sql server批量导出数据（SQL Server 批量插入数据的完美解决方案）

public static void Insert(IEnumerable<Person> persons)
{
  using (var con = new SqlConnection("Server=.;Database=DemoDataBase;User ID=sa;Password=8888;"))
  {
    con.Open();
    foreach (var person in persons)
    {
      using (var com = new SqlCommand(
        "INSERT INTO dbo.Person(Id,Name,Age,CreateTime,Sex)VALUES(@Id,@Name,@Age,@CreateTime,@Sex)",
        con))
      {
        com.Parameters.AddRange(new[]
        {
          new SqlParameter("@Id", SqlDbType.BigInt) {Value = person.Id},
          new SqlParameter("@Name", SqlDbType.VarChar, 64) {Value = person.Name},
          new SqlParameter("@Age", SqlDbType.Int) {Value = person.Age},
          new SqlParameter("@CreateTime", SqlDbType.DateTime)
            {Value = person.CreateTime ?? (object) DBNull.Value},
          new SqlParameter("@Sex", SqlDbType.Int) {Value = (int)person.Sex},
        });
        com.ExecuteNonQuery();
      }
    }
  }
}

public static void BatchInsert(Person[] persons)
{
  using (var con = new SqlConnection("Server=.;Database=DemoDataBase;User ID=sa;Password=8888;"))
  {
    con.Open();
    var pageCount = (persons.Length - 1) / 1000 + 1;
    for (int i = 0; i < pageCount; i++)
    {
      var personList = persons.Skip(i * 1000).Take(1000).ToArray();
      var values = personList.Select(p =>
        $"({p.Id},'{p.Name}',{p.Age},{(p.CreateTime.HasValue ? $"'{p.CreateTime:yyyy-MM-dd HH:mm:ss}'" : "NULL")},{(int) p.Sex})");
      var insertSql =
        $"INSERT INTO dbo.Person(Id,Name,Age,CreateTime,Sex)VALUES{string.Join(",", values)}";
      using (var com = new SqlCommand(insertSql, con))
      {
        com.ExecuteNonQuery();
      }
    }
  }
}

public static void BulkCopy(IEnumerable<Person> persons)
{
  using (var con = new SqlConnection("Server=.;Database=DemoDataBase;User ID=sa;Password=8888;"))
  {
    con.Open();
    var table = new DataTable();
    table.Columns.AddRange(new []
    {
      new DataColumn("Id", typeof(long)), 
      new DataColumn("Name", typeof(string)), 
      new DataColumn("Age", typeof(int)), 
      new DataColumn("CreateTime", typeof(DateTime)), 
      new DataColumn("Sex", typeof(int)), 
    });
    foreach (var p in persons)
    {
      table.Rows.Add(new object[] {p.Id, p.Name, p.Age, p.CreateTime, (int) p.Sex});
    }

    using (var copy = new SqlBulkCopy(con))
    {
      copy.DestinationTableName = "Person";
      copy.WriteToServer(table);
    }
  }
}

CREATE TABLE [dbo].[Person](
	[Id] [BIGINT] NOT NULL,
	[Name] [VARCHAR](64) NOT NULL,
	[Age] [INT] NOT NULL,
	[CreateTime] [DATETIME] NULL,
	[Sex] [INT] NOT NULL,
PRIMARY KEY CLUSTERED 
(
	[Id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]

public class Person
{
  public long Id { get; set; }
  public string Name { get; set; }
  public int Age { get; set; }
  public DateTime? CreateTime { get; set; }
  public Gender Sex { get; set; }
}

public enum Gender
{
  Man = 0,
  Woman = 1
}

//创建批量插入对象
using (var copy = new SqlBulkCopy(connection, options, externalTransaction))
{
  foreach (var column in ModelToDataTable<TModel>.Columns)
  {
    //创建字段映射
    copy.ColumnMappings.Add(column.ColumnName, column.ColumnName);
  }
}

