C# 封装SqlBulkCopy,让批量插入更方便

时间:2024-08-19 13:33:44

关于 SqlServer 批量插入的方式,前段时间也有大神给出了好几种批量插入的方式及对比测试(http://www.cnblogs.com/jiekzou/p/6145550.html),估计大家也都明白,最佳的方式就是用 SqlBulkCopy。我对 SqlBulkCopy 封装成了一个 Helper 方法,使得批量插入更加方便,先看看封装后的方法定义:

public static class SqlConnectionExtension
{
/// <summary>
/// 使用 SqlBulkCopy 向 destinationTableName 表插入数据
/// </summary>
/// <typeparam name="TModel">必须拥有与目标表所有字段对应属性</typeparam>
/// <param name="conn"></param>
/// <param name="modelList">要插入的数据</param>
/// <param name="batchSize">SqlBulkCopy.BatchSize</param>
/// <param name="destinationTableName">如果为 null,则使用 TModel 名称作为 destinationTableName</param>
/// <param name="bulkCopyTimeout">SqlBulkCopy.BulkCopyTimeout</param>
/// <param name="externalTransaction">要使用的事务</param>
public static void BulkCopy<TModel>(this SqlConnection conn, List<TModel> modelList, int batchSize, string destinationTableName = null, int? bulkCopyTimeout = null, SqlTransaction externalTransaction = null);
}

上面都有详细解释,相信大家一看就会明白,接下来演示下用法及效果:

先创建一个测试的 Users 表:

CREATE TABLE [dbo].[Users](
[Id] [uniqueidentifier] NOT NULL,
[Name] [nvarchar](100) NULL,
[Gender] [int] NULL,
[Age] [int] NULL,
[CityId] [int] NULL,
[OpTime] [datetime] NULL,
CONSTRAINT [PK_Users] 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]

然后定义一个与表映射的 Model,记住,由于 SqlBulkCopy 的特性,定义的 Model 必须拥有与表所有的字段对应的属性:

public enum Gender
{
Man = ,
Woman
} public class User
{
public Guid Id { get; set; }
public string Name { get; set; }
public Gender? Gender { get; set; }
public int? Age { get; set; }
public int? CityId { get; set; }
public DateTime? OpTime { get; set; }
}

制造些数据,然后就可以直接插入了:

List<User> usersToInsert = new List<User>();
usersToInsert.Add(new User() { Id = Guid.NewGuid(), Name = "so1", Gender = Gender.Man, Age = , CityId = , OpTime = DateTime.Now });
usersToInsert.Add(new User() { Id = Guid.NewGuid(), Name = "so2", Gender = Gender.Man, Age = , CityId = , OpTime = DateTime.Now });
usersToInsert.Add(new User() { Id = Guid.NewGuid(), Name = "so3", Gender = Gender.Man, Age = , CityId = , OpTime = DateTime.Now });
usersToInsert.Add(new User() { Id = Guid.NewGuid(), Name = "so4", Gender = Gender.Man, Age = , CityId = , OpTime = DateTime.Now }); using (SqlConnection conn = new SqlConnection("Data Source = .;Initial Catalog = Chloe;Integrated Security = SSPI;"))
{
conn.BulkCopy(usersToInsert, , "Users");
}

执行插入后表数据:

C# 封装SqlBulkCopy,让批量插入更方便

很方便吧,定义好 Model,调用 BulkCopy 方法就能插入了。这个方法主要解决了两个问题:1.免去手动构造 DataTable 和向 DataTable 填充数据,要知道,SqlBulkCopy 要求 DataTable 的列必须和表列顺序一致,如果手动构造 DataTable 的话会使代码很难维护;2.不用亲自 new 出 SqlBulkCopy 对象以及手动给 SqlBulkCopy 对象设置各种值,如 DestinationTableName、BulkCopyTimeout、BatchSize 等,用封装的方法,直接传相应的值就好了。接下来贴干货,简单介绍下实现。

先了解 SqlBulkCopy 的定义(部分):

public sealed class SqlBulkCopy : IDisposable
{
public SqlBulkCopy(SqlConnection connection);
public SqlBulkCopy(string connectionString);
public SqlBulkCopy(string connectionString, SqlBulkCopyOptions copyOptions);
public SqlBulkCopy(SqlConnection connection, SqlBulkCopyOptions copyOptions, SqlTransaction externalTransaction); public int BatchSize { get; set; }
public int BulkCopyTimeout { get; set; }
public SqlBulkCopyColumnMappingCollection ColumnMappings { get; }
public string DestinationTableName { get; set; }
public bool EnableStreaming { get; set; }
public int NotifyAfter { get; set; }
public event SqlRowsCopiedEventHandler SqlRowsCopied; public void Close();
public void WriteToServer(DataRow[] rows);
public void WriteToServer(DataTable table);
public void WriteToServer(IDataReader reader);
public void WriteToServer(DataTable table, DataRowState rowState);
}

我们只需关注 WriteToServer 方法。因为我们的数据源不是数据库或excel,所以我们直接不考虑 WriteToServer(IDataReader reader)。WriteToServer(DataRow[] rows) 直接无视,不多解释,所以我们只需考虑用 WriteToServer(DataTable table) 就行了。开干!

