Solved

Case selection with from clause

Posted on 2008-10-08
8
750 Views
Last Modified: 2012-05-05
Experts i am trying to replace a dynamic sql query inside my sproc with a general statement but using CASE. I am trying to replace if then else and appending to a string with using CASE stmts...I believe that will improve the performance of the query. Is that correct ? I wrote something but incorrect, can u please guide me to correct it ? I hope you understand what i am trying to achieve here.

declare @size integer
set @size=1
select * from size + (case @size<>0 then ',size_scale where size.size_scale_id=size_scale.size_scale_id and size.size_scale_id=@size' end)
0
Comment
Question by:dotnetpro
8 Comments
 
LVL 92

Expert Comment

by:Patrick Matthews
ID: 22671977
declare @size integer, @sql varchar(max)
set @size=1
set @sql = 'select * from size ' + (case @size<>0 then ',size_scale where size.size_scale_id=size_scale.size_scale_id and size.size_scale_id=' + CAST(@size AS varchar) end)
exec(@sql)
0
 
LVL 5

Expert Comment

by:Cvijo123
ID: 22672003
ithis should do i think
if u wanna to return all records just set @size = null

declare @size int

set @size=1


select
    *
from size
left join size_scale
    on size.size_scale_id = size_scale.size_scale_id
where
 (@size is null or size.size_scale_id = @size )


0
 
LVL 39

Expert Comment

by:BrandonGalderisi
ID: 22672015
Can you include the rest of your SQL.  I'm guessing you are trying to do something like this...
declare @size integer 

set @size=1
 

declare @sql nvarchar(max),@parmList nvarchar(max)

set @sql = 'select field1,field2,field3 '
 
 

if @size <>0 
 

  set @SQL = @SQL + ',size_scale from MyTable where size.size_scale_id=size_scale.size_scale_id and size.size_scale_id=@size' end

else

set @SQL = @SQL + ' from MyTable ' end
 

set @parmList = '@size int'

exec sp_executesql @SQL,@parmlist,@size=@size

Open in new window

0
Windows Server 2016: All you need to know

Learn about Hyper-V features that increase functionality and usability of Microsoft Windows Server 2016. Also, throughout this eBook, you’ll find some basic PowerShell examples that will help you leverage the scripts in your environments!

 
LVL 1

Author Comment

by:dotnetpro
ID: 22672194
Well i am trying to lessen the amount of time taken to execute a set of 4 procedures. There are many parameters that get appended into the query based on their value. I am trying to write one select query that will take care of all the "if then else " scenarios and the query will be cached as well.
I am using sp_executesql as well but that also does not show much effect when the values of the input parameters are changing every time i execute the sql.
0
 
LVL 1

Author Comment

by:dotnetpro
ID: 22672285
Here is the code
@PO_Number varchar(256),              

@PO_Type varchar(256),              

@Vendor varchar(256),              

@Label varchar(256),              

@Gender varchar(256),              

@Season varchar(256),              

@Category varchar(256),              

@Classification varchar(256),              

@Description varchar(256),              

@Style varchar(256),              

@Quality varchar(256),              

@Color varchar(256),              

@Size varchar(256),              

@Type varchar(256),              

@Units_Greater_Than integer,              

@Excess_Inventory varchar(1),              

@Cost_Per_Unit_Over  money,              

@Cost_Per_Unit_Under money,              

@Warehouse varchar(256),              

@Section varchar(256),              

@Units_Less_Than integer,              

@Status varchar(256),              

@SO_Number varchar(256)        

         

AS              

        

        

declare @reporting_job_id bigint        

declare @stmt nvarchar(4000)              

declare @stmt1 nvarchar(4000)              

declare @fields varchar(2000)              

        

        

            

if (@Size <> '_SKIP_')              

begin              

select              

  distinct '(['+size.description+'_units'+'] > 0) and ' as field,              

  space(1) as RecList              

 into              

  #workingtable              

 from size, iter_intlist_to_table(@Size) i_size where              

 --quantity_size.size_id = size.size_id and              

 size.size_id = i_size.number               

              

 set @fields = ''              

 select              

  @fields=@fields+field              

 from              

  #workingtable              

                  

end              

                

set @stmt = ''              

set @stmt1 = ''              

    

