I am trying to format data returned from a cursor to JSON by looping through the records and columns without having to explicitly call on each column name. From what I've researched this vary well may not be a simple task or at least as simple as I'm trying to make it. I'm wondering if anyone else has tried a similar approach and if they had any luck.
declare
type type_cur_tab is table of employees%rowtype
index by PLS_integer;
type type_col_tab is table of varchar2(1000)
index by binary_integer;
tbl_rec type_cur_tab;
tbl_col type_col_tab;
begin
select * BULK COLLECT INTO tbl_rec
from employees;
select column_name BULK COLLECT INTO tbl_col
from all_tab_columns
where UPPER(table_name) = 'EMPLOYEES';
for i IN 1..tbl_rec.COUNT Loop
for j IN 1..tbl_col.count Loop
dbms_output.put_line(tbl_rec(i).tbl_col(j));
end loop;
end loop;
end;
It throws an error saying 'tbl_col' must be declared. I'm sure this is bc it's looking for 'tbl_col' listed inside 'tbl_rec'. Any help is greatly appreciated.
NOTE: I'm aware of the built in JSON conversion but I haven't been able to get it to as fast as I'd like so I'm trying to loop through and add the appropriate formatting along the way.
It is impossible to specify field of tbl_rec(i) in this manner.
Try this:
declare
v_cur sys_refcursor;
col_cnt number;
desc_t dbms_sql.desc_tab;
c number;
vVarchar varchar2(32000);
vNumber number;
vDate date;
v_result clob:='';
rn number:=0;
begin
--Any sql query or pass v_cur as input parameter in function on procedure
open v_cur for
select * from dual;
--------
c:=dbms_sql.to_cursor_number(v_cur);
dbms_sql.describe_columns(c => c, col_cnt => col_cnt, desc_t => desc_t);
for i in 1 .. col_cnt
loop
case desc_t(i).col_type
when dbms_types.TYPECODE_DATE then
dbms_sql.define_column(c, i ,vDate);
when dbms_types.TYPECODE_NUMBER then
dbms_sql.define_column(c, i ,vNumber);
else
dbms_sql.define_column(c, i ,vVarchar,32000);
end case;
end loop;
v_result:='{"rows":{ "row": [';
while (dbms_sql.fetch_rows(c)>0)
loop
if rn > 1 then v_result:=v_result||','; end if;
v_result:=v_result||'{';
for i in 1 .. col_cnt
loop
if (i>1) then v_result:=v_result||','; end if;
case desc_t(i).col_type
--Date
when dbms_types.typecode_date then
dbms_sql.column_value(c,i,vDate);
v_result:=v_result||' "'||desc_t(i).col_name||'" :"'||to_char(vDate,'dd.mm.yyyy hh24:mi')||'"';
--Number
when dbms_types.typecode_number then
dbms_sql.column_value(c,i,vNumber);
v_result:=v_result||' "'||desc_t(i).col_name||'" :"'||to_char(vNumber)||'"';
--Varchar - default
else
dbms_sql.column_value(c,i,vVarchar);
v_result:=v_result||' "'||desc_t(i).col_name||'" :"'||vVarchar||'"';
end case;
end loop;
v_result:=v_result||'}';
end loop;
v_result:=v_result||']}}';
dbms_output.put_line (v_result);
end;
Also you can generate XML from ref cursor with DBMS_XMLGEN package and then translate xml into json with xslt transformation.
Related
I want to make a statement in netezza so that it waits until a statement is correct before proceeding. Any help would be appreciated - something similar to the below
WHILE (
select count(*) EVENT_DESCRIPTION from TEST_DA_CONTROL.CTRL.C_DBA_MAINTENANCE_AUDIT
where EVENT_DESCRIPTION = 'STARTED' and DATETIME_LOGGED > (select add_months(current_date,0))) = 0
LOOP
wait 5
end loop;
but I don't know the correct syntax.
