Csharp/C Sharp by API/System.Data.OleDb/OleDbCommand
Содержание
new OleDbCommand(String SQL)
using System;
using System.Data;
using System.Data.OleDb;
class MainClass
{
[STAThread]
static void Main(string[] args)
{
string ConnectionString = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=c:\\Northwind.mdb";
string SQL = "SELECT * FROM Orders";
OleDbConnection conn = new OleDbConnection(ConnectionString);
OleDbCommand cmd = new OleDbCommand(SQL);
cmd.Connection = conn;
conn.Open();
OleDbDataReader reader = cmd.ExecuteReader();
while (reader.Read())
{
Console.Write("OrderID:"+reader.GetInt32(0).ToString() );
Console.Write(" ,");
Console.WriteLine("Customer:" + reader.GetString(1).ToString() );
}
reader.Close();
conn.Close();
}
}
OleDbCommand.ExecuteNonQuery()
using System;
using System.Data;
using System.Data.OleDb;
using System.Data.SqlClient;
class MainClass
{
static void Main(string[] args)
{
string ConnectionString = @"Provider=Microsoft.Jet.OLEDB.4.0; Data Source=c:\Northwind.mdb";
OleDbConnection conn = new OleDbConnection(ConnectionString);
conn.Open();
OleDbCommand cmd = new OleDbCommand("Customers", conn);
cmd.rumandText = @"DELETE * FROM Customers";
cmd.ExecuteNonQuery();
conn.Close();
}
}
OleDbCommand.ExecuteReader
using System;
using System.Data;
using System.Data.rumon;
using System.Data.OleDb;
class MainClass
{
static void Main(string[] args)
{
string connectionString = "Provider=Microsoft.JET.OLEDB.4.0;data source=C:\\Northwind.mdb";
OleDbConnection conn = new OleDbConnection(connectionString);
string sql = "SELECT * FROM Orders";
OleDbCommand cmd = new OleDbCommand(sql, conn);
conn.Open();
OleDbDataReader reader;
reader = cmd.ExecuteReader();
while (reader.Read())
{
Console.Write(reader.GetString(0).ToString() + " ," );
Console.Write(reader.GetString(1).ToString() + " ," );
Console.WriteLine("");
}
reader.Close();
conn.Close();
}
}
OleDbCommand.ExecuteScalar
using System;
using System.Data;
using System.Data.OleDb;
using System.Data.SqlClient;
class MainClass
{
static void Main(string[] args)
{
string ConnectionString = @"Provider=Microsoft.Jet.OLEDB.4.0; Data Source=c:\Northwind.mdb";
OleDbConnection conn = new OleDbConnection(ConnectionString);
conn.Open();
OleDbCommand cmd = new OleDbCommand();
cmd.rumandText = "SELECT Count(*) FROM Customers";
cmd.Connection = conn;
int counter = (int)cmd.ExecuteScalar();
Console.WriteLine("Total rows returned are :" + counter.ToString());
conn.Close();
}
}
OleDbCommand.Transaction
using System;
using System.Data;
using System.Data.OleDb;
public class Transact {
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();
OleDbTransaction trans = con.BeginTransaction();
cmd.Transaction = trans;
cmd.rumandText ="INSERT INTO Employee VALUES (09,"qwe","ewq",123)";
cmd.ExecuteNonQuery();
cmd.rumandText = "SELECT First_name FROM Employee";
OleDbDataReader reader = cmd.ExecuteReader();
while(reader.Read())
Console.WriteLine("{0}",
reader.GetString(0));
reader.Close();
con.Close();
}
}