--set @stmt='select distinct ''Section: ''+LTRIM(STR(section_number))+''   ''+section_header+'' Inventory'''              

set @stmt='select distinct ''Section: ''+LTRIM(STR(section_number))+''   ''+section_header+'' Inventory'''              

set @stmt= @stmt+' as "MainHeading" '              

set @stmt= @stmt+'from '              

set @stmt= @stmt+'wms_reports_staging_table  '              

if (@Size <> '_SKIP_')              

begin              

 set @stmt= @stmt+', size '              

 set @stmt= @stmt+',iter_intlist_to_table('''+@Size+''') i_size '              

end              

if @Label <> '_SKIP_'              

    set @stmt1 = @stmt1 + ',iter_intlist_to_table('''+@Label+''') i_label '              

if @Classification <> '_SKIP_'              

    set @stmt1 = @stmt1 + ',iter_intlist_to_table('''+@Classification+''') i_class '              

if @Vendor <> '_SKIP_'                  

     set @stmt1 = @stmt1 + ',iter_intlist_to_table('''+@Vendor+''') i_vendor '              

if @Season  <> '_SKIP_'              

    set @stmt1 = @stmt1 + ',iter_intlist_to_table('''+@Season+''') i_season '              

if @Gender <> '_SKIP_'                  

     set @stmt1 = @stmt1 + ',iter_intlist_to_table('''+@Gender+''') i_gender '              

if @Category  <> '_SKIP_'                   

    set @stmt1 = @stmt1 + ',iter_intlist_to_table('''+@Category+''') i_category '              

if @Status  <> '_SKIP_'                   

    set @stmt1 = @stmt1 + ',iter_intlist_to_table('''+@Status+''') i_status '              

if @Description  <> '_SKIP_'                  

    set @stmt1 = @stmt1 + ',iter_intlist_to_table('''+@Description+''') i_carton'              

if @Quality  <> '_SKIP_'                  

    set @stmt1 = @stmt1 + ',iter_intlist_to_table('''+@Quality+''') i_quality '              

if @Color  <> '_SKIP_'                  

    set @stmt1 = @stmt1 + ',iter_intlist_to_table('''+@Color+''') i_color'              

if @Warehouse  <> '_SKIP_'                  

    set @stmt1 = @stmt1 + ',iter_intlist_to_table('''+@Warehouse+''') i_warehouse '              

if @Style  <> '_SKIP_'                  

    set @stmt1 = @stmt1 + ', iter_intlist_to_table('''+@Style+''') i_style '              

if @PO_Type <> '_SKIP_'                  

    set @stmt1 = @stmt1 + ', iter_intlist_to_table('''+@PO_Type+''') i_po_type '              

if @PO_Number <> '_SKIP_'              

    set @stmt1 = @stmt1 + ',iter_charlist_to_table('''+@PO_Number+''') i_po_number '              

if @SO_Number <> '_SKIP_'              

    set @stmt1 = @stmt1 + ',iter_charlist_to_table('''+@SO_Number+''') i_so_number '              

if @Section <> '_SKIP_'                  

    set @stmt1 = @stmt1 + ', iter_intlist_to_table('''+@Section+''') i_section '              

if @Type <> '_SKIP_'                  

    set @stmt1 = @stmt1 + ', iter_charlist_to_table('''+@Type+''') i_type '              

                  

              

--set @stmt1 = @stmt1 + ' where inventory_status = ''Active'' '              

set @stmt1 = @stmt1 + ' where '              

if (@Size <> '_SKIP_')              

begin              

 set @stmt1 = @stmt1 + @fields              

 set @stmt1 = @stmt1 + ' size.size_scale_id = wms_reports_staging_table.size_scale_id and size.size_id = i_size.number and '              

end              

set @stmt1 = @stmt1 + ' 1 = 1 '              

if @Status <> '_SKIP_'              

 set @stmt1 = @stmt1 + ' and (inventory_status_id = i_status.number) '              

if @PO_Number <> '_SKIP_'              

 set @stmt1 = @stmt1 + ' and (po_number = i_po_number.item) '              

if @SO_Number <> '_SKIP_'              

 set @stmt1 = @stmt1 + ' and (so_number = i_so_number.item) '              

if @PO_Type <> '_SKIP_'              

 set @stmt1 = @stmt1 + ' and (po_type_id = i_po_type.number) '              

if @Section <> '_SKIP_'              

 set @stmt1 = @stmt1 + ' and (section_number = i_section.number) '              

if @Type <> '_SKIP_'              

 set @stmt1 = @stmt1 + ' and (case when type='''' then ''nej'' when type is null then ''nej'' else type end = i_type.item) '              

