using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Data.SqlClient;
using System.Linq;

namespace BLL
{
    public static class SqlBulkHelper
    {
        ///<summary>
        ///连接数据库
        ///</summary>
        ///<returns>返回SqlConnection对象</returns>
        public static SqlConnection GetCon()
        {
            return new SqlConnection(Funs.ConnString);
        }

        #region SqlBulkCopy批量插入数据
        /// <summary>
        /// 执行SqlBulkCopy批量插入，执行事务。
        /// </summary>
        /// <param name="connectionString">数据连接</param>
        /// <param name="TableName">表名</param>
        /// <param name="dt">要插入的数据</param>
        /// <returns></returns>
        public static int SqlBulkCopy(string connectionString, string TableName, DataTable dt)
        {
            using (SqlConnection conn = new SqlConnection(connectionString))
            {
                using (SqlBulkCopy sqlbulkcopy = new SqlBulkCopy(connectionString, SqlBulkCopyOptions.UseInternalTransaction))
                {
                    try
                    {
                        sqlbulkcopy.DestinationTableName = TableName;
                        for (int i = 0; i < dt.Columns.Count; i++)
                        {
                            sqlbulkcopy.ColumnMappings.Add(dt.Columns[i].ColumnName, dt.Columns[i].ColumnName);
                        }
                        sqlbulkcopy.WriteToServer(dt);
                        return 1;
                    }
                    catch (System.Exception ex)
                    {
                        return 0;
                    }
                }
            }
        }

        /// <summary>  
        /// 批量插入  
        /// </summary>  
        /// <typeparam name="T">泛型集合的类型</typeparam>  
        /// <param name="conn">连接对象</param>  
        /// <param name="tableName">将泛型集合插入到本地数据库表的表名</param>  
        /// <param name="list">要插入大泛型集合</param>  
        public static int BulkInsert<T>(SqlConnection conn, string tableName, IList<T> list)
        {
            int result = 0;

            try
            {
                if (conn.State != ConnectionState.Open)
                {
                    conn.Open(); //打开Connection连接  
                }
                using (var bulkCopy = new SqlBulkCopy(conn))
                {
                    bulkCopy.BatchSize = result = list.Count;
                    bulkCopy.DestinationTableName = tableName;
                    bulkCopy.BulkCopyTimeout = 600;
                    var table = new DataTable();
                    var props = TypeDescriptor.GetProperties(typeof(T)).Cast<PropertyDescriptor>().Where(propertyInfo => propertyInfo.PropertyType.Namespace.Equals("System")).ToArray();
                    foreach (var propertyInfo in props)
                    {
                        bulkCopy.ColumnMappings.Add(propertyInfo.Name, propertyInfo.Name);
                        table.Columns.Add(propertyInfo.Name, Nullable.GetUnderlyingType(propertyInfo.PropertyType) ?? propertyInfo.PropertyType);
                    }
                    var values = new object[props.Length];
                    foreach (var item in list)
                    {
                        for (var i = 0; i < values.Length; i++)
                        {
                            values[i] = props[i].GetValue(item);
                        }
                        table.Rows.Add(values);
                    }
                    bulkCopy.WriteToServer(table);
                }
                if (conn.State != ConnectionState.Closed)
                {
                    conn.Close(); //关闭Connection连接  
                }
            }
            catch (Exception ex)
            {
                result = 0;
            }

            return result;
        }
        #endregion

    }
}