using System;
using System.Data;
using System.Data.OleDb;
public class Create {
public static void Main () {
String connect = "Provider=Microsoft.JET.OLEDB.4.0;data source=.Employee.mdb";
OleDbConnection con = new OleDbConnection(connect);
con.Open();
OleDbCommand cmd = con.CreateCommand();
cmd.CommandText = "CREATE TABLE Customer (CustomerID "
+ "CHAR(4), CustomerName VARCHAR(25), Address "
+ "VARCHAR(25), BalanceDue DECIMAL)";
cmd.ExecuteNonQuery();
cmd.CommandText = "INSERT INTO Customer VALUES (1234,'F F','22 First St.',67.00)";
cmd.ExecuteNonQuery();
cmd.CommandText = "INSERT INTO Customer VALUES (5678,'D D','33 Second St.',130.95)";
cmd.ExecuteNonQuery();
cmd.CommandText = "INSERT INTO Customer VALUES (4321,'M M','44 Third St.',0)";
cmd.ExecuteNonQuery();
cmd.CommandText = "INSERT INTO Customer VALUES (8765,'C C','55 Fourth St.', 0)";
cmd.ExecuteNonQuery();
con.Close();
}
}
Delete database records through OleDbCommand and verify the results
using System;
using System.Data;
using System.Data.OleDb;
public class ExtractInfo {
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 Sales database");
OleDbCommand cmd = con.CreateCommand();
cmd.CommandText ="DELETE FROM Employee WHERE ID = 01";
cmd.ExecuteNonQuery();
cmd.CommandText = "SELECT First_Name FROM Employee";
OleDbDataReader reader = cmd.ExecuteReader();
Console.WriteLine();
while(reader.Read())
Console.WriteLine(reader.GetString(0));
reader.Close();
con.Close();
}
}
Between certain dates
using System;
using System.Data;
using System.Data.OleDb;
public class ExtractInfo {
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 Sales database");
OleDbCommand cmd = con.CreateCommand();
cmd.CommandText = "SELECT OrderNumber FROM Orders "
+ "WHERE OrderDate BETWEEN #4/1/99# AND #4/30/99#";
OleDbDataReader reader = cmd.ExecuteReader();
Console.WriteLine();
Console.WriteLine
(" Order numbers of orders from 4/1/99 to 4/30/99");
while(reader.Read())
Console.WriteLine(reader.GetString(0));
reader.Close();
con.Close();
}
}
Get count value from a select query
using System;
using System.Data;
using System.Data.OleDb;
public class DatabaseInfo {
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 command = con.CreateCommand();
command.CommandText = "SELECT COUNT(*) FROM Employee";
Console.WriteLine("Number of Employee rows: {0}",(int)command.ExecuteScalar());
con.Close();
}
}
Get max column value
using System;
using System.Data;
using System.Data.OleDb;
public class DatabaseInfo {
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 command = con.CreateCommand();
command.CommandText ="SELECT MAX(Salary) FROM Employee";
Console.WriteLine("Max of salary: {0:C}",(decimal)command.ExecuteScalar());
con.Close();
}
}
Get column average
using System;
using System.Data;
using System.Data.OleDb;
public class DatabaseInfo {
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 command = con.CreateCommand();
command.CommandText = "SELECT AVG(Salary) FROM Employee";
Console.WriteLine("Average of salary: {0:C}",(decimal)command.ExecuteScalar());
con.Close();
}
}
Execute aggregate function: sum
using System;
using System.Data;
using System.Data.OleDb;
public class DatabaseInfo {
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 command = con.CreateCommand();
command.CommandText ="SELECT SUM(salary) FROM Employee";
Console.WriteLine("Sum of salary: {0:C}",(decimal)command.ExecuteScalar());
con.Close();
}
}

