下拉列表中 SQL 联合之间的文本 - ASP.net c#

Question

我有一个 SQL 查询，它带回最重要的员工，应该出现在下拉列表的顶部，然后是下面的所有其他员工。

查询是使用联合构建的，以将两个查询收集在一起。

我想在下拉列表顶部放置文本，并在联合之间放置文本。这可能吗？

E.G “Preferred Staff Members”作为最高层，“All Other Staff members”将两个工会分开

select DISTINCT e.EMPLOY_REF, e.FORENAME + ' ' + e.SURNAME as Name
from EMPLOYEE_TABLE e

where e.ID = @ID
and e.DATE_LEFT IS NULL or e.DATE_LEFT > GETDATE()

UNION ALL

select DISTINCT e.EMPLOY_REF, e.FORENAME + ' ' + e.SURNAME as Name
from EMPLOYEE_TABLE e
where e.DATE_LEFT IS NULL or e.DATE_LEFT > GETDATE()
ORDER BY Name    

Answer 1

您最好的选择可能是在每个查询中包含某种排序顺序字段。也许是一个标识符，例如标记他们首选的 astrick。

-- Preferred Employees
SELECT '* ' + NameInfo, 1
FROM Employees
WHERE YaddaYadda

UNION

-- Normal Employees
SELECT NameInfo, 2
FROM Employees
WHERE YaddaYadda

然后您可以在代码中使用排序依据，先按排序顺序，然后按名称。

Answer 2

你可以试试关注

SELECT 0, 'Preferred Staff Members' 
UNION ALL
select DISTINCT e.EMPLOY_REF, e.FORENAME + ' ' + e.SURNAME as Name
from EMPLOYEE_TABLE e

where e.ID = @ID
and e.DATE_LEFT IS NULL or e.DATE_LEFT > GETDATE()

UNION ALL

SELECT -1, 'All Other Staff members' 
UNION ALL


select DISTINCT e.EMPLOY_REF, e.FORENAME + ' ' + e.SURNAME as Name
from EMPLOYEE_TABLE e
where e.DATE_LEFT IS NULL or e.DATE_LEFT > GETDATE()
ORDER BY Name

然后您可以轻松识别（0 或 -1）选择了哪个选项

Answer 3

您可以在两者之间添加一个虚拟选择

SELECT 'Name 1' AS A, 1 AS sortOrder
UNION ALL
SELECT '----' AS B, 2 AS sortOrder
UNION ALL
SELECT 'Name 2' AS C, 3 AS sortOrder
ORDER BY sortOrder, A

在你的情况下，这看起来像这样

SELECT DISTINCT e.EMPLOY_REF, e.FORENAME + ' ' + e.SURNAME as Name, 1 AS sortOrderFROM EMPLOYEE_TABLE e
UNION ALL
SELECT '----', '----' AS B, 2 AS sortOrder
UNION ALL
SELECT DISTINCT e.EMPLOY_REF, e.FORENAME + ' ' + e.SURNAME as Name, 3 AS sortOrderFROM EMPLOYEE_TABLE e
ORDER BY sortOrder, Name