Question

这是我检索数据的方式

select myPlan from myTable

这是结果，

        myPlan
=====================
True  , False , True
False , True  , False
False , True  , True

在每一行中，我有三个以逗号分隔的布尔值第一个布尔值代表早餐，第二个是午餐，最后一个是晚餐。

我只想将结果替换为

        myPlan
=====================
BreakFast , Dinner
Lunch
Lunch , Dinner

我可以仅使用sql query进行此替换吗？我正在使用SQL server 2008 R2！

Answer 1

由于你只有3个布尔值，你可以使用case语句来获得所有8种可能性。

SELECT
    (CASE
    WHEN myPlan = 'True , True , True'
    THEN 'Breakfast, Lunch, Dinner'
    WHEN myPlan = 'True , True , False'
    THEN 'Breakfast, Lunch'
    WHEN myPlan = 'True , False , False'
    THEN 'Breakfast'
    WHEN myPlan = 'True , False , True'
    THEN 'Breakfast, Dinner'
    WHEN myPlan = 'False , False , True'
    THEN 'Dinner'
    WHEN myPlan = 'False , True , True'
    THEN 'Lunch, Dinner'
    WHEN myPlan = 'False , True , False'
    THEN 'Lunch'
    ELSE ''
    END) myPlan
FROM myTable

Answer 2

您可以按如下方式使用字符串函数。

DECLARE @TEMP AS TABLE(MyPlan VARCHAR(100))

INSERT INTO @TEMP(MyPlan) VALUES ('True  , False , True')
INSERT INTO @TEMP(MyPlan) VALUES ('False , True  , False')
INSERT INTO @TEMP(MyPlan) VALUES ('False , True  , True')

SELECT

     CASE 
        WHEN RTRIM(SUBSTRING(MyPlan,1,5)) = 'TRUE' THEN 'BREAKFAST'
        ELSE '' 
    END 
    +CASE 
        WHEN RTRIM(SUBSTRING(MyPlan,9,5)) = 'TRUE' THEN ',LUNCH'
        ELSE '' 
    END 
    +CASE 
        WHEN RTRIM(SUBSTRING(MyPlan,17,5)) = 'TRUE' THEN ',DINNER'
        ELSE '' 
    END 

FROM @TEMP

Answer 3

更短的解决方案：

select 
decode(substr(myPlan,0,1),'T','Breakfast',null) ||  decode(substr(myPlan,0,1),'T',' , ',null) ||
decode(substr(myPlan,9,1),'T','Lunch',null) ||  decode(substr(myPlan,9,1),'T',' , ',null) ||
decode(substr(myPlan,17,1),'T','Dinner',null) 
from mytable;

在sql查询中替换字符串

3 个答案: