练习开发WPF程序的时候，是这样写的，虽然很简单，相必很多新手会用到，所以拿来共享一下，
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Configuration;
using System.Data.SqlClient;
using System.Data;
namespace HRMSys.DAL
{
static class SqlHelper
{
public static readonly string connstr = ConfigurationManager.ConnectionStrings["connstr"].ConnectionString;
public static int ExecuteNonQuery(string sql,
params SqlParameter[] parameters)
{
using (SqlConnection conn = new SqlConnection(connstr))
{
conn.Open();
using (SqlCommand cmd = conn.CreateCommand())
{
cmd.CommandText = sql;
cmd.Parameters.AddRange(parameters);
return cmd.ExecuteNonQuery();
}
}
}
public static object ExecuteScalar(string sql,
params SqlParameter[] parameters)
{
using (SqlConnection conn = new SqlConnection(connstr))
{
conn.Open();
using (SqlCommand cmd = conn.CreateCommand())
{
cmd.CommandText = sql;
cmd.Parameters.AddRange(parameters);
return cmd.ExecuteScalar();
}
}
}
public static DataTable ExecuteDataTable(string sql,
params SqlParameter[] parameters)
{
using (SqlConnection conn = new SqlConnection(connstr))
{
conn.Open();
using (SqlCommand cmd = conn.CreateCommand())
{
cmd.CommandText = sql;
cmd.Parameters.AddRange(parameters);
DataSet dataset = new DataSet();
SqlDataAdapter adapter = new SqlDataAdapter(cmd);
adapter.Fill(dataset);
return dataset.Tables[0];
}
}
}
public static object FromDbValue(object value)
{
if (value == DBNull.Value)
{
return null;
}
else
{
return value;
}
}
public static object ToDbValue(object value)
{
if (value == null)
{
return DBNull.Value;
}
else
{
return value;
}
}
}
}
在开发.net NVelocity小程序的时候，稍稍修改了一下
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Configuration;
using System.Data.SqlClient;
using System.Data;
namespace _06NVelocityCURD
{
public static class SqlHelper
{
public static readonly string connstr =
ConfigurationManager.ConnectionStrings["connstr"].ConnectionString;
public static SqlConnection OpenConnection()
{
SqlConnection conn = new SqlConnection(connstr);
conn.Open();
return conn;
}
public static int ExecuteNonQuery(string cmdText,
params SqlParameter[] parameters)
{
using (SqlConnection conn = new SqlConnection(connstr))
{
conn.Open();
return ExecuteNonQuery(conn, cmdText, parameters);
}
}
public static object ExecuteScalar(string cmdText,
params SqlParameter[] parameters)
{
using (SqlConnection conn = new SqlConnection(connstr))
{
conn.Open();
return ExecuteScalar(conn, cmdText, parameters);
}
}
public static DataTable ExecuteDataTable(string cmdText,
params SqlParameter[] parameters)
{
using (SqlConnection conn = new SqlConnection(connstr))
{
conn.Open();
return ExecuteDataTable(conn, cmdText, parameters);
}
}
public static int ExecuteNonQuery(SqlConnection conn,string cmdText,
params SqlParameter[] parameters)
{
using (SqlCommand cmd = conn.CreateCommand())
{
cmd.CommandText = cmdText;
cmd.Parameters.AddRange(parameters);
return cmd.ExecuteNonQuery();
}
}
public static object ExecuteScalar(SqlConnection conn, string cmdText,
params SqlParameter[] parameters)
{
using (SqlCommand cmd = conn.CreateCommand())
{
cmd.CommandText = cmdText;
cmd.Parameters.AddRange(parameters);
return cmd.ExecuteScalar();
}
}
public static DataTable ExecuteDataTable(SqlConnection conn, string cmdText,
params SqlParameter[] parameters)
{
using (SqlCommand cmd = conn.CreateCommand())
{
cmd.CommandText = cmdText;
cmd.Parameters.AddRange(parameters);
using (SqlDataAdapter adapter = new SqlDataAdapter(cmd))
{
DataTable dt = new DataTable();
adapter.Fill(dt);
return dt;
}
}
}
public static object ToDBValue(this object value)
{
return value == null ? DBNull.Value : value;
}
public static object FromDBValue(this object dbValue)
{
return dbValue == DBNull.Value ? null : dbValue;
}
}
}