ADO.NET通用类库

using System.Data;
using System.Data.SqlClient;

namespace DataService
{
   public class SQLHelper
    {
        public static readonly string connString = "Server=127.0.0.1;Database=WinFormDemo;uid=sa;pwd=123";

        #region ExecuteNonQuery
        /// <summary>
        /// 不带参数的ExcuteNonQuery
        /// </summary>
        public static int ExecuteNonQuery(string connString, CommandType cmdType, string cmdText)
        {
            SqlCommand cmd = new SqlCommand();
            cmd.CommandTimeout = ;
            using (SqlConnection conn = new SqlConnection(connString))
            {
                PrepareCommand(cmd, conn, (SqlTransaction)null, cmdType, cmdText, (SqlParameter[])null);
                int val = cmd.ExecuteNonQuery();
                return val;
            }
        }

        /// <summary>
        /// 带参数的ExcuteNonQuery
        /// </summary>
        public static int ExecuteNonQuery(string connString, CommandType cmdType, string cmdText, params SqlParameter[] cmdParms)
        {
            SqlCommand cmd = new SqlCommand();
            cmd.CommandTimeout = ;
            using (SqlConnection conn = new SqlConnection(connString))
            {
                PrepareCommand(cmd, conn, (SqlTransaction)null, cmdType, cmdText, cmdParms);
                int val = cmd.ExecuteNonQuery();
                cmd.Parameters.Clear();
                return val;

            }
        }
        #endregion ExecuteNonQuery

        #region ExecuteScalar
        /// <summary>
        /// 不带参数的ExecuteScalar
        /// </summary>
        public static object ExecuteScalar(string connString, CommandType cmdType, string cmdText)
        {
            SqlCommand cmd = new SqlCommand();
            cmd.CommandTimeout = ;
            using (SqlConnection conn = new SqlConnection(connString))
            {
                PrepareCommand(cmd, conn, (SqlTransaction)null, cmdType, cmdText, (SqlParameter[])null);
                object val = cmd.ExecuteScalar();
                return val;
            }
        }

        /// <summary>
        /// 带参数的ExecuteScalar
        /// </summary>
        public static object ExecuteScalar(string connString, CommandType cmdType, string cmdText, params SqlParameter[] cmdParms)
        {
            SqlCommand cmd = new SqlCommand();
            cmd.CommandTimeout = ;
            using (SqlConnection conn = new SqlConnection(connString))
            {
                PrepareCommand(cmd, conn, (SqlTransaction)null, cmdType, cmdText, cmdParms);
                object val = cmd.ExecuteScalar();
                cmd.Parameters.Clear();
                return val;
            }
        }
        #endregion ExecuteScalar

        #region ExecuteReader
        /// <summary>
        /// 不带参数的ExecuteReader
        /// </summary>
        public static SqlDataReader ExecuteReader(string connString, CommandType cmdType, string cmdText)
        {
            SqlCommand cmd = new SqlCommand();
            SqlConnection conn = new SqlConnection(connString);
            cmd.CommandTimeout = ;
            try
            {
                PrepareCommand(cmd, conn, (SqlTransaction)null, cmdType, cmdText, (SqlParameter[])null);
                SqlDataReader rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
                return rdr;
            }
            catch
            {
                conn.Close();
                throw;
            }
        }

        /// <summary>
        /// 带参数的ExecuteReader
        /// </summary>
        public static SqlDataReader ExecuteReader(string connString, CommandType cmdType, string cmdText, params SqlParameter[] cmdParms)
        {
            SqlCommand cmd = new SqlCommand();
            SqlConnection conn = new SqlConnection(connString);
            cmd.CommandTimeout = ;
            try
            {
                PrepareCommand(cmd, conn, (SqlTransaction)null, cmdType, cmdText, cmdParms);
                SqlDataReader rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
                cmd.Parameters.Clear();
                return rdr;
            }
            catch
            {
                conn.Close();
                throw;
            }
        }
        #endregion ExecuteReader

        #region ExecuteDataSet
        /// <summary>
        /// 不带参数的ExecuteDataSet,可以分页
        /// </summary>
        public static DataSet ExecuteDataset(string connString, CommandType cmdType, string cmdText)
        {
            SqlCommand cmd = new SqlCommand();
            cmd.CommandTimeout = ;
            using (SqlConnection conn = new SqlConnection(connString))
            {
                PrepareCommand(cmd, conn, (SqlTransaction)null, cmdType, cmdText, (SqlParameter[])null);
                SqlDataAdapter da = new SqlDataAdapter(cmd);
                DataSet ds = new DataSet();
                da.Fill(ds, "dtable");
                cmd.Parameters.Clear();
                return ds;
            }
        }

        /// <summary>
        /// 带参数的ExecuteDataSet,可以分页
        /// </summary>
        public static DataSet ExecuteDataset(string connString, CommandType cmdType, string cmdText, params SqlParameter[] cmdParms)
        {
            SqlCommand cmd = new SqlCommand();
            cmd.CommandTimeout = ;
            using (SqlConnection conn = new SqlConnection(connString))
            {
                PrepareCommand(cmd, conn, (SqlTransaction)null, cmdType, cmdText, cmdParms);
                SqlDataAdapter da = new SqlDataAdapter(cmd);
                DataSet ds = new DataSet();
                da.Fill(ds, "dtable");
                cmd.Parameters.Clear();
                return ds;
            }
        }
        #endregion ExecuteDataSet

        #region PrepareCommand
        /// <summary>
        /// 初始化工作
        /// </summary>
        private static void PrepareCommand(SqlCommand cmd, SqlConnection conn, SqlTransaction trans, CommandType cmdType, string cmdText, SqlParameter[] cmdParms)
        {

            if (conn.State != ConnectionState.Open)
                conn.Open();

            cmd.Connection = conn;
            cmd.CommandText = cmdText;

            if (trans != null)
                cmd.Transaction = trans;

            cmd.CommandType = cmdType;

            if (cmdParms != null)
            {
                foreach (SqlParameter parm in cmdParms)
                    cmd.Parameters.Add(parm);
            }
        }
        #endregion PrepareCommand
    }
}