/// <summary>
/// 获取最小值
/// </summary>
/// <typeparam name="T">实体类型</typeparam>
/// <param name="queryable">查询对象</param>
/// <param name="expression">查询字段 (例如：it=>it.fieldName)</param>
/// <returns>object</returns>
public static object Min <T>(this Queryable <T> queryable, Expression <Func <T, object> > expression)
{
ResolveExpress re = new ResolveExpress();
var minField = re.GetExpressionRightField(expression, queryable.DB);
return(Min <T, object>(queryable, minField));
}
/// <summary>
/// 条件筛选 ( 例如：expression 为 it=>it.id, inValues值为 new string[]{"1" ,"2"} 生成的SQL就是 id in('1','2') )
/// </summary>
/// <typeparam name="T">表实体类型</typeparam>
/// <typeparam name="FieldType">In的字段类型</typeparam>
/// <param name="queryable">查询对象</param>
/// <param name="expression">In的字段（例如：it=>it.id）</param>
/// <param name="inValues">In的值的集合</param>
/// <returns>Queryable</returns>
public static Queryable <T> In <T, FieldType>(this Queryable <T> queryable, Expression <Func <T, object> > expression, List <FieldType> inValues)
{
ResolveExpress re = new ResolveExpress();
var InFieldName = re.GetExpressionRightField(expression, queryable.DB);
return(In <T, FieldType>(queryable, InFieldName, inValues));
}
/// <summary>
/// 分组
/// </summary>
/// <typeparam name="T">表实体类型</typeparam>
/// <param name="queryable">查询对象</param>
/// <param name="expression">分组字段 (例如：it=>it.fieldName)</param>
/// <returns>Queryable</returns>
public static Queryable <T> GroupBy <T>(this Queryable <T> queryable, Expression <Func <T, object> > expression)
{
ResolveExpress re = new ResolveExpress();
var field = re.GetExpressionRightField(expression, queryable.DB);
var pre = queryable.GroupByValue.IsValuable() ? "," : "";
queryable.GroupByValue += pre + field;
return(queryable);
}
/// <summary>
/// 排序
/// </summary>
/// <typeparam name="T">表实体类型</typeparam>
/// <param name="queryable">查询对象</param>
/// <param name="expression">排序字段 it=>it.fieldName </param>
/// <param name="type">排序类型</param>
/// <returns>Queryable</returns>
public static Queryable <T> OrderBy <T>(this Queryable <T> queryable, Expression <Func <T, object> > expression, OrderByType type = OrderByType.asc)
{
ResolveExpress re = new ResolveExpress();
var field = re.GetExpressionRightField(expression, queryable.DB);
if (queryable.JoinTableValue.IsValuable())
{
field = re.GetExpressionRightFieldByNT(expression, queryable.DB);
}
var pre = queryable.OrderByValue.IsValuable() ? "," : "";
queryable.OrderByValue += pre + field + " " + type.ToString().ToUpper();
return(queryable);
}
