[英]Translate an postgresql query to entityframework core in asp.net core
I am trying to translate the following Postgresql query in a dotnet api application using entityframework core in a way to return a list of objects containing the results in the output of that query.我正在尝试使用 entityframework 核心在 dotnet api 应用程序中翻译以下 Postgresql 查询,以返回包含该查询 output 中结果的对象列表。
sql query to translate: sql 查询翻译:
select speciality_type, speciality_priority ,
count(speciality_type)
from specialties
group by speciality_priority, speciality_type
desired output:所需的 output:
knowing that the last column is the count column witch is not initially in the table and that I created in the query.知道最后一列是计数列,女巫最初不在表中,而是我在查询中创建的。 I want to get all these columns from
_DataAccessObject.SpecialitiesTable
and create from its values another list of an object that I create object(string type, int priority, int count)
我想从
_DataAccessObject.SpecialitiesTable
中获取所有这些列,并从它的值创建另一个我创建object(string type, int priority, int count)
I tried a lot of stuff like _DataAccess.SpecialitiesTable.GroupBy(...).Select(...)
most of them give me a error once function is called saying that the EF core statement could not be translated to sql.我尝试了很多类似
_DataAccess.SpecialitiesTable.GroupBy(...).Select(...)
的东西,一旦调用 function 说 EF 核心语句无法转换为 sql,它们中的大多数都会给我一个错误。
Thank you in advance.先感谢您。
Try the following query:尝试以下查询:
var result = await _DataAccess.SpecialitiesTable
.GroupBy(s => new { s.speciality_type, s.speciality_priority })
.Select(g => new
{
g.Key.speciality_type,
g.Key.speciality_priority,
count = g.Count()
})
.ToListAsync();
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