/// <summary>
/// 执行查询并将第一个结果集包装成 DataTable 返回
/// </summary>
/// <param name="query">要执行的查询对象</param>
/// <returns>查询结果</returns>
public static DataTable ExecuteDataTable(this IDbExecutable query)
{
using (var context = query.Execute())
{
return(context.LoadDataTable(0, 0));
}
}
/// <summary>
/// 执行没有结果的查询
/// </summary>
/// <param name="query">要执行的查询对象</param>
/// <returns>查询所影响的行数</returns>
public static int ExecuteNonQuery(this IDbExecutable query)
{
using (var context = query.Execute())
{
return(context.RecordsAffected);
}
}
/// <summary>
/// 执行查询并将所有结果集包装成 DataTable 返回
/// </summary>
/// <param name="query">要执行的查询对象</param>
/// <returns>查询结果</returns>
public static DataTable[] ExecuteAllDataTables(this IDbExecutable query)
{
List <DataTable> dataTables = new List <DataTable>();
using (var context = query.Execute())
{
do
{
dataTables.Add(context.LoadDataTable(0, 0));
} while (context.NextResult());
}
return(dataTables.ToArray());
}
/// <summary>
/// 执行查询并返回首行首列
/// </summary>
/// <param name="query">要执行的查询对象</param>
/// <returns>查询结果</returns>
public static object ExecuteScalar(this IDbExecutable query)
{
using (var context = query.Execute())
{
var record = context.ReadRecord();
if (record != null && record.FieldCount > 0)
{
return(record[0]);
}
else
{
return(null);
}
}
}
/// <summary>
/// 执行查询并返回首行
/// </summary>
/// <param name="query">要执行的查询对象</param>
/// <returns>查询结果</returns>
public static DataRow ExecuteFirstRow(this IDbExecutable query)
{
//UNDONE
using (var context = query.Execute())
{
var data = context.LoadDataTable(0, 1);
if (data.Rows.Count > 0)
{
return(data.Rows[0]);
}
else
{
return(null);
}
}
}