C#使用SqlBulkCopy将DataTable写入数据库的表中（表不存在则创建新表,数据存在则更新,不存在则插入）

原文:.net使用SqlBulkCopy导入数据（创建新表）

.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：

/// <summary>
/// 将DataTable写入数据库的表中
/// </summary>
/// <param name="source">数据源DataTable</param>
/// <param name="tableName">数据目标的表名</param>
/// <param name="useTransaction">操作过程是否使用事务</param>
/// <param name="databaseConnString">数据库连接字符串</param>
/// <param name="dropTable">删除DB中已存在的表(并自动新建表)</param>
/// <param name="primaryKeys">主键的列名</param>
public void WriteToDataBase(DataTable source, string tableName, bool useTransaction, string databaseConnString, bool dropTable, string[] primaryKeys)
{
//判断表是否存在
SqlHelper.ConnectionString = 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 = SqlHelper.ExecuteDataset(sql).Tables[0];
if (dt.Rows.Count > 0)
{
if (dropTable == true)
{
sql = "drop table " + tableName + "";   //清除已存在的表
SqlHelper.ExecuteNonQuery(SqlHelper.ConnectionString, CommandType.Text, sql);
}
else
{
SqlBulkCopy sqlbulkcopy = new SqlBulkCopy(databaseConnString, SqlBulkCopyOptions.UseInternalTransaction | SqlBulkCopyOptions.FireTriggers);
sqlbulkcopy.DestinationTableName = tableName;//数据库中的表名

sqlbulkcopy.WriteToServer(source);
return;
}
}
this.CreateTable(source.Columns, tableName, primaryKeys);
var sqlBulkCopy = new System.Data.SqlClient.SqlBulkCopy(databaseConnString, SqlBulkCopyOptions.FireTriggers);//启动触发器
if (useTransaction == true)
{
sqlBulkCopy = new System.Data.SqlClient.SqlBulkCopy(databaseConnString, SqlBulkCopyOptions.UseInternalTransaction | SqlBulkCopyOptions.FireTriggers); //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);
}

/// <summary>
/// 创建表以及触发器
/// </summary>
/// <param name="columns">列名</param>
/// <param name="tableName">表名</param>
/// <param name="primaryKeys">主键的列名</param>
public void CreateTable(System.Data.DataColumnCollection columns, string tableName, string[] primaryKeys)
{
if (primaryKeys == null || primaryKeys.Length < 1)
{
MessageBox.Show("主键不允许为空!");
return;
}
StringBuilder sb = new StringBuilder();
// sb.Append("create table [" + tableName + "] (autoId  int identity(1,1),");
sb.Append("create table [" + tableName + "] (");
foreach (DataColumn column in columns)
{
sb.Append(" [" + column.ColumnName + "] " + this.GetTableColumnType(column.DataType) + ",");
}

string sql = sb.ToString();
sql = sql.TrimEnd(',');
sql += ")";

sb.Clear();
var temp1 = primaryKeys;
for (int i = 0; i < primaryKeys.Length; i++)
{
temp1[i] = tableName + "." + primaryKeys[i] + "=Inserted." + primaryKeys[i];
}
List<string> temp2 = new List<string>();
for (int i = 0; i < columns.Count; i++)
{
temp2.Add(columns[i].ColumnName + "=Inserted." + columns[i].ColumnName);
}
List<string> temp3 = new List<string>();
for (int i = 0; i < columns.Count; i++)
{
temp3.Add(columns[i].ColumnName);
}
sb.Append("CREATE TRIGGER [tri_" + tableName + "_edit]  ON [" + tableName + "] instead of insert as");
sb.Append("  IF EXISTS (");
sb.Append("SELECT * FROM    " + tableName + ",Inserted WHERE " + String.Join(" AND ", temp1) + ")");
sb.Append(" UPDATE [" + tableName + "] SET " + string.Join(",", temp2) + " FROM [" + tableName + "] JOIN inserted ON " + String.Join(" AND ", temp1) + " ");
sb.Append(" ELSE ");

sb.Append(" INSERT  [" + tableName + "](" + string.Join(",", temp3) + ") SELECT  " + string.Join(",", temp3) + " FROM inserted  ");
// sql = sql + " ; " + sb.ToString();
SqlHelper.ExecuteNonQuery(SqlHelper.ConnectionString, CommandType.Text, sql);
SqlHelper.ExecuteNonQuery(SqlHelper.ConnectionString, CommandType.Text, sb.ToString());
}

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;
}