 public static class SqlConnectionExtension
  {
    /// <summary>
    /// 批量复制
    /// </summary>
    /// <typeparam name="TModel">插入的模型对象</typeparam>
    /// <param name="source">需要批量插入的数据源</param>
    /// <param name="connection">数据库连接对象</param>
    /// <param name="tableName">插入表名称【为NULL默认为实体名称】</param>
    /// <param name="bulkCopyTimeout">插入超时时间</param>
    /// <param name="batchSize">写入数据库一批数量【如果为0代表全部一次性插入】最合适数量【这取决于您的环境，尤其是行数和网络延迟。就个人而言，我将从BatchSize属性设置为1000行开始，然后看看其性能如何。如果可行，那么我将使行数加倍（例如增加到2000、4000等），直到性能下降或超时。否则，如果超时发生在1000，那么我将行数减少一半（例如500），直到它起作用为止。】</param>
    /// <param name="options">批量复制参数</param>
    /// <param name="externalTransaction">执行的事务对象</param>
    /// <returns>插入数量</returns>
    public static int BulkCopy<TModel>(this SqlConnection connection,
      IEnumerable<TModel> source,
      string tableName = null,
      int bulkCopyTimeout = 30,
      int batchSize = 0,
      SqlBulkCopyOptions options = SqlBulkCopyOptions.Default,
      SqlTransaction externalTransaction = null)
    {
      //创建读取器
      using (var reader = new EnumerableReader<TModel>(source))
      {
        //创建批量插入对象
        using (var copy = new SqlBulkCopy(connection, options, externalTransaction))
        {
          //插入的表
          copy.DestinationTableName = tableName ?? typeof(TModel).Name;
          //写入数据库一批数量
          copy.BatchSize = batchSize;
          //超时时间
          copy.BulkCopyTimeout = bulkCopyTimeout;
          //创建字段映射【如果没有此字段映射会导致数据填错位置，如果类型不对还会导致报错】【因为：没有此字段映射默认是按照列序号对应插入的】
          foreach (var column in ModelToDataTable<TModel>.Columns)
          {
            //创建字段映射
            copy.ColumnMappings.Add(column.ColumnName, column.ColumnName);
          }
          //将数据批量写入数据库
          copy.WriteToServer(reader);
          //返回插入数据数量
          return reader.Depth;
        }
      }
    }

    /// <summary>
    /// 批量复制-异步
    /// </summary>
    /// <typeparam name="TModel">插入的模型对象</typeparam>
    /// <param name="source">需要批量插入的数据源</param>
    /// <param name="connection">数据库连接对象</param>
    /// <param name="tableName">插入表名称【为NULL默认为实体名称】</param>
    /// <param name="bulkCopyTimeout">插入超时时间</param>
    /// <param name="batchSize">写入数据库一批数量【如果为0代表全部一次性插入】最合适数量【这取决于您的环境，尤其是行数和网络延迟。就个人而言，我将从BatchSize属性设置为1000行开始，然后看看其性能如何。如果可行，那么我将使行数加倍（例如增加到2000、4000等），直到性能下降或超时。否则，如果超时发生在1000，那么我将行数减少一半（例如500），直到它起作用为止。】</param>
    /// <param name="options">批量复制参数</param>
    /// <param name="externalTransaction">执行的事务对象</param>
    /// <returns>插入数量</returns>
    public static async Task<int> BulkCopyAsync<TModel>(this SqlConnection connection,
      IEnumerable<TModel> source,
      string tableName = null,
      int bulkCopyTimeout = 30,
      int batchSize = 0,
      SqlBulkCopyOptions options = SqlBulkCopyOptions.Default,
      SqlTransaction externalTransaction = null)
    {
      //创建读取器
      using (var reader = new EnumerableReader<TModel>(source))
      {
        //创建批量插入对象
        using (var copy = new SqlBulkCopy(connection, options, externalTransaction))
        {
          //插入的表
          copy.DestinationTableName = tableName ?? typeof(TModel).Name;
          //写入数据库一批数量
          copy.BatchSize = batchSize;
          //超时时间
          copy.BulkCopyTimeout = bulkCopyTimeout;
          //创建字段映射【如果没有此字段映射会导致数据填错位置，如果类型不对还会导致报错】【因为：没有此字段映射默认是按照列序号对应插入的】
          foreach (var column in ModelToDataTable<TModel>.Columns)
          {
            //创建字段映射
            copy.ColumnMappings.Add(column.ColumnName, column.ColumnName);
          }
          //将数据批量写入数据库
          await copy.WriteToServerAsync(reader);
          //返回插入数据数量
          return reader.Depth;
        }
      }
    }
  }

