如何使这条IF语句跳到另一条if语句？

Question

如何使这个If语句跳到下面的if语句？然后，我尝试了其他if，但它不起作用。我希望无论是否将输入传递给变量，它都会显示出来。

declare @sql varchar(8000)
declare @sql_where varchar(8000)

declare @ww varchar(10)
declare @plant varchar(10)
declare @plnr_id varchar(10)

set @plant = 'CS58'
set @ww = '201240'  
set @plnr_id = 'G37'

set @sql_where = 'where'
set @sql = 'select * from  rout_sub_doi '

if len(@plant) > 0 
    set @sql_where = @sql_where + ' plant = ''' + @plant + ''' '

if len(@ww) > 0
    set @sql_where = @sql_where + 'AND sys_intel_ww = ''' + @ww + ''' '

if len(@plnr_id) > 0 

    set @sql_where = @sql_where + ' AND plnr_id = ''' + @plnr_id + ''' '


print @sql
print @sql_where

exec (@sql + @sql_where )

Answer 1

处理未知数量的条件的常见方法是，在已知id不可为空的情况下，将第一个条件设为WHERE 1=1或WHERE id IS NOT NULL等良性条件。

declare @sql varchar(8000)
declare @sql_where varchar(8000)

declare @ww varchar(10)
declare @plant varchar(10)
declare @plnr_id varchar(10)

set @plant = 'CS58'
set @ww = '201240'  
set @plnr_id = 'G37'

set @sql_where = ''
set @sql = 'select * from rout_sub_doi where 1=1 '

if len(@plant) > 0 
    set @sql_where = @sql_where + 'AND plant = ''' + @plant + ''' '

if len(@ww) > 0
    set @sql_where = @sql_where + 'AND sys_intel_ww = ''' + @ww + ''' '

if len(@plnr_id) > 0 
    set @sql_where = @sql_where + 'AND plnr_id = ''' + @plnr_id + ''' '

print @sql
print @sql_where

exec (@sql + @sql_where )