Best to assign that output to a variable. I seem to recall that getting data out of an execute immediate is a little arduous in nzplsql, but there are convenient variables already available for you to use. Here I'll use ROW_COUNT.
declare
event_descriptions int;
sql varchar;
begin
event_descriptions := 1;
while event_descriptions > 0 loop
--Actual work
sql := '
select * EVENT_DESCRIPTION from TEST_DA_CONTROL.CTRL.C_DBA_MAINTENANCE_AUDIT
where EVENT_DESCRIPTION = ''STARTED'' and DATETIME_LOGGED > (select add_months(current_date,0))) = 0;';
execute immediate sql;
event_descriptions := ROW_COUNT;
end loop;
end;
I am new to PLSQL. I am trying to create a procedure which iterates through an array.
My requirement is if one of the value is not found in table, it should add into FAILARRAY, otherwise it should add into PASSARRAY.
I was getting no data found exception even if it is handled, it goes out of the loop and next value in the loop is not getting iterated again.
Is there any way we can use if exists command here. Please help.
CREATE OR REPLACE PROCEDURE SCHEMA.PR_VALIDATE
(
FILEARRAY IN STRARRAY,
PASSARRAY OUT STRARRAY,
FAILARRAY OUT STRARRAY,
)
IS
--DECLARE
fileName VARCHAR2 (50);
fileId NUMBER;
BEGIN
for i in 1 .. FILEARRAY.count
loop
fileName := FILEARRAY(i);
DBMS_OUTPUT.put_line (FILEARRAY (i));
SELECT FILEID into fileId FROM TABLE_NAME WHERE FILENAME=fileName;
end loop
END;
I suspect you haven't realised that you can have a PL/SQL BEGIN ... END block, including an exception handler, within a loop. In fact, anywhere you can have PL/SQL statements you can have a block.
You mention an exception handler, although your code doesn't contain one. As you say your code goes 'out of the loop', I can only assume it's, well, outside of the for loop. But you can easily add a block, with an exception handler, inside the for loop, for example:
BEGIN
for i in 1 .. FILEARRAY.count
loop
fileName := FILEARRAY(i);
DBMS_OUTPUT.put_line (FILEARRAY (i));
-- Inner block starts at the line below:
BEGIN
SELECT FILEID into fileId FROM TABLE_NAME WHERE FILENAME=fileName;
-- TODO add to PASSARRAY
EXCEPTION
WHEN NO_DATA_FOUND THEN
-- TODO add to FAILARRAY
END;
end loop
END;
This way, if there are 8 values in FILEARRAY and no data is found in the table for the third value, the NO_DATA_FOUND exception gets caught without exiting the loop and the loop then progresses to the fourth value in FILEARRAY.
You are handling the exception but you need to avoid the exception. Try:
SELECT NVL(FILEID, "<Put Something here or leave it empty") FROM TABLE_NAME WHERE FILENAME=fileName;
That way if it finds a null value in the select it will just pull "" instead. Then you can check to see if your SELECT returns "" and if so populate your FAILARRAY, otherwise populate PASSARRAY.
CREATE OR REPLACE PROCEDURE SCHEMA.PR_VALIDATE(
FILEARRAY IN STRARRAY,
PASSARRAY OUT STRARRAY,
FAILARRAY OUT STRARRAY )
IS
fileName VARCHAR2 (50);
l_n_count NUMBER;
l_n_file_id NUMBER;
BEGIN
FOR i IN 1 .. FILEARRAY.count
LOOP
fileName := FILEARRAY(i);
DBMS_OUTPUT.put_line (FILEARRAY(i));
SELECT COUNT(FILEID) INTO l_n_count FROM TABLE_NAME WHERE FILENAME=fileName;
IF l_n_count =0 THEN
failarray(i):='No Value Found';
elsif l_n_count=1 THEN
SELECT FILEID INTO l_n_file_id FROM TABLE_NAME WHERE FILENAME=fileName;
Passarray(i):=l_n_file_id;
END IF;
END LOOP;
END;
/
I have the following problem. I'm trying to check a number (bsn), if it's in the database or not. If it's not in the database it should give me an error, however now I'm getting always an error even if the number exists in the database. It worked fine with only one number in the database, but with more... That's the problem. Oh and I'm working with APEX, so I use this as a process.
