Integrated Security=SSPI";

         SqlConnection conn = new SqlConnection(connString);
         SqlCommand cmd = conn.CreateCommand(); 
  
         cmd.CommandType = CommandType.StoredProcedure;
  
         cmd.CommandText = "wrong sql";

         try{  
            conn.Open();
            SqlDataReader dr = cmd.ExecuteReader();    
            dr.Close();      
         } catch (System.Data.SqlClient.SqlException ex) {
            string str;
            str = "Source:" + ex.Source;
            str += "
" + "Exception Message:" + ex.Message;
            Console.WriteLine(str);
         }
         catch (System.Exception ex) 
         {
            string str;
            str = "Source:" + ex.Source;
            str += "
" + "Exception Message:" + ex.Message;
            Console.WriteLine(str);
         }
         finally
         {
            if (conn.State == ConnectionState.Open)
            {
               Console.WriteLine("Finally block closing the connection", "Finally");
               conn.Close();
            }   
         } 
      }
   }