I have a procedure in which I want to fetch all records from cte into Names variable. But this code is not writing into names from CTE. How can I fetch records into names so that I can later loop through names and get content of field_name?
CREATE OR REPLACE PROCEDURE sp_market
IS
Names VARCHAR2(32767);
BEGIN
WITH CTE(sqql) As
(
SELECT field_name sqql FROM pld_medicare_config
)
SELECT sqql into Names from CTE;
END sp_market;
SELECT sqql into Names from CTE;
You are assigning multiple rows returned from table to a variable, which will fail.
You could simply use a CURSOR FOR LOOP which will create an implicit cursor and you can loop through the names:
CREATE OR REPLACE PROCEDURE sp_market IS
BEGIN
FOR i IN (
SELECT field_name
FROM pld_medicare_config
)
LOOP
-- Your logic goes here
dbms_output.put_line(i.field_name);
END LOOP;
END;
/
I think your best bet is to create a associative array and use BULK COLLECT to populate the table. In its simplest form, the code would look like this:
CREATE OR REPLACE PROCEDURE sp_market IS
TYPE lt_names IS TABLE OF VARCHAR2(32767) INDEX BY PLS_INTEGER;
l_tNames lt_names;
BEGIN
SELECT field_name
BULK COLLECT INTO l_tNames
FROM pld_medicare_config
IF l_tNames.COUNT() > 0 THEN
FOR i IN l_tNames.FIRST..l_tNames.LAST LOOP
NULL; --REPLACE WITH YOUR LOGIC
END LOOP;
END IF;
END;
/
A few notes:
I'm assuming that you've set MAX_STRING_SIZE to EXTENDED. Otherwise, you'll have an issue with VARCHAR2 that big.
As I said, that is the simplest way to do this. If you're expecting a huge result set, you'll want to look into chunking it up. This Oracle blog post is very helpful in giving you multiple options for how to perform bulk processing. (Blog Post)
Related
I want to create procedure, that will use cursor, which is the same for arbitrary tables. My current one looks like this:
create or replace
PROCEDURE
some_name(
p_talbe_name IN VARCHAR2,
p_chunk_size IN NUMBER,
p_row_limit IN NUMBER
) AS
CURSOR v_cur IS
SELECT common_column,
ora_hash(substr(common_column, 1, 15), p_chunk_size) as chunk_number
-- Here it can find the table!
FROM p_table_name;
TYPE t_sample IS TALBE OF v_cur%rowtype;
v_sample t_sample;
BEGIN
OPEN v_cur;
LOOP FETCH v_cur BULK COLLECT INTO v_sample LIMIT p_row_limit;
FORALL i IN v_sample.first .. v_sample.last
INSERT INTO chunks VALUES v_sample(i);
COMMIT;
EXIT WHEN v_cur%notfound;
END LOOP;
CLOSE v_cur;
END;
The problem is that it cannot find the table named p_table_name which I want to parametrize. The thing is that I need to create chunks based on hashes for common_column which exists in all intended tables. How to deal with that problem? Maybe there is the equivalent oracle code that will do the same thing? Then I need the same efficiency for the query. Thanks!
I would do this as a single insert-as-select statement, complicated only by the fact you're passing in the table_name, so we need to use dynamic sql.
I would do it something like:
CREATE OR REPLACE PROCEDURE some_name(p_table_name IN VARCHAR2,
p_chunk_size IN NUMBER,
p_row_limit IN NUMBER) AS
v_table_name VARCHAR2(32); -- 30 characters for the tablename, 2 for doublequotes in case of case sensitive names, e.g. "table_name"
v_insert_sql CLOB;
BEGIN
-- Sanitise the passed in table_name, to ensure it meets the rules for being an identifier name. This is to avoid SQL injection in the dynamic SQL
-- statement we'll be using later.
v_table_name := DBMS_ASSERT.ENQUOTE_LITERAL(p_table_name);
v_insert_sql := 'insert into chunks (common_column_name, chunk_number)'||CHR(10)|| -- replace the column names with the actual names of your chunks table columns.
'select common_column,'||CHR(10)||
' ora_hash(substr(common_column, 1, 15), :p_chunk_size) AS chunk_number'||CHR(10)||
'from '||v_table_name||CHR(10)||
'where rownum <= :p_row_limit';
-- Used for debug purposes, so you can see the definition of the statement that's going to be run.