 /// <summary>
  /// 迭代器数据读取器
  /// </summary>
  /// <typeparam name="TModel">模型类型</typeparam>
  public class EnumerableReader<TModel> : IDataReader
  {
    /// <summary>
    /// 实例化迭代器读取对象
    /// </summary>
    /// <param name="source">模型源</param>
    public EnumerableReader(IEnumerable<TModel> source)
    {
      _source = source ?? throw new ArgumentNullException(nameof(source));
      _enumerable = source.GetEnumerator();
    }

    private readonly IEnumerable<TModel> _source;
    private readonly IEnumerator<TModel> _enumerable;
    private object[] _currentDataRow = Array.Empty<object>();
    private int _depth;
    private bool _release;

    public void Dispose()
    {
      _release = true;
      _enumerable.Dispose();
    }

    public int GetValues(object[] values)
    {
      if (values == null) throw new ArgumentNullException(nameof(values));
      var length = Math.Min(_currentDataRow.Length, values.Length);
      Array.Copy(_currentDataRow, values, length);
      return length;
    }

    public int GetOrdinal(string name)
    {
      for (int i = 0; i < ModelToDataTable<TModel>.Columns.Count; i++)
      {
        if (ModelToDataTable<TModel>.Columns[i].ColumnName == name) return i;
      }

      return -1;
    }

    public long GetBytes(int ordinal, long dataIndex, byte[] buffer, int bufferIndex, int length)
    {
      if (dataIndex < 0) throw new Exception($"起始下标不能小于0！");
      if (bufferIndex < 0) throw new Exception("目标缓冲区起始下标不能小于0！");
      if (length < 0) throw new Exception("读取长度不能小于0！");
      var numArray = (byte[])GetValue(ordinal);
      if (buffer == null) return numArray.Length;
      if (buffer.Length <= bufferIndex) throw new Exception("目标缓冲区起始下标不能大于目标缓冲区范围！");
      var freeLength = Math.Min(numArray.Length - bufferIndex, length);
      if (freeLength <= 0) return 0;
      Array.Copy(numArray, dataIndex, buffer, bufferIndex, length);
      return freeLength;
    }

    public long GetChars(int ordinal, long dataIndex, char[] buffer, int bufferIndex, int length)
    {
      if (dataIndex < 0) throw new Exception($"起始下标不能小于0！");
      if (bufferIndex < 0) throw new Exception("目标缓冲区起始下标不能小于0！");
      if (length < 0) throw new Exception("读取长度不能小于0！");
      var numArray = (char[])GetValue(ordinal);
      if (buffer == null) return numArray.Length;
      if (buffer.Length <= bufferIndex) throw new Exception("目标缓冲区起始下标不能大于目标缓冲区范围！");
      var freeLength = Math.Min(numArray.Length - bufferIndex, length);
      if (freeLength <= 0) return 0;
      Array.Copy(numArray, dataIndex, buffer, bufferIndex, length);
      return freeLength;
    }

    public bool IsDBNull(int i)
    {
      var value = GetValue(i);
      return value == null || value is DBNull;
    }
    public bool NextResult()
    {
      //移动到下一个元素
      if (!_enumerable.MoveNext()) return false;
      //行层+1
      Interlocked.Increment(ref _depth);
      //得到数据行
      _currentDataRow = ModelToDataTable<TModel>.ToRowData.Invoke(_enumerable.Current);
      return true;
    }

    public byte GetByte(int i) => (byte)GetValue(i);
    public string GetName(int i) => ModelToDataTable<TModel>.Columns[i].ColumnName;
    public string GetDataTypeName(int i) => ModelToDataTable<TModel>.Columns[i].DataType.Name;
    public Type GetFieldType(int i) => ModelToDataTable<TModel>.Columns[i].DataType;
    public object GetValue(int i) => _currentDataRow[i];
    public bool GetBoolean(int i) => (bool)GetValue(i);
    public char GetChar(int i) => (char)GetValue(i);
    public Guid GetGuid(int i) => (Guid)GetValue(i);
    public short GetInt16(int i) => (short)GetValue(i);
    public int GetInt32(int i) => (int)GetValue(i);
    public long GetInt64(int i) => (long)GetValue(i);
    public float GetFloat(int i) => (float)GetValue(i);
    public double GetDouble(int i) => (double)GetValue(i);
    public string GetString(int i) => (string)GetValue(i);
    public decimal GetDecimal(int i) => (decimal)GetValue(i);
    public DateTime GetDateTime(int i) => (DateTime)GetValue(i);
    public IDataReader GetData(int i) => throw new NotSupportedException();
    public int FieldCount => ModelToDataTable<TModel>.Columns.Count;
    public object this[int i] => GetValue(i);
    public object this[string name] => GetValue(GetOrdinal(name));
    public void Close() => Dispose();
    public DataTable GetSchemaTable() => ModelToDataTable<TModel>.ToDataTable(_source);
    public bool Read() => NextResult();
    public int Depth => _depth;
    public bool IsClosed => _release;
    public int RecordsAffected => 0;
  }

