/// <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 IDbExecutableQuery query)
{
//UNDONE
var data = query.ExecuteDataTable();
if (data.Rows.Count > 0)
{
return(data.Rows[0]);
}
else
{
return(null);
}
}
/// <summary>
/// 查询数据库并将第一个结果集填充实体类型
/// </summary>
/// <typeparam name="T">实体类型</typeparam>
/// <param name="query">要执行的查询</param>
/// <param name="converter">实体转换器</param>
/// <returns>实体集</returns>
public static T[] ExecuteEntities <T>(this IDbExecutableQuery query, Func <DataRow, T> converter)
{
var data = query.ExecuteDataTable();
return(data.GetRows().Select(dataItem => converter(dataItem)).ToArray());
}
/// <summary>
/// 查询数据库并将第一个结果集填充实体类型
/// </summary>
/// <typeparam name="T">实体类型</typeparam>
/// <param name="query">要执行的查询</param>
/// <param name="converter">实体转换器</param>
/// <returns>实体集</returns>
public static T[] ExecuteEntities <T>(this IDbExecutableQuery query, IEntityConverter <T> converter) where T : new()
{
var data = query.ExecuteDataTable();
return(data.GetRows().Select(dataItem => dataItem.ToEntity(converter)).ToArray());
}
/// <summary>
/// 执行查询并将第一个结果集填充动态对象列表
/// </summary>
/// <param name="query">要执行的查询</param>
/// <returns>查询结果</returns>
public static dynamic[] ExecuteDynamics(this IDbExecutableQuery query)
{
var data = query.ExecuteDataTable();
return(ToDynamics(data));
}
/// <summary>
/// 执行查询并将第一行数据数据转换为 DataRowView 返回
/// </summary>
/// <param name="query">要执行的查询</param>
/// <returns>转换为 DataRowView 的数据集合</returns>
public static DataRowView ExecuteFirstDataRowView(this IDbExecutableQuery query)
{
return(query.ExecuteDataTable().GetRowViews().FirstOrDefault());
}
/// <summary>
/// 执行查询并将数据转换为 DataRowView 集合返回
/// </summary>
/// <param name="query">要执行的查询</param>
/// <returns>转换为 DataRowView 的数据集合</returns>
public static IEnumerable <DataRowView> ExecuteDataRowViews(this IDbExecutableQuery query)
{
return(query.ExecuteDataTable().GetRowViews());
}
/// <summary>
/// 执行查询并返回第一列数据
/// </summary>
/// <typeparam name="T">列类型</typeparam>
/// <param name="query">要执行的查询</param>
/// <returns>第一列的数据</returns>
public static T[] ExecuteFirstColumn <T>(this IDbExecutableQuery query)
{
return(query.ExecuteDataTable().Column <T>());
}