SqlHelper

using System;
using System.Collections.Generic;
using System.Configuration;
using System.Data;
using System.Data.SqlClient;

namespace SmartLockerWS.Class
{
    /// <summary>
    /// https://www.cnblogs.com/694579350liuq/p/7080677.html
    /// OleDbConnection 支持连接sql、oracle、excel等多种数据源
    /// </summary>
    class sqlHelper1
    {
        public static string GetSqlConnectionString()
        {
            return ConfigurationManager.AppSettings["SQLConn"].ToString();
        }
       
        //适合增删改操作，返回影响条数
        public static int ExecuteNonQuery(string sql, params SqlParameter[] parameters)
        {
            using (SqlConnection conn = new SqlConnection(GetSqlConnectionString()))
            {
                using (SqlCommand comm = conn.CreateCommand())
                {
                    try
                    {
                        conn.Open();
                        comm.CommandText = sql;
                        if(parameters!=null)
                            comm.Parameters.AddRange(parameters);
                        return comm.ExecuteNonQuery();
                    }
                    catch (Exception ex)
                    {
                        throw new Exception(ex.Message);
                    }
                    finally
                    {
                        if (conn != null && conn.State != ConnectionState.Closed)
                            conn.Close();
                    }

                }
            }
        }
      
        //查询操作，返回查询结果中的第一行第一列的值
        public static object ExecuteScalar(string sql, params SqlParameter[] parameters)
        {
            using (SqlConnection conn = new SqlConnection(GetSqlConnectionString()))
            {
                using (SqlCommand comm = conn.CreateCommand())
                {
                    try
                    {
                        conn.Open();
                        comm.CommandText = sql;
                        if(parameters!=null)
                            comm.Parameters.AddRange(parameters);
                        return comm.ExecuteScalar();
                    }
                    catch (Exception ex)
                    {
                        throw new Exception(ex.Message);
                    }
                    finally
                    {
                        if (conn != null && conn.State != ConnectionState.Closed)
                            conn.Close();
                    }
                }
            }
        }
       
        //Adapter调整，查询操作，返回DataTable
        public static DataTable ExecuteDataTable(string sql, params SqlParameter[] parameters)
        {

            using (SqlDataAdapter adapter = new SqlDataAdapter(sql, GetSqlConnectionString()))
            {
                DataTable dt = new DataTable();
                if(parameters!=null)
                    adapter.SelectCommand.Parameters.AddRange(parameters);
                adapter.Fill(dt);
                return dt;
            }
        }

        //dataset
        public static DataSet ExecuteDataset(string sql, params SqlParameter[] parameters)
        {
            using (SqlDataAdapter adapter = new SqlDataAdapter(sql, GetSqlConnectionString()))
            {
                DataSet ds = new DataSet();
                if(parameters!=null)
                    adapter.SelectCommand.Parameters.AddRange(parameters);
                adapter.Fill(ds);
                return ds;
                ////表集合
                //DataTableCollection table = ds.Tables;
            }
        }

        //datareader
        public static SqlDataReader ExecuteReader(string sqlText, params SqlParameter[] parameters)
        {
            //SqlDataReader要求，它读取数据的时候有，它独占它的SqlConnection对象，而且SqlConnection必须是Open状态
            SqlConnection conn = new SqlConnection(GetSqlConnectionString());//不要释放连接，因为后面还需要连接打开状态
            SqlCommand cmd = conn.CreateCommand();
            conn.Open();
            cmd.CommandText = sqlText;
            if(parameters!=null)
                cmd.Parameters.AddRange(parameters);
            //CommandBehavior.CloseConnection当SqlDataReader释放的时候，顺便把SqlConnection对象也释放掉
            return cmd.ExecuteReader(CommandBehavior.CloseConnection);
        }

      
        /// <summary> 
        /// 执行多条SQL语句，实现数据库事务。 
        /// </summary> 
        /// <param name="SQLStringList">多条SQL语句</param>      
        public static int ExecuteSqlTran(List<String> SQLStringList)
        {
            using (SqlConnection conn = new SqlConnection(GetSqlConnectionString()))
            {
                conn.Open();
                SqlCommand cmd = new SqlCommand();
                cmd.Connection = conn;
                SqlTransaction tx = conn.BeginTransaction();
                cmd.Transaction = tx;
                try
                {
                    int count = 0;
                    for (int n = 0; n < SQLStringList.Count; n++)
                    {
                        string strsql = SQLStringList[n];
                        if (strsql.Trim().Length > 1)
                        {
                            cmd.CommandText = strsql;
                            count += cmd.ExecuteNonQuery();
                        }
                    }
                    tx.Commit();
                    return count;
                }
                catch
                {
                    tx.Rollback();
                    return 0;
                }
            }
        }

        /// <summary> 
        /// 执行存储过程，返回SqlDataReader ( 注意：调用该方法后，一定要对SqlDataReader进行Close ) 
        /// </summary> 
        /// <param name="storedProcName">存储过程名</param> 
        /// <param name="parameters">存储过程参数</param> 
        /// <returns>SqlDataReader</returns> 
        public static SqlDataReader RunProcedure(string storedProcName, IDataParameter[] parameters)
        {
            SqlConnection connection = new SqlConnection(GetSqlConnectionString());
            SqlDataReader returnReader;
            connection.Open();
            SqlCommand command = BuildQueryCommand(connection, storedProcName, parameters);
            command.CommandType = CommandType.StoredProcedure;
            returnReader = command.ExecuteReader(CommandBehavior.CloseConnection);
            return returnReader;

        }
        private static SqlCommand BuildQueryCommand(SqlConnection connection, string storedProcName, IDataParameter[] parameters)
        {
            SqlCommand command = new SqlCommand(storedProcName, connection);
            command.CommandType = CommandType.StoredProcedure;
            foreach (SqlParameter parameter in parameters)
            {
                if (parameter != null)
                {
                    // 检查未分配值的输出参数,将其分配以DBNull.Value. 
                    if ((parameter.Direction == ParameterDirection.InputOutput || parameter.Direction == ParameterDirection.Input) &&
                        (parameter.Value == null))
                    {
                        parameter.Value = DBNull.Value;
                    }
                    command.Parameters.Add(parameter);
                }
            }

            return command;
        }

    }

}