自己写的一个SqlHelper：

namespace SQLHelper

{

class SqlHelper

{

private static string Connstr = ConfigurationManager.ConnectionStrings["dbConnStr"].ConnectionString;

#region 第一版

//public static int ExecuteNonQuery(string sql)

//{

// using (SqlConnection conn = new SqlConnection(Connstr))

// {

// conn.Open();

// using (SqlCommand cmd = conn.CreateCommand())

// {

// cmd.CommandText = sql;

// return cmd.ExecuteNonQuery();

// }

// }

//}

//public static object ExecuteScalar(string sql)

//{

// using (SqlConnection conn = new SqlConnection(Connstr))

// {

// conn.Open();

// using (SqlCommand cmd = conn.CreateCommand())

// {

// cmd.CommandText = sql;

// return cmd.ExecuteScalar();

// }

// }

//}

//public static DataTable ExecuteDataTable(string sql)

//{

// using (SqlConnection conn = new SqlConnection(Connstr))

// {

// conn.Open();

// using (SqlCommand cmd = conn.CreateCommand())

// {

// cmd.CommandText = sql;

// SqlDataAdapter adapter = new SqlDataAdapter(cmd);

// DataSet dataset = new DataSet();

// adapter.Fill(dataset);

// return dataset.Tables[0];

// }

// }

//}

#endregion

//将参数传进去且设为长度可变参数

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);

SqlDataAdapter adapter = new SqlDataAdapter(cmd);

DataSet dataset = new DataSet();

adapter.Fill(dataset);

return dataset.Tables[0];

}

}

}

}

}