create or replace PROCEDURE CONTROLE_BSN IS
CURSOR c_klanten
IS
SELECT bsn
FROM klant;
v_bsn VARCHAR2(10) := V('P7_BSN');
e_geen_bsn EXCEPTION;
BEGIN
FOR r_record IN c_klanten
LOOP
IF r_record.bsn != v_bsn THEN
RAISE e_geen_bsn;
END IF;
END LOOP;
EXCEPTION
WHEN e_geen_bsn THEN
raise_application_error(-20001, 'This bsn-number does not exists.');
END CONTROLE_BSN;
Your logic is flowed. As soon as you have two different bsn in your table, your test will be true for at least one of them:
FOR r_record IN c_klanten
LOOP
IF r_record.bsn != v_bsn THEN --< when N different records,
-- this is true for at least N-1 of them
RAISE e_geen_bsn;
END IF;
END LOOP;
Maybe you should go for something a little bit simpler than that. Why not write your cursor like this instead:
CURSOR c_klanten
IS
SELECT count(*) n
FROM klant
WHERE nbc = v_bsn;
That way, you will easily get the number of matching bsn. Either 0, 1 or more. And then perform the appropriate action.
Perhaps the following would help:
create or replace PROCEDURE CONTROLE_BSN IS
CURSOR c_klanten(p_bsn) IS
SELECT count(*) as bsn_count
FROM klant
where bsn = p_bsn;
v_bsn VARCHAR2(10) := V('P7_BSN');
e_geen_bsn EXCEPTION;
BEGIN
FOR r_record IN c_klanten(v_bsn)
LOOP
IF r_record.bsn_count = 0 THEN
RAISE e_geen_bsn;
END IF;
END LOOP;
EXCEPTION
WHEN e_geen_bsn THEN
raise_application_error(-20001, 'This bsn-number does not exists.');
END CONTROLE_BSN;
Best of luck.
I'm trying to do something very basic in PL/SQL, but I keep getting owned... how do I push items into an array and iterate through them?
Googling it seems to suggest using owa_text.multi_line;
owa_text.multi_line is a record of this type:
/* A multi_line is just an abstract datatype which can hold */
/* large amounts of text data as one piece. */
type multi_line is record
(
rows vc_arr,
num_rows integer,
partial_row boolean
);
To iterate through vc_arr, we have to use l_array.first.. l_array.last. But that gives an error while trying to access it.
Here's a simple sample to find load distinct values into an array:
declare
l_persons owa_text.multi_line := owa_text.new_multi();
/* Documentation of owa_text.new_multi(): Standard "make element" routines. */
--function new_multi return multi_line;
l_value_exists boolean := false;
cursor c_get_orders is
select person,
choice
from my_orders;
begin
for i in c_get_orders loop
l_value_exists := false;
for j in l_persons.rows.first.. l_persons.rows.last loop --Fails here,
--PL/SQL: numeric or value error
if l_persons.rows(j) = i.person then
l_value_exists := true;
exit;
end if;
end loop;
if not l_value_exists then
owa_text.add2multi(i.person, l_persons);
end if;
end loop;
for i in l_persons.rows.first.. l_persons.rows.last loop
write_to_log(l_persons.rows(i));
end loop;
end;
What am I missing? How do I do this?
EDIT: Here's a script to get set up, if it helps follow the example:
create table my_orders
(
person varchar2(4000 byte),
choice varchar2(4000 byte)
);
insert into my_orders
(person, choice)
values
('Tom', 'Juice');
insert into my_orders
(person, choice)
values
('Jane', 'Apple');
insert into my_orders
(person, choice)
values
('Tom', 'Cake');
insert into my_orders
(person, choice)
values
('Jane', 'Chocolate');
insert into my_orders
(person, choice)
values
('Tom', 'Coffee');
commit;
Presumable, the new_multi() method initializes an empty collection.