              

if @Vendor <> '_SKIP_'              

 set @stmt1 = @stmt1 + ' and (vendor_id = i_vendor.number) '              

if @Label <> '_SKIP_'              

 set @stmt1 = @stmt1 + 'and (label_id = i_label.number) '              

if @Gender <> '_SKIP_'              

 set @stmt1 = @stmt1 + 'and (gender_id = i_gender.number) '              

if @Season  <> '_SKIP_'              

 set @stmt1 = @stmt1 + 'and (season_id = i_season.number) '              

if @Classification  <> '_SKIP_'              

 set @stmt1 = @stmt1 + 'and (classification_id = i_class.number) '              

if @Category  <> '_SKIP_'              

 set @stmt1 = @stmt1 + 'and (category_id = i_category.number)  '              

if @Description  <> '_SKIP_'              

 set @stmt1 = @stmt1 + 'and (label_description_id = i_carton.number) '              

if @Style  <> '_SKIP_'              

 set @stmt1 = @stmt1 + 'and (style_id = i_style.number) '              

if @Quality  <> '_SKIP_'              

 set @stmt1 = @stmt1 + 'and (quality_id = i_quality.number) '              

if @Color  <> '_SKIP_'              

 set @stmt1 = @stmt1 + 'and (color_id = i_color.number) '              

if @Warehouse  <> '_SKIP_'              

set @stmt1 = @stmt1 + 'and (warehouse_id = i_warehouse.number) '              

--if (@Units_Greater_Than <> 0 )              

--    set @stmt1 = @stmt1 + 'and units > '+ str(@Units_Greater_Than)           

--if (@Units_Less_Than <> 0 )              

--    set @stmt1 = @stmt1 + 'and units < '+ str(@Units_Less_Than)              

if (@Cost_Per_Unit_Over <> 0.0 )              

    set @stmt1 = @stmt1 + 'and cost > '+ str(@Cost_Per_Unit_Over)               

if (@Cost_Per_Unit_Under <> 0.0 )              

    set @stmt1 = @stmt1 + 'and cost < '+ str(@Cost_Per_Unit_Under)              

if (@Excess_Inventory = '1')               

    set @stmt1 = @stmt1 + 'and cost = 0'              

set @stmt1= @stmt1+'  GROUP BY '              

set @stmt1= @stmt1+'  section_number, section_header, '              

set @stmt1= @stmt1+' quality_description+char(1)+label_description+char(1)+gender_description+char(1)+season_description+char(1)+classification_description+char(1)+label_description_description+char(1)+category_description '              

set @stmt1= @stmt1+' ,isnull(type, ''''), cost'              

              

set @stmt1= @stmt1+' having (sum(units) > '+str(@Units_Greater_Than)+' or '+str(@Units_Greater_Than)+' = 0)'              

set @stmt1= @stmt1+' and (sum(units) < '+str(@Units_Less_Than)+' or '+str(@Units_Less_Than)+' = 0)'              

              

set @stmt1= @stmt1+' order by ''Section: ''+LTRIM(STR(section_number))+''   ''+section_header+'' Inventory'''     

             

set @stmt=@stmt+@stmt1       

    
 

execute sp_executesql @stmt       

        

        

              

            

          

        

Open in new window

0
 
LVL 1

Accepted Solution

by:
dotnetpro earned 0 total points
ID: 22741337
Is there anyone following up on this question ?
0
 
LVL 39

Expert Comment

by:BrandonGalderisi
ID: 22743002
Sorry.  Somehow I must have missed you posting the SQL.  I will review this ASAP.
0

Featured Post

PRTG Network Monitor: Intuitive Network Monitoring

Network Monitoring is essential to ensure that computer systems and network devices are running. Use PRTG to monitor LANs, servers, websites, applications and devices, bandwidth, virtual environments, remote systems, IoT, and many more. PRTG is easy to set up & use.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Load balancing is the method of dividing the total amount of work performed by one computer between two or more computers. Its aim is to get more work done in the same amount of time, ensuring that all the users get served faster.
This article shows gives you an overview on SQL Server 2016 row level security. You will also get to know the usages of row-level-security and how it works
Using examples as well as descriptions, and references to Books Online, show the documentation available for datatypes, explain the available data types and show how data can be passed into and out of variables.
Viewers will learn how to use the INSERT statement to insert data into their tables. It will also introduce the NULL statement, to show them what happens when no value is giving for any given column.

861 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

25 Experts available now in Live!

Get 1:1 Help Now