.net使用SqlBulkCopy导入数据

 .net2.0后ado.net提供了一个快速导入sqlserver的方法sqlbulkcopy.导入效率非常高. 

包装了一个简单的sqlbulkcopy类，用于数据从datatable导入到sqlserver.代码如下： 

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

namespace taihe.framework.tools.import
{
public class SqlBulkCopy
{
private int timeout = 1800;
private System.Data.SqlClient.SqlBulkCopy sqlBulkCopy = null;

public SqlBulkCopy()
{
}

public SqlBulkCopy(int timeout)
{
this.timeout = timeout;
}

public void WriteToDataBase(DataTable source, string tableName,bool useTransaction,string dataBaseConnString,bool clearTable)
{
//判断表是否存在
taihe.framework.data.datalayer.SqlDataHelper dataHelper = new data.datalayer.SqlDataHelper(dataBaseConnString);
dataHelper.IsConnString = true; //使用数据库连接字符串创建sqlserver操作对象
string sql = "select * from sys.objects where type='U' and name='" + tableName + "'";
DataTable dt = dataHelper.ExecuteDataSet(sql).Tables[0];
if (dt.Rows.Count > 0)
{
if (clearTable == true)
{
sql = "drop table " + tableName + ""; //清除已存在的表
}
else
{
throw new Exception("要创建的表已存在");
}
}
this.CreateTable(dataHelper, source.Columns, tableName);
sqlBulkCopy = new System.Data.SqlClient.SqlBulkCopy(dataBaseConnString);
if (useTransaction == true)
{
sqlBulkCopy = new System.Data.SqlClient.SqlBulkCopy(dataBaseConnString, SqlBulkCopyOptions.UseInternalTransaction); //导入的数据在一个事务中
}
sqlBulkCopy.DestinationTableName = tableName;
foreach (DataColumn c in source.Columns)
{
sqlBulkCopy.ColumnMappings.Add(c.ColumnName, c.ColumnName);
}
sqlBulkCopy.BulkCopyTimeout = this.timeout; //超时时间
sqlBulkCopy.BatchSize = 3000; //每次传输3000行
sqlBulkCopy.WriteToServer(source);
}

public void CreateTable(taihe.framework.data.datalayer.SqlDataHelper dataHelper, System.Data.DataColumnCollection columns,string tableName)
{
StringBuilder sb = new StringBuilder();
sb.Append("create table [" + tableName + "] (autoId int identity(1,1),");
foreach (DataColumn column in columns)
{
sb.Append(" [" + column.ColumnName + "] " + this.GetTableColumnType(column.DataType) + ",");
}
string sql = sb.ToString();
sql = sql.TrimEnd(',');
sql += ")";
dataHelper.ExecuteNonQuery(sql);
}

private string GetTableColumnType(System.Type type)
{
string result = "varchar(255)";
string sDbType = type.ToString();
switch (sDbType)
{
case "System.String":
break;
case "System.Int16":
result = "int";
break;
case "System.Int32":
result = "int";
break;
case "System.Int64":
result = "float";
break;
case "System.Decimal":
result="decimal(18,4)";
break;
case "System.Double":
result = "decimal(18,4)";
break;
case "System.DateTime":
result = "datetime";
break;
default:
break;
}
return result;
}
}
}