One of the more esoteric features of Oracle collections is that using FIRST / LAST to iterate over empty collections doesn't work - you have to either check whether the collection is empty, or use 1 .. <collection>.COUNT instead:
declare
type t_number_nt is table of number;
l_numbers t_number_nt := t_number_nt();
begin
-- raises ORA-006502
/* for i in l_numbers.first .. l_numbers.last
loop
dbms_output.put_line(l_numbers(i));
end loop;
*/
-- doesn't raise an error
for i in 1 .. l_numbers.count loop
dbms_output.put_line(l_numbers(i));
end loop;
end;
UPDATE
For a more thorough explanation of techniques for iterating over PL/SQL collections, see this OTN article by Steven Feuerstein
It has to be like this:
declare
l_persons owa_text.multi_line;
begin
OWA_TEXT.new_multi (l_persons);
FOR i IN 1 .. l_persons.num_rows
loop
null;
end loop;
end;
I have a parameter table with 10 rows. Called parameter_table.
In my PL/SQL procedure, I do loop in 2 million records. And each time querying this parameter table too.
I want to load this parameter table in to the memory and decrease the I/O process.
What is the best way to do this?
FOR cur_opt
IN (SELECT customer_ID,
NVL (customer_type, 'C') cus_type
FROM invoice_codes
WHERE ms.invoice_type='RT')
LOOP
....
...
Select data From parameter_table Where cus_type = cur_opt.cus_type AND cr_date < sysdate ; -- Where clause is much complex than this..
....
...
END LOOP;
You can just join it to your main query:
select customer_id, data
from parameter_table t, invoice_codes c
where t.cus_type = nvl(c.customer_type, 'C')
and t.cr_date < sysdate
However, if you've got 2 million records in invoice_codes, then joining to the parameter table is the least of your concerns - looping through this will take some time (and is probably the real cause of your I/O problems).
I Think you may change the query ,joining to parameter_table, so there will be no need to hit the select statement inside the loop. (like what #Chris Saxon solution)
But as a way to use cashed data,
You could fill a dictionary like, array and then refer it when necessary
Something like this may help:
you have to call Fill_parameters_cash before starting the main process and call get_parameter to fetch the data, the input parameter to call get_parameter is the dictionary key
TYPE ga_parameter_t IS TABLE OF parameter_table%ROWTYPE INDEX BY BINARY_INTEGER;
ga_parameter ga_parameter_t;
procedure Fill_parameters_cash is
begin
ga_parameter.DELETE;
SELECT * BULK COLLECT
INTO ga_parameter
FROM parameter_table;
end Fill_parameters_cash;
FUNCTION get_parameter(cus_type invoice_codes.cus_type%TYPE,
is_fdound OUT BOOLEAN)
RETURN parameter_table%ROWTYPE IS
result_value parameter_table%ROWTYPE;
pos NUMBER;
BEGIN
result_value := NULL;
is_fdound := FALSE;
IF cus_type IS NULL THEN
RETURN NULL;
END IF;
pos := ga_parameter.FIRST;
WHILE pos IS NOT NULL
LOOP
EXIT WHEN ga_parameter(pos).cus_type = cus_type;
pos := ga_parameter.NEXT(pos);
END LOOP;
IF pos IS NOT NULL THEN
is_fdound := TRUE;
result_value := ga_parameter(pos);
END IF;
RETURN result_value;
END get_parameter;
I'd guess looping through a million records is already causing issues. Not quite sure how this parameter table lookup is really worsening it.
Anyways, if this is really the only approach you can take, then you could do an inner or outer join in the cursor declaration.
----
FOR cur_opt
IN (SELECT customer_ID,
NVL (customer_type, 'C') cus_type
FROM invoice_codes codes,
parameter_table par
WHERE ms.invoice_type='RT'
and codes.cus_type = par.cus_type -- (or an outer join) maybe?
) loop
..........