Question

我需要使用sql将状态名称列为核对表。即如果用户第一次登陆该页面，他应该看到所有状态，当他进入编辑模式时，他应该看到所有状态和所选状态必须被检查。如何使用单个存储过程实现此目的。我试过这个

create proc spGetList
AS
Begin
    SELECT DISTINCT A.* 
    FROM State A 
    LEFT JOIN UserPreferedState B ON A.StateId = B.StateId 
    WHERE UserId = 3
End

但问题是我不知道如何在存储过程中添加新列（比如说IsSelected）并将值设置为1如果选择了该状态并将值设置为0则该状态未被选中

示例：

表：UserPreferedState

Id  UserId  StateId
-------------------
 1    1        1
 2    1        2
 3    2        1
 4    2        2
 5    3        1

表：State

Id  StateName
--------------
1   ABC
2   DEF
3   GHI

我想要userid = 3时的结果：

Id  StateName  IsSelected 
--------------------------
1   ABC           1
2   DEF           0
3   GHI           0

我想要userid = 1时的结果：

Id  StateName  IsSelected
-------------------------
1   ABC           1
2   DEF           1
3   GHI           0

Answer 1

享受。这也是小提琴：http://sqlfiddle.com/#!3/217ce/2

CREATE TABLE state (
StateId INT,
StateName VARCHAR(100)  
);

CREATE TABLE userPreferredState (
Id INT,
UserId INT,
StateId INT
); 

INSERT INTO state (StateId, StateName)
VALUES (1, 'ABC'), (2, 'DEF'), (3, 'GHI');

INSERT INTO userPreferredState (Id, UserId, StateId) 
VALUES (1, 1, 1), (2, 1, 2), (3, 2, 1), (4, 2, 2), (5, 3, 1);

CREATE PROCEDURE getStateListForUser @User int
AS
SELECT 
s.StateId AS Id,
s.stateName,
CASE WHEN (ups.UserId = @User) THEN '1' ELSE '0' END AS IsSelected
FROM
State s
LEFT JOIN
UserPreferredState ups ON s.StateId = ups.StateId AND ups.UserId = @User
GO

要运行它，请致电：

EXEC getStateListForUser @User = 1
EXEC getStateListForUser @User = 3

无法使用单个存储过程列出所有项目和所选项目

1 个答案: