Question

我想做这样的事情：

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

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

Answer 1

两件事：

只需要一（1）个等号来评估
您需要在VARCHAR上指定长度 - 默认为单个字符。

使用：

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

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

VARCHAR(10)表示VARCHAR最多可容纳10个字符。行为的更多例子 -

DECLARE @temp VARCHAR
    SET @temp = 'm'

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

...将返回“是”

DECLARE @temp VARCHAR
    SET @temp = 'mtest'

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

...将返回“否”。

Answer 2

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

Answer 3

您想要的是SQL案例陈述。这些形式是：

  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

在你的例子中，你是：

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

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

Answer 4

您也可以尝试使用匹配字符串。

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'

如何在sql server 2008中的存储过程中使用if比较两个字符串？

4 个答案: