/// <summary>
/// 设置DataTable到数据库中表的映射
/// </summary>
/// <param name="mappings">The mappings.</param>
/// <param name="table">The table.</param>
private void SetMappings(SqlBulkCopyColumnMappingCollection mappings, RdbTable table)
{
foreach (var column in table.Columns)
{
mappings.Add(column.Name, column.Name);
}
//暂留：通过查询的真实列名来实现 Mapping。
//var sql = string.Format("SELECT TOP 0 * FROM [{0}]", _table.Name);
//var dbNames = new List<string>();
//using (var reader = _meta.DBA.QueryDataReader(sql))
//{
// for (int i = 0, c = reader.FieldCount; i < c; i++)
// {
// var name = reader.GetName(i);
// dbNames.Add(name);
// }
//}
//foreach (var column in _table.Columns)
//{
// var correspondingDbName = dbNames.First(c => string.Compare(c, column.Name, true) == 0);
// mappings.Add(column.Name, correspondingDbName);
//}
}
/// <summary>
/// 设置DataTable到数据库中表的映射
/// </summary>
/// <param name="mappings"></param>
private void SetMappings(SqlBulkCopyColumnMappingCollection mappings)
{
var cmd = this._db.CreateCommand();
cmd.CommandText = string.Format("select top 1 * from [{0}]", this._table.Name);
var dbNames = new List<string>();
using (var reader = cmd.ExecuteReader())
{
for (int i = 0, c = reader.FieldCount; i < c; i++)
{
var name = reader.GetName(i);
dbNames.Add(name);
}
}
foreach (var column in this._table.Columns)
{
var correspondingDbName = dbNames.First(c => string.Compare(c, column.Name, true) == 0);
mappings.Add(column.Name, correspondingDbName);
}
}
/// <summary>
/// Maps columns by name. Required by SqlBulkCopy if schema changes or columns are out of order.
/// </summary>
private void MapColumns(SqlBulkCopyColumnMappingCollection columnMappings, IEnumerable<string> tableColumnNames,
DataColumnCollection importFileColumns)
{
var importColumnNames = importFileColumns.Cast<DataColumn>().Select(c => c.ColumnName);
var columnsInCommon = tableColumnNames.Intersect(importColumnNames);
foreach (var column in columnsInCommon)
{
columnMappings.Add(column, column);
}
}