一、构造一个结构严谨的 DataTable。 
由于 SqlBulkCopy 要求 DataTable 的列必须和表列顺序一致,并且不能多也不能少,所以,我们首先要创建一个和目标表字段顺序一致的 DataTable,先查出目标表的结构:

static List<SysColumn> GetTableColumns(SqlConnection sourceConn, string tableName)
{
string sql = string.Format("select * from syscolumns inner join sysobjects on syscolumns.id=sysobjects.id where sysobjects.xtype='U' and sysobjects.name='{0}' order by syscolumns.colid asc", tableName); List<SysColumn> columns = new List<SysColumn>();
using (SqlConnection conn = (SqlConnection)((ICloneable)sourceConn).Clone())
{
conn.Open();
using (var reader = conn.ExecuteReader(sql))
{
while (reader.Read())
{
SysColumn column = new SysColumn();
column.Name = reader.GetDbValue("name");
column.ColOrder = reader.GetDbValue("colorder"); columns.Add(column);
}
}
conn.Close();
} return columns;
}

得到基本的表结构 List<SysColumn>,再创建“严格”的 DataTable 对象:

DataTable dt = new DataTable();

Type modelType = typeof(TModel);

List<SysColumn> columns = GetTableColumns(conn, tableName);
List<PropertyInfo> mappingProps = new List<PropertyInfo>(); var props = modelType.GetProperties();
for (int i = ; i < columns.Count; i++)
{
var column = columns[i];
PropertyInfo mappingProp = props.Where(a => a.Name == column.Name).FirstOrDefault();
if (mappingProp == null)
throw new Exception(string.Format("model 类型 '{0}'未定义与表 '{1}' 列名为 '{2}' 映射的属性", modelType.FullName, tableName, column.Name)); mappingProps.Add(mappingProp);
Type dataType = GetUnderlyingType(mappingProp.PropertyType);
if (dataType.IsEnum)
dataType = typeof(int);
dt.Columns.Add(new DataColumn(column.Name, dataType));
}

注意,构造 DataColumn 时,要给 Column 设置 DataType,及数据类型。因为如果不指定数据类型,默认是 string 类型,那样会导致将数据发送至数据库时会引起数据转换,会有些许无谓的性能损耗,同时,如果不指定数据类型,导入一些数据类型时可能会失败,比如模型属性是 Guid 类型,导入时会出现类型转换失败异常。

二、利用反射,获取属性值,构造一行一行的 DataRow,填充 DataTable:

foreach (var model in modelList)
{
DataRow dr = dt.NewRow();
for (int i = ; i < mappingProps.Count; i++)
{
PropertyInfo prop = mappingProps[i];
object value = prop.GetValue(model); if (GetUnderlyingType(prop.PropertyType).IsEnum)
{
if (value != null)
value = (int)value;
} dr[i] = value ?? DBNull.Value;
} dt.Rows.Add(dr);
}

三、一个完整包含数据的 DataTable 对象就创建好了,我们就可以使用 SqlBulkCopy 插入数据了:

public static void BulkCopy<TModel>(this SqlConnection conn, List<TModel> modelList, int batchSize, string destinationTableName = null, int? bulkCopyTimeout = null, SqlTransaction externalTransaction = null)
{
bool shouldCloseConnection = false; if (string.IsNullOrEmpty(destinationTableName))
destinationTableName = typeof(TModel).Name; DataTable dtToWrite = ToSqlBulkCopyDataTable(modelList, conn, destinationTableName); SqlBulkCopy sbc = null; try
{
if (externalTransaction != null)
sbc = new SqlBulkCopy(conn, SqlBulkCopyOptions.Default, externalTransaction);
else
sbc = new SqlBulkCopy(conn); using (sbc)
{
sbc.BatchSize = batchSize;
sbc.DestinationTableName = destinationTableName; if (bulkCopyTimeout != null)
sbc.BulkCopyTimeout = bulkCopyTimeout.Value; if (conn.State != ConnectionState.Open)
{
shouldCloseConnection = true;
conn.Open();
} sbc.WriteToServer(dtToWrite);
}
}
finally
{
if (shouldCloseConnection && conn.State == ConnectionState.Open)
conn.Close();
}
}

