sql server case

use mytest
go

exec p_city 2,4

exec p_city_cnt 2,3

select stuff((select ',' + city_id from cities for xml path('')),1,1,'') concatStr
select stuff((select ',' + city_name from cities for xml path('')),1,1,'') concatStr

　　

USE mytest
GO

IF EXISTS ( select * from dbo.sysobjects where id=OBJECT_ID('dbo.p_city') and type = 'P')
drop procedure p_city
GO

create procedure p_city
	@idx int,
	@idy int
	--,@cnt int output --solution 2.3
AS
BEGIN

	declare @sql nvarchar(2000)
	declare @param nvarchar(2000)

	/*
	--print 'solution - 1.1 - common situation'
	set @sql = N'select city_name from cities where city_id>=@id_start and city_id<=@id_end'
	set @param = N'@id_start int, @id_end int'
	EXEC sp_executesql @sql, @param, @id_start=@idx, @id_end=@idy
	*/

	--print 'solution - 1.2 - for some special situation'
	create table #tmp (city_name varchar(100))
	set @sql = N'insert into #tmp(city_name) select city_name from cities where city_id between @id_start and @id_end'
	set @param = N'@id_start int, @id_end int'
	EXEC sp_executesql @sql, @param, @id_start=@idx, @id_end=@idy
	select * from #tmp
	--set @cnt = (select count(1) from #tmp) --solution 2.3
	IF EXISTS (select name from tempdb..sysobjects where id=OBJECT_ID('tempdb..#tmp') and type='U')
		drop table #tmp

	/*
	-- not ok
	print 'solution - 1.3 - use table variable'
	exec( N'declare @ctname table(city_name varchar(100))')
	set @sql = N'insert into @ctname(city_name) select city_name from cities where city_id between @id_start and @id_end'
	set @param = N'@id_start int, @id_end int'
	EXEC sp_executesql @sql, @param, @id_start=@idx, @id_end=@idy
	exec(N'select * from @ctname')
	*/

END

　　

USE mytest
GO

IF EXISTS ( select name from sysobjects where name = 'p_city_cnt' and type = 'P')
drop procedure p_city_cnt
GO

create procedure p_city_cnt
	@idx int,
	@idy int
AS
BEGIN

	--print 'solution - 2.1'
	create table #tmp (
		city_name varchar(100)
	)
	insert into #tmp(city_name) exec p_city @idx, @idy
	--select count(1) as number from #tmp
	select @@ROWCOUNT as number
	drop table #tmp

	/*
	--print 'solution - 2.2'
	declare @ctname table(
		city_name varchar(100)
	)
	insert into @ctname (city_name) exec p_city @idx, @idy
	select count(1) as number from @ctname
	*/
	/*
	-- solution 2.3.1, will response 2 result sets.
	declare @cnt int
	exec p_city @idx, @idy, @cnt out
	select @cnt as number

	-- solution 2.3.2, will response only one result set.
	create table #tmp (
		city_name varchar(100)
	)
	declare @cnt int
	insert into #tmp(city_name) exec p_city @idx, @idy, @cnt out
	select @cnt as number
	drop table #tmp
	*/
END