/// <summary>
  /// 对象转换成DataTable转换类
  /// </summary>
  /// <typeparam name="TModel">泛型类型</typeparam>
  public static class ModelToDataTable<TModel>
  {
    static ModelToDataTable()
    {
      //如果需要剔除某些列可以修改这段代码
      var propertyList = typeof(TModel).GetProperties().Where(w => w.CanRead).ToArray();
      Columns = new ReadOnlyCollection<DataColumn>(propertyList
        .Select(pr => new DataColumn(pr.Name, GetDataType(pr.PropertyType))).ToArray());
      //生成对象转数据行委托
      ToRowData = BuildToRowDataDelegation(typeof(TModel), propertyList);
    }

    /// <summary>
    /// 构建转换成数据行委托
    /// </summary>
    /// <param name="type">传入类型</param>
    /// <param name="propertyList">转换的属性</param>
    /// <returns>转换数据行委托</returns>
    private static Func<TModel, object[]> BuildToRowDataDelegation(Type type, PropertyInfo[] propertyList)
    {
      var source = Expression.Parameter(type);
      var items = propertyList.Select(property => ConvertBindPropertyToData(source, property));
      var array = Expression.NewArrayInit(typeof(object), items);
      var lambda = Expression.Lambda<Func<TModel, object[]>>(array, source);
      return lambda.Compile();
    }

    /// <summary>
    /// 将属性转换成数据
    /// </summary>
    /// <param name="source">源变量</param>
    /// <param name="property">属性信息</param>
    /// <returns>获取属性数据表达式</returns>
    private static Expression ConvertBindPropertyToData(ParameterExpression source, PropertyInfo property)
    {
      var propertyType = property.PropertyType;
      var expression = (Expression)Expression.Property(source, property);
      if (propertyType.IsEnum)
        expression = Expression.Convert(expression, propertyType.GetEnumUnderlyingType());
      return Expression.Convert(expression, typeof(object));
    }

    /// <summary>
    /// 获取数据类型
    /// </summary>
    /// <param name="type">属性类型</param>
    /// <returns>数据类型</returns>
    private static Type GetDataType(Type type)
    {
      //枚举默认转换成对应的值类型
      if (type.IsEnum)
        return type.GetEnumUnderlyingType();
      //可空类型
      if (type.IsGenericType && type.GetGenericTypeDefinition() == typeof(Nullable<>))
        return GetDataType(type.GetGenericArguments().First());
      return type;
    }

    /// <summary>
    /// 列集合
    /// </summary>
    public static IReadOnlyList<DataColumn> Columns { get; }

    /// <summary>
    /// 对象转数据行委托
    /// </summary>
    public static Func<TModel, object[]> ToRowData { get; }

    /// <summary>
    /// 集合转换成DataTable
    /// </summary>
    /// <param name="source">集合</param>
    /// <param name="tableName">表名称</param>
    /// <returns>转换完成的DataTable</returns>
    public static DataTable ToDataTable(IEnumerable<TModel> source, string tableName = "TempTable")
    {
      //创建表对象
      var table = new DataTable(tableName);
      //设置列
      foreach (var dataColumn in Columns)
      {
        table.Columns.Add(new DataColumn(dataColumn.ColumnName, dataColumn.DataType));
      }

      //循环转换每一行数据
      foreach (var item in source)
      {
        table.Rows.Add(ToRowData.Invoke(item));
      }

      //返回表对象
      return table;
    }
  }

CREATE TABLE [dbo].[Person](
	[Id] [BIGINT] NOT NULL,
	[Name] [VARCHAR](64) NOT NULL,
	[Age] [INT] NOT NULL,
	[CreateTime] [DATETIME] NULL,
	[Sex] [INT] NOT NULL,
PRIMARY KEY CLUSTERED 
(
	[Id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]

public class Person
{
  public long Id { get; set; }
  public string Name { get; set; }
  public int Age { get; set; }
  public DateTime? CreateTime { get; set; }
  public Gender Sex { get; set; }
}

public enum Gender
{
  Man = 0,
  Woman = 1
}

//生成10万条数据
var persons = new Person[100000];
var random = new Random();
for (int i = 0; i < persons.Length; i++)
{
  persons[i] = new Person
  {
    Id = i + 1,
    Name = "张三" + i,
    Age = random.Next(1, 128),
    Sex = (Gender)random.Next(2),
    CreateTime = random.Next(2) == 0 ? null : (DateTime?) DateTime.Now.AddSeconds(i)
  };
}

//创建数据库连接
using (var conn = new SqlConnection("Server=.;Database=DemoDataBase;User ID=sa;Password=8888;"))
{
  conn.Open();
  var sw = Stopwatch.StartNew();
  //批量插入数据
  var qty = conn.BulkCopy(persons);
  sw.Stop();
  Console.WriteLine(sw.Elapsed.TotalMilliseconds + "ms");
}