Oracle表或者视图的行转列[练习]

--行转列函数 2014年7月17日 16:15:18
Function Fn_Row_To_Col(tabname         in varchar2, --需要进行行转列操作的表名或者视图；
group_col       in varchar2, --查询结果要按某列或某些列分组的字段名；
column_col      in varchar2, -- 要从行转成列的字段；
value_col       in varchar2, -- 需要聚合的值字段；
Aggregate_func  in varchar2 default 'max', -- 选用的聚合函数，可选，默认为max；
colorder        in varchar2 default null, -- 行转列后列的排序，可选；
roworder        in varchar2 default null, -- 行转列后记录的排序，可选；
when_value_null in varchar2 default null,-- 若value_col字段的值聚合后为空，则转换成该值，可选；
where_str in varchar2 default null,--对tabname的查询条件，可选
rowcount_str  in varchar2 default null--,--对tabname进行行统计，可选(合计、2099-12-31)
)
return sys_refcursor
as
sqlstr varchar2(4000) := 'select ' || group_col || ' ';
c1     sys_refcursor;
v1     varchar2(100);
tempstr varchar2(4000):='';
rowsqlstr varchar2(4000):='';
cur    sys_refcursor;
begin
If rowcount_str is not null then--如果tabname进行行统计的条件不为空则进行统计
rowsqlstr:=rowsqlstr||sqlstr||','||column_col||','||value_col||' from '||tabname||' '||where_str||' union '||
sqlstr||','''||rowcount_str||''' '||column_col||','||Aggregate_func||'('||value_col||') '||value_col||' from '||tabname
||' '||where_str||' group by '||group_col;
tempstr:=tempstr||'select distinct ' || column_col || ' from ( '|| rowsqlstr||' ) '||(case when colorder is not null then ' order by ' || colorder  end);
Else
tempstr:=tempstr||'select distinct ' || column_col || ' from ' || tabname||' '||where_str||(case when colorder is not null then ' order by ' || colorder  end);
End If;

open c1 for tempstr;
loop fetch c1  into v1;
exit when c1%notfound;
sqlstr := sqlstr || chr(10) || ',' || case when when_value_null is not null then
'nvl(' end || Aggregate_func || '(decode(to_char(' || column_col ||'),''' || v1 || ''',' || value_col || '))'
|| case  when when_value_null is not null then chr(44) || when_value_null || chr(41)  end || '"' || v1 || '"';
end loop;
close c1;
tempstr:=sqlstr || ' from ' || case when rowcount_str is not null then '( '||rowsqlstr||' )' else tabname end||' group by ' || group_col || case when roworder is not null then ' order by ' || roworder end;
--DBMS_OUTPUT.put_line(length(tempstr));--查看是否超过4000个字符
open cur for tempstr;
return cur;
end Fn_Row_To_Col;

--执行查询
Select
PKG_STM_GETDATA_TABLE.Fn_Row_To_Col(tabname =>'VW_DAYRPT_STDTSK_R',
group_col => 'DPTKEY,DPTCNNAME,PARTKEY,PARTMCODE,PARTNAME,LABOURKEY,LABOURCODE,LABOURNAME',
column_col => 'DAYRPTDATE',
value_col => 'PRODTIME',
aggregate_func =>'Sum',
colorder =>'DAYRPTDATE asc',
roworder =>'DPTKEY asc,LABOURCODE asc,PARTKEY asc',
when_value_null =>null,
where_str => ' where DAYRPTDATE>=''2014-05-28'' and DAYRPTDATE<=''2014-06-28''',
rowcount_str => '合计')
from dual;

备注：程序中可以使用存储过程

Procedure Sp_Row_To_Col(tabname in varchar2, --需要进行行转列操作的表名或者视图；
group_col in varchar2, --查询结果要按某列或某些列分组的字段名；
column_col in varchar2, -- 要从行转成列的字段；
value_col in varchar2, -- 需要聚合的值字段；
Aggregate_func in varchar2 default 'max', -- 选用的聚合函数，可选，默认为max；
colorder in varchar2 default null, -- 行转列后列的排序，可选；
roworder in varchar2 default null, -- 行转列后记录的排序，可选；
when_value_null in varchar2 default null,-- 若value_col字段的值聚合后为空，则转换成该值，可选；
where_str in varchar2 default null,--对tabname的查询条件，可选
rowcount_str in varchar2 default null,--对tabname进行行统计，可选(合计、2099-12-31)
cur out sys_refcursor--以游标的形式、返回数据集
)
as
sqlstr varchar2(4000) := 'select ' || group_col || ' ';
c1 sys_refcursor;
v1 varchar2(100);
tempstr varchar2(4000):='';
rowsqlstr varchar2(4000):='';
--cur sys_refcursor;
begin
If rowcount_str is not null then--如果tabname进行行统计的条件不为空则进行统计
rowsqlstr:=rowsqlstr||sqlstr||','||column_col||','||value_col||' from '||tabname||' '||where_str||' union '||
sqlstr||','''||rowcount_str||''' '||column_col||','||Aggregate_func||'('||value_col||') '||value_col||' from '||tabname
||' '||where_str||' group by '||group_col;
tempstr:=tempstr||'select distinct ' || column_col || ' from ( '|| rowsqlstr||' ) '||(case when colorder is not null then ' order by ' || colorder end);
Else
tempstr:=tempstr||'select distinct ' || column_col || ' from ' || tabname||' '||where_str||(case when colorder is not null then ' order by ' || colorder end);
End If;

open c1 for tempstr;
loop fetch c1 into v1;
exit when c1%notfound;
sqlstr := sqlstr || chr(10) || ',' || case when when_value_null is not null then
'nvl(' end || Aggregate_func || '(decode(to_char(' || column_col ||'),''' || v1 || ''',' || value_col || '))'
|| case when when_value_null is not null then chr(44) || when_value_null || chr(41) end || '"' || v1 || '"';
end loop;
close c1;
tempstr:=sqlstr || ' from ' || case when rowcount_str is not null then '( '||rowsqlstr||' )' else tabname end||' group by ' || group_col || case when roworder is not null then ' order by ' || roworder end;
--DBMS_OUTPUT.put_line(length(tempstr));--查看是否超过4000个字符
open cur for tempstr;
end Sp_Row_To_Col;