如何在SQL Server 2008中使用存儲過程中的if來比較兩個字符串？

Question

我想要做這樣的事情：

declare @temp as varchar 
    set @temp='Measure' 

if(@temp == 'Measure') 
    Select Measure from Measuretable 
else 
    Select OtherMeasure from Measuretable 

Answer 1

兩件事情：

1. 只需要一（1）等號評估
2. 您需要指定的長度在VARCHAR上 - 默認是單個字符。

---

使用：

DECLARE @temp VARCHAR(10) 
    SET @temp = 'm' 

IF @temp = 'm' 
    SELECT 'yes' 
ELSE 
    SELECT 'no' 

VARCHAR(10)意味着VARCHAR可容納多達10個字符。行爲的更多例子 -

DECLARE @temp VARCHAR 
    SET @temp = 'm' 

IF @temp = 'm' 
    SELECT 'yes' 
ELSE 
    SELECT 'no' 

...將返回 「是」

DECLARE @temp VARCHAR 
    SET @temp = 'mtest' 

IF @temp = 'm' 
    SELECT 'yes' 
ELSE 
    SELECT 'no' 

...將返回 「不」。

Answer 2

declare @temp as varchar 
    set @temp='Measure' 
    if(@temp = 'Measure') 
Select Measure from Measuretable 
else 
Select OtherMeasure from Measuretable 

Answer 3

你想要的是一個SQL case語句。 這些形式可以是：

select case [expression or column] 
    when [value] then [result] 
    when [value2] then [result2] 
    else [value3] end 

或：

select case 
    when [expression or column] = [value] then [result] 
    when [expression or column] = [value2] then [result2] 
    else [value3] end 

在你的榜樣，你是後：

declare @temp as varchar(100) 
set @temp='Measure' 

select case @temp 
    when 'Measure' then Measure 
    else OtherMeasure end 
from Measuretable 

Answer 4

你也可以嘗試一下本作匹配的字符串。

DECLARE @temp1 VARCHAR(1000) 
    SET @temp1 = '<li>Error in connecting server.</li>' 
DECLARE @temp2 VARCHAR(1000) 
    SET @temp2 = '<li>Error in connecting server. connection timeout.</li>' 

IF @temp1 like '%Error in connecting server.%' OR @temp1 like '%Error in connecting server. connection timeout.%' 
    SELECT 'yes' 
ELSE 
    SELECT 'no'