完事,一个批量插入的 Helper 方法就这么产生了,最终的完整实现如下:

public static class SqlConnectionExtension
{
/// <summary>
/// 使用 SqlBulkCopy 向 destinationTableName 表插入数据
/// </summary>
/// <typeparam name="TModel">必须拥有与目标表所有字段对应属性</typeparam>
/// <param name="conn"></param>
/// <param name="modelList">要插入的数据</param>
/// <param name="batchSize">SqlBulkCopy.BatchSize</param>
/// <param name="destinationTableName">如果为 null,则使用 TModel 名称作为 destinationTableName</param>
/// <param name="bulkCopyTimeout">SqlBulkCopy.BulkCopyTimeout</param>
/// <param name="externalTransaction">要使用的事务</param>
public static void BulkCopy<TModel>(this SqlConnection conn, List<TModel> modelList, int batchSize, string destinationTableName = null, int? bulkCopyTimeout = null, SqlTransaction externalTransaction = null)
{
bool shouldCloseConnection = false; if (string.IsNullOrEmpty(destinationTableName))
destinationTableName = typeof(TModel).Name; DataTable dtToWrite = ToSqlBulkCopyDataTable(modelList, conn, destinationTableName); SqlBulkCopy sbc = null; try
{
if (externalTransaction != null)
sbc = new SqlBulkCopy(conn, SqlBulkCopyOptions.Default, externalTransaction);
else
sbc = new SqlBulkCopy(conn); using (sbc)
{
sbc.BatchSize = batchSize;
sbc.DestinationTableName = destinationTableName; if (bulkCopyTimeout != null)
sbc.BulkCopyTimeout = bulkCopyTimeout.Value; if (conn.State != ConnectionState.Open)
{
shouldCloseConnection = true;
conn.Open();
} sbc.WriteToServer(dtToWrite);
}
}
finally
{
if (shouldCloseConnection && conn.State == ConnectionState.Open)
conn.Close();
}
} public static DataTable ToSqlBulkCopyDataTable<TModel>(List<TModel> modelList, SqlConnection conn, string tableName)
{
DataTable dt = new DataTable(); Type modelType = typeof(TModel); List<SysColumn> columns = GetTableColumns(conn, tableName);
List<PropertyInfo> mappingProps = new List<PropertyInfo>(); var props = modelType.GetProperties();
for (int i = ; i < columns.Count; i++)
{
var column = columns[i];
PropertyInfo mappingProp = props.Where(a => a.Name == column.Name).FirstOrDefault();
if (mappingProp == null)
throw new Exception(string.Format("model 类型 '{0}'未定义与表 '{1}' 列名为 '{2}' 映射的属性", modelType.FullName, tableName, column.Name)); mappingProps.Add(mappingProp);
Type dataType = GetUnderlyingType(mappingProp.PropertyType);
if (dataType.IsEnum)
dataType = typeof(int);
dt.Columns.Add(new DataColumn(column.Name, dataType));
} foreach (var model in modelList)
{
DataRow dr = dt.NewRow();
for (int i = ; i < mappingProps.Count; i++)
{
PropertyInfo prop = mappingProps[i];
object value = prop.GetValue(model); if (GetUnderlyingType(prop.PropertyType).IsEnum)
{
if (value != null)
value = (int)value;
} dr[i] = value ?? DBNull.Value;
} dt.Rows.Add(dr);
} return dt;
}
static List<SysColumn> GetTableColumns(SqlConnection sourceConn, string tableName)
{
string sql = string.Format("select * from syscolumns inner join sysobjects on syscolumns.id=sysobjects.id where sysobjects.xtype='U' and sysobjects.name='{0}' order by syscolumns.colid asc", tableName); List<SysColumn> columns = new List<SysColumn>();
using (SqlConnection conn = (SqlConnection)((ICloneable)sourceConn).Clone())
{
conn.Open();
using (var reader = conn.ExecuteReader(sql))
{
while (reader.Read())
{
SysColumn column = new SysColumn();
column.Name = reader.GetDbValue("name");
column.ColOrder = reader.GetDbValue("colorder"); columns.Add(column);
}
}
conn.Close();
} return columns;
} static Type GetUnderlyingType(Type type)
{
Type unType = Nullable.GetUnderlyingType(type); ;
if (unType == null)
unType = type; return unType;
} class SysColumn
{
public string Name { get; set; }
public int ColOrder { get; set; }
}
}

完整代码

代码不多,仅仅150行,大家可以直接拷走拿去用。其中用了反射,估计吃瓜群众可能不淡定了~哈哈,如果你真有大数据插入需求,这点反射消耗相对大数据插入简直九牛一毛,微乎其微,放心好了。

转自:https://www.cnblogs.com/so9527/p/6193154.html