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关于按分数段统计的动态sql有关问题!

2012-01-19 
关于按分数段统计的动态sql问题!!!!!首先说明是 sql2k 不是sql2005现有学生成绩库0-100分每10分为一段或者

关于按分数段统计的动态sql问题!!!!!
首先说明是 sql2k 不是sql2005

现有学生成绩库0-100分
每10分为一段
或者每5分为一段,进行统计

分数段 人数 累计人数
[0-10] 20 20
[10-20] 30 50
[20-30] 40 90
[30-40] 50 140
...

0-10的意思是 0=<分数<10
10-20 的意思是 10<=分数<20

我知道可以写成这样
 select sum(case when 分数>=0 and 分数<10 then 1 else 0 end) '0-10',
....

但是现在想能够自动分分数段写成动态的语句怎么写。也就是给定一个参数比如10,就按10分一段,如果是5,就按5分一段,如果是20,就按20分一段。
oracle很容易实现,在sql2k里怎么实现,谢谢。



[解决办法]

SQL code
declare @sql varchar(8000)set @sql=''declare @i int;set @i=5select @sql=@sql+'sum(case when 分数>='+ltrim(number) +' and 分数<'+ltrim(number+@i)+ ' then 1 else 0 end) as ''['+ltrim(number)+'-'+ltrim(number+@i)+']'', ' from master..spt_valueswhere type='p' and number%@i=0and number between 0 and 95select 'select '+left(@sql,len(@sql)-1)+' from tablename'
[解决办法]
SQL code
declare @sql varchar(8000)declare @i intset @sql=''set @i=10select @sql=@sql+'sum(case when 分数>='+ltrim(@i*number) +' and 分数<'+ltrim(@i*number+@i)+ ' then 1 else 0 end) as ''['+ltrim(@i*number)+'-'+ltrim(@i*number+@i)+']'', ' from master..spt_valueswhere type='p' and @i*number<100select @sql='select '+stuff(@sql,len(@sql),1,'')+' from tb'print(@sql)
[解决办法]
SQL code
create table tb(score int)insert into tbselect 6 union allselect 11 union allselect 56 union allselect 37 union allselect 34 union allselect 87 union allselect 14 union allselect 66 union allselect 92 union allselect 41 union allselect 25 union allselect 10godeclare @sql varchar(8000)declare @i intset @i=5select @sql=isnull(@sql+',','')+'sum(case when score>='+ltrim(number) +' and score<'+ltrim(number+@i)+ ' then 1 else 0 end) as ['+ltrim(number)+'-'+ltrim(number+@i)+']'from master..spt_valueswhere type='p' and number%@i=0and number between 0 and 95select @sql = 'select '+@sql+' from tb'exec(@sql)drop table tb/***********0-5         5-10        10-15       15-20       20-25       25-30       30-35       35-40       40-45       45-50       50-55       55-60       60-65       65-70       70-75       75-80       80-85       85-90       90-95       95-100----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- -----------0           1           3           0           0           1           1           1           1           0           0           1           0           1           0           0           0           1           1           0(1 行受影响)
[解决办法]
探讨
还有没有别的法,分数段太多的话,8000字符不够。总分高中是750分的时候,初中是950分。

[解决办法]
SQL code
create table tb(score int)insert into tbselect 6 union allselect 11 union allselect 56 union allselect 37 union allselect 34 union allselect 87 union allselect 14 union allselect 66 union allselect 92 union allselect 41 union allselect 25 union allselect 950godeclare @str1 varchar(8000)declare @str2 varchar(8000)declare @i intset @i=5select @str1=isnull(@str1+',','')+'sum(case when score>='+ltrim(number) +' and score<'+ltrim(number+@i)+ ' then 1 else 0 end) as ['+ltrim(number)+'-'+ltrim(number+@i)+']'from master..spt_valueswhere type='p' and number%@i=0and number between 0 and 550select @str2=isnull(@str2+',','')+'sum(case when score>='+ltrim(number) +' and score<'+ltrim(number+@i)+ ' then 1 else 0 end) as ['+ltrim(number)+'-'+ltrim(number+@i)+']'from master..spt_valueswhere type='p' and number%@i=0and number between 550+@i and 950print len(@str1)  --看字符串长度print len(@str1)/(550/@i)  --看每个分段用的字符串长度print 950/@i*70  --看按950分算@i长度分段用的总字符串长度exec('select '+@str1+','+@str2+' from tb')drop table tb/********************7796  --@str1长度70    --每段长度13300 --总长度0-5         5-10        10-15       15-20       20-25       25-30       30-35       35-40       40-45       45-50       50-55       55-60       60-65       65-70       70-75       75-80       80-85       85-90       90-95       95-100      100-105     105-110     110-115     115-120     120-125     125-130     130-135     135-140     140-145     145-150     150-155     155-160     160-165     165-170     170-175     175-180     180-185     185-190     190-195     195-200     200-205     205-210     210-215     215-220     220-225     225-230     230-235     235-240     240-245     245-250     250-255     255-260     260-265     265-270     270-275     275-280     280-285     285-290     290-295     295-300     300-305     305-310     310-315     315-320     320-325     325-330     330-335     335-340     340-345     345-350     350-355     355-360     360-365     365-370     370-375     375-380     380-385     385-390     390-395     395-400     400-405     405-410     410-415     415-420     420-425     425-430     430-435     435-440     440-445     445-450     450-455     455-460     460-465     465-470     470-475     475-480     480-485     485-490     490-495     495-500     500-505     505-510     510-515     515-520     520-525     525-530     530-535     535-540     540-545     545-550     550-555     555-560     560-565     565-570     570-575     575-580     580-585     585-590     590-595     595-600     600-605     605-610     610-615     615-620     620-625     625-630     630-635     635-640     640-645     645-650     650-655     655-660     660-665     665-670     670-675     675-680     680-685     685-690     690-695     695-700     700-705     705-710     710-715     715-720     720-725     725-730     730-735     735-740     740-745     745-750     750-755     755-760     760-765     765-770     770-775     775-780     780-785     785-790     790-795     795-800     800-805     805-810     810-815     815-820     820-825     825-830     830-835     835-840     840-845     845-850     850-855     855-860     860-865     865-870     870-875     875-880     880-885     885-890     890-895     895-900     900-905     905-910     910-915     915-920     920-925     925-930     930-935     935-940     940-945     945-950     950-955----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- -----------0           1           2           0           0           1           1           1           1           0           0           1           0           1           0           0           0           1           1           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           0           1(1 行受影响) 

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