Csharp/C Sharp by API/System.Data.OleDb/OleDbCommand
Содержание
new OleDbCommand(String SQL)
<source lang="csharp"> 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(); }
}
</source>
OleDbCommand.ExecuteNonQuery()
<source lang="csharp">
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(); }
}
</source>
OleDbCommand.ExecuteReader
<source lang="csharp"> 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(); }
}
</source>
OleDbCommand.ExecuteScalar
<source lang="csharp"> 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(); }
}
</source>
OleDbCommand.Transaction
<source lang="csharp"> 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(); }
}
</source>