Question

如何通过跟随样本将多列转换为行？对于解决方案，我检查了许多样本，例如枢轴，解码等，但我没有达到绝对解决方案。

+---------+---------+---------+---------+
|  COL_1  |  COL_2  |  COL_3  |  COL_4  |
+---------+---------+---------+---------+

I wanna make columns like this;    

+---------+
|  COL_1  |
+---------+
|  COL_2  |
+---------+
|  COL_3  |
+---------+
|  COL_4  |
+---------+

Answer 1

也许你想要unpivot？

with demo as ( select 1 as col1, 2 as col2, 3 as col3, 4 as col4 from dual )
select * from demo
unpivot
( colvalue for col in (col1, col2, col3, col4) );

COL    COLVALUE
---- ----------
COL1          1
COL2          2
COL3          3
COL4          4

4 rows selected.

Answer 2

如果有像我这样的人正在寻找一种快速而肮脏的方法来在某处显示转置行，例如在Word或Excel中，通常只导出行会更容易，例如作为CSV，将CSV导入Excel，然后执行复制+特殊粘贴->在Excel中转置

Answer 3

这是 Tom Kyte 的方法 - 像 Postgres \G 或 MySQL +x 一样工作

https://asktom.oracle.com/pls/apex/f?p=100:11:0::::P11_QUESTION_ID:249321700346816237

ops$tkyte%ORA9IR2> create or replace type myScalarType as object
  2  ( rnum number, cname varchar2(30), val varchar2(4000) )
  3  /

Type created.

ops$tkyte%ORA9IR2> create or replace type myTableType as table of myScalarType
  2  /

Type created.

ops$tkyte%ORA9IR2>
ops$tkyte%ORA9IR2> create or replace
  2  function cols_as_rows( p_query in varchar2 ) return myTableType
  3  -- this function is designed to be installed ONCE per database, and
  4  -- it is nice to have ROLES active for the dynamic sql, hence the
  5  -- AUTHID CURRENT_USER
  6  authid current_user
  7  -- this function is a pipelined function -- meaning, it'll send
  8  -- rows back to the client before getting the last row itself
  9  -- in 8i, we cannot do this
 10  PIPELINED
 11  as
 12      l_theCursor     integer default dbms_sql.open_cursor;
 13      l_columnValue   varchar2(4000);
 14      l_status        integer;
 15      l_colCnt        number default 0;
 16      l_descTbl       dbms_sql.desc_tab;
 17      l_rnum          number := 1;
 18  begin
 19          -- parse, describe and define the query.  Note, unlike print_table
 20          -- i am not altering the session in this routine.  the
 21          -- caller would use TO_CHAR() on dates to format and if they
 22          -- want, they would set cursor_sharing.  This routine would
 23          -- be called rather infrequently, I did not see the need
 24          -- to set cursor sharing therefore.
 25      dbms_sql.parse(  l_theCursor,  p_query, dbms_sql.native );
 26      dbms_sql.describe_columns( l_theCursor, l_colCnt, l_descTbl );
 27      for i in 1 .. l_colCnt loop
 28          dbms_sql.define_column( l_theCursor, i, l_columnValue, 4000 );
 29      end loop;
 30
 31          -- Now, execute the query and fetch the rows.  Iterate over
 32          -- the columns and "pipe" each column out as a separate row
 33          -- in the loop.  increment the row counter after each
 34          -- dbms_sql row
 35      l_status := dbms_sql.execute(l_theCursor);
 36      while ( dbms_sql.fetch_rows(l_theCursor) > 0 )
 37      loop
 38          for i in 1 .. l_colCnt
 39          loop
 40              dbms_sql.column_value( l_theCursor, i, l_columnValue );
 41              pipe row
 42              (myScalarType( l_rnum, l_descTbl(i).col_name, l_columnValue ));
 43          end loop;
 44          l_rnum := l_rnum+1;
 45      end loop;
 46
 47          -- clean up and return...
 48      dbms_sql.close_cursor(l_theCursor);
 49      return;
 50  end cols_as_rows;
 51  /

Function created.

ops$tkyte%ORA9IR2>
ops$tkyte%ORA9IR2> select *
  2    from TABLE( cols_as_rows('select *
  3                                from emp
  4                               where rownum = 1') );

      RNUM CNAME                          VAL
---------- ------------------------------ --------------------
         1 EMPNO                          7369
         1 ENAME                          SMITH
         1 JOB                            CLERK
         1 MGR                            7902
         1 HIREDATE                       17-DEC-80
         1 SAL                            800
         1 COMM
         1 DEPTNO                         20

Oracle将列显示为行

3 个答案: