29 Mar

Select,Insert,Update,Delete Data in Access File using C#

This example shows how to insert ,update, delete and select data in Access File(CRUD Operations).

TABLE1:

ID NAME SURNAME
1 Jack Sparrow

Select Command Example:

            
            string mdfFile = @"csharpexamples.mdb";

            using (OleDbConnection connection = new OleDbConnection(string.Format("Provider=Microsoft.Jet.OLEDB.4.0;Data Source={0}", mdfFile)))
            {
                using (OleDbCommand selectCommand = new OleDbCommand("SELECT TOP 10 * FROM TABLE1", connection))
                {
                    connection.Open();

                    DataTable table = new DataTable();
                    OleDbDataAdapter adapter = new OleDbDataAdapter();
                    adapter.SelectCommand = selectCommand;
                    adapter.Fill(table);

                    foreach (DataRow row in table.Rows)
                    {
                        object nameValue = row["NAME"];
                        object surnameValue = row["SURNAME"];
                    }
                }
            }

Insert Command Example:

            
            string mdfFile = @"csharpexamples.mdb";

            using (OleDbConnection connection = new OleDbConnection(string.Format("Provider=Microsoft.Jet.OLEDB.4.0;Data Source={0}", mdfFile)))
            {
                using (OleDbCommand insertCommand = new OleDbCommand("INSERT INTO TABLE1 ([NAME],[SURNAME]) VALUES (?,?)", connection))
                {
                    connection.Open();

                    insertCommand.Parameters.AddWithValue("@NAME", "Brad");
                    insertCommand.Parameters.AddWithValue("@SURNAME", "Pitt");

                    insertCommand.ExecuteNonQuery();
                }
            }

Update Command Example:

      
            string mdfFile = @"csharpexamples.mdb";

            using (OleDbConnection connection = new OleDbConnection(string.Format("Provider=Microsoft.Jet.OLEDB.4.0;Data Source={0}", mdfFile)))
            {
                using (OleDbCommand updateCommand = new OleDbCommand("UPDATE TABLE1 SET [NAME] = ?, [SURNAME] = ? WHERE [ID] = ?", connection))
                {
                    connection.Open();

                    updateCommand.Parameters.AddWithValue("@NAME", "Brad2");
                    updateCommand.Parameters.AddWithValue("@SURNAME", "Pitt2");
                    updateCommand.Parameters.AddWithValue("@ID", 2);

                    updateCommand.ExecuteNonQuery();
                }
            }      

Delete Command Example:

            
            string mdfFile = @"csharpexamples.mdb";

            using (OleDbConnection connection = new OleDbConnection(string.Format("Provider=Microsoft.Jet.OLEDB.4.0;Data Source={0}", mdfFile)))
            {
                using (OleDbCommand deleteCommand = new OleDbCommand("DELETE FROM TABLE1 WHERE [ID] = ?", connection))
                {
                    connection.Open();

                    deleteCommand.Parameters.AddWithValue("@ID", 2);

                    deleteCommand.ExecuteNonQuery();
                }
            }

See Also: Select,Insert,Update,Delete Data in MySQL using C#

27 Mar

C# ArrayList Example

The ArrayList is similar to the C# array data type. The greatest difference is the dynamic nature of the collection of array list.

  • The add method is used to add an element to the ArrayList.

ArrayList Example:

ArrayList arrayList = new ArrayList();
arrayList.Add("Element 1");
arrayList.Add("Element 2");
arrayList.Add("Element 3");

Console.WriteLine("ArrayList Count: " + arrayList.Count);
Console.WriteLine("Contains Element2: " + arrayList.Contains("Element 2"));
arrayList.Remove("Element 2");
Console.WriteLine("ArrayList Count: " + arrayList.Count);

Program Output:
array list output

27 Mar

C# Stack Example

The stack represents a simple last-in-first-out (LIFO) non-generic collection of objects.

  • To add an element to the stack, the push method is used. The statement’s general syntax is shown below:
stack.Push("Obj");
  • To remove an element from the stack, the pop method is used. The pop operation returns the stack’s top element. The statement’s general syntax is given below:
object popObj = stack.Pop();

Stack Example:

            Stack stack = new Stack();
            stack.Push("Obj1");
            stack.Push("Obj2");
            stack.Push("Obj3");

            Console.WriteLine("Objects");
            Console.WriteLine("-------");
            foreach (Object obj in stack)
            {
                Console.WriteLine(obj);
            }
            object popObj = stack.Pop();
            Console.WriteLine("Last In/First Out(LIFO): " + popObj);

            Console.WriteLine("The number of elements in the stack: " + stack.Count);
            Console.WriteLine("Contains Obj1:  " + stack.Contains("Obj1"));

Program Output:

stack output

27 Mar

C# Queue Example

The Queue is a special collection which represents first-in, first-out concept of objects.

  • An element is added to the queue using the enqueue method. The statement’s general syntax is shown below:
queue.Enqueue("Obj");
  • To remove an element from the queue, the dequeue method is used. The dequeue operat on returns the queue’s last element. The statement’s general syntax is given below:
object obj = queue.Dequeue();

 

Queue Example:

Queue queue = new Queue();
queue.Enqueue("Obj1");
queue.Enqueue("Obj2");
queue.Enqueue("Obj3");

Console.WriteLine("The number of elements in the Queue: " + queue.Count);
Console.WriteLine("All objects");
foreach (Object obj in queue)
{
     Console.WriteLine(obj);
}

object obj1 = queue.Dequeue();
Console.WriteLine("First: " + obj1);

Console.WriteLine("Contains Obj1: " + queue.Contains("Obj1"));
Console.WriteLine("Contains Obj2: " + queue.Contains("Obj2"));

Program Output:
queue output

27 Mar

C# Hashtable Example

A hash table is a collection that is used to store key-value pairs. So the hash table stores 2 values while storing just one value like the stack, array list and queue. These 2 values are an element of the hash table.

  • To add an element to the queue, the Add method is used. The statement’s general syntax is given below.
ht.Add("key", "Value");
  • ContainsKey method is used to determine whether the Hashtable contains a specific key.
  • ContainsValue method is used to determine whether the Hashtable contains a specific value.

When you use foreach to enumerate hash table elements, the elements are retrieved as KeyValuePair objects.

            foreach (DictionaryEntry de in ht)
            {
                Console.WriteLine("Key = {0}, Value = {1}", de.Key, de.Value);
            }

Hastable Example:

            
            Hashtable ht = new Hashtable();
            
            // Add key-value pairs
            ht.Add("key1", "Value1");
            ht.Add("key2", "Value2");
            ht.Add("key3", "Value3");

            bool hasKey1 = ht.ContainsKey("key1");
            bool hasValue2 = ht.ContainsValue("Value1");

            // When you use foreach to enumerate hash table elements,
            // the elements are retrieved as KeyValuePair objects.
            foreach (DictionaryEntry de in ht)
            {
                Console.WriteLine("Key = {0}, Value = {1}", de.Key, de.Value);
            }

Program Output:
hashtable output