Oracle PL/SQL: Dump query result into file
I'm working on a pl sql stored procedure. What I need is to do a select, us开发者_如何转开发e a cursor and for every record build a string using values. At the end I need to write this into a file. I try to use dbms_output.put_line("toto") but the buffer size is to small because I have about 14 millions lines. I call my procedure from a unix ksh. I'm thinking at something like using "spool on" (on the ksh side) to dump the result of my procedure, but I don' know how to do it (if this is possible)
Anyone has any idea?
Unless it is really necessary, I would not use a procedure.
If you call the script using SQLPlus, just put the following into your test.sql
(the SET
s are from SQLPlus FAQ to remove noise):
SET ECHO OFF
SET NEWPAGE 0
SET SPACE 0
SET PAGESIZE 0
SET FEEDBACK OFF
SET HEADING OFF
SET TRIMSPOOL ON
SET TAB OFF
Select owner || ';' || object_name
From all_objects;
QUIT
and redirect output to a file (test.txt
):
sqlplus user/passwd@instance @ test.sql > test.txt
If you really need to do stuff in PL/SQL, consider putting that into a function and call it per record:
Create Or Replace Function calculate_my_row( in_some_data In Varchar2 )
Return Varchar2
As
Begin
Return in_some_data || 'something-complicated';
End calculate_my_row;
Call:
Select owner || ';' || calculate_my_row( object_name )
From all_objects;
Performance could suffer, but it should work. Make sure, that what you try can't be done in pure SQL
, though.
Reading your comment I think that Analytic Function Lag
is what you need.
This example appends *
in case the value of val
has changed:
With x As (
Select 1 id, 'A' val FROM dual
Union Select 2 id, 'A' val FROM dual
Union Select 3 id, 'B' val FROM dual
Union Select 4 id, 'B' val FROM dual
)
--# End of test-data
Select
id,
val,
Case When ( val <> prev_val Or prev_val Is Null ) Then '*' End As changed
From (
Select id, val, Lag( val ) Over ( Order By id ) As prev_val
From x
)
Order By id
Returns
ID V C
---------- - -
1 A *
2 A
3 B *
4 B
If every line of your output is the result of an operation on one row in the table, then a stored function, combined with Peter Lang's answer, can do what you need.
create function create_string(p_foobar foobar%rowtype) return varchar2 as
begin
do_some_stuff(p_foobar);
return p_foobar.foo || ';' ||p_foobar.bar;
end;
/
If it is more complicated than that, maybe you can use a pipelined table function
create type varchar_array
as table of varchar2(2000)
/
create function output_pipelined return varchar_array PIPELINED as
v_line varchar2(2000);
begin
for r_foobar in (select * from foobar)
loop
v_line := create_string(r_foobar);
pipe row(v_line);
end loop;
return;
end;
/
select * from TABLE(output_pipelined);
utl_file is your friend http://www.adp-gmbh.ch/ora/plsql/utl_file.html But is writes the data to the filesystem on the server so you probably need your DBA's help for this.
Tom Kyte has answered this, see
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from this question on Ask Tom
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