-- Remove before putting the code in production / convert to proper logging code:
dbms_output.put_line(v_insert_sql);
-- Now run the statement:
EXECUTE IMMEDIATE v_insert_sql USING p_chunk_size, p_row_limit;
-- I've included the p_row_limit in the above statement, since I'm not sure if your original code loops through all the rows once it processes the
-- first p_row_limit rows. If you need to insert all rows from the p_table_name into the chunks table, remove the predicate from the insert sql and the extra bind variable passed into the execute immediate.
END some_name;
/
By using a single insert-as-select statement, you are using the most efficient way of doing the work. Doing the bulk collect (which you were using) would use up memory (storing the data in the array) and cause extra context switches between the PL/SQL and SQL engines that the insert-as-select statement avoids.
Say I have a stored procedure which accepts 2 varchars, does some processing and updates my business tables. Is there a way that I can run the stored procedure for the results from a select query?
Like,
execute my_stored_proc select varchar_1,varchar_2 from an_ip_table;
You can iterate over results by loop
BEGIN
FOR RECS IN (SELECT varchar_1, varchar_2 FROM an_ip_table)
LOOP
my_stored_proc (RECS.varchar_1, RECS.varchar_2);
END LOOP;
END
This could be a simple way:
begin
for i in (
select varchar_1, varchar_2
from an_ip_table
)
loop
my_stored_proc(i.varchar_1, i.varchar_2);
end loop;
end;
Initially, I thought of just to put a comment, but this needs some explanation, so I'm writing an answer. You are actually doing it the wrong way. Ideally, you should be passing a cursor to your my_stored_proc and fetching the cursor inside the procedure. Your method actually causes multiple calls to procedure for every row from the query result. The processing will be very slow if you have huge volume of data. It is a bad idea even if there are few rows.
Here is a sample procedure that does a dml operation using FORALL.It is just a sample, but you should be able to convert your select query such that you should be able to do dml this way.
CREATE OR REPLACE PROCEDURE my_stored_proc (
p_iptab_cur SYS_REFCURSOR
) AS
TYPE iprec IS RECORD ( col1 an_ip_table.col1%TYPE,
col2 an_ip_table.col1%TYPE );
TYPE iptype IS
TABLE OF iprec;
ips iptype;
BEGIN
FETCH p_iptab_cur BULK COLLECT INTO ips;
FORALL i IN ips.FIRST..ips.LAST
--Your DML-- using the collection of records.
END;
/
--Calling the procedure by passing the `CURSOR`
DECLARE
x SYS_REFCURSOR;
BEGIN
OPEN x FOR select col1, col2
from an_ip_table;
my_stored_proc(x);
END;
/
say i have the table XX_TEST_DATA and its being used to populate a nested table inside a PL/SQL block below (please note the comments):
DECLARE
CURSOR XX_DATA_CUR
IS
SELECT *
FROM XX_TEST_DATA;
TYPE TYP_XX_TEST IS TABLE OF XX_TEST_DATA%ROWTYPE INDEX BY PLS_INTEGER;
XX_REC TYP_XX_TEST;
BEGIN
OPEN XX_DATA_CUR;
FETCH XX_DATA_CUR
BULK COLLECT
INTO XX_REC;
CLOSE XX_DATA_CUR;
for i in 1..XX_REC.count loop
XX_REC(i).BATCH_NAME := 'Batch 1'; -- This is the Line
end loop;
END;
I would like to assign the value "Batch 1" to ALL records inside the nested table. Would this be possible without looping through all the records?
Something like below:
BEGIN
OPEN XX_DATA_CUR;
FETCH XX_DATA_CUR
BULK COLLECT
INTO XX_REC;
CLOSE XX_DATA_CUR;
XX_REC.BATCH_NAME := 'Batch 1'; --
END;
I know the above block would not work, but I was hoping to achive something like that.
DDL of the Test Table
Create table XX_TEST_DATA
(
XX_ID NUMBER
, XX_DATA1 VARCHAR2(100)
, XX_DATA2 VARCHAR2(100)
, BATCH_NAME VARCHAR2(100)
);
The value could be set as part of the SELECT and then there would be no need to update the collection.
DECLARE
TYPE TYP_XX_TEST IS TABLE OF XX_TEST_DATA%ROWTYPE INDEX BY PLS_INTEGER;
XX_REC TYP_XX_TEST;
BEGIN
SELECT XX_ID, XX_DATA1, XX_DATA2, 'Batch 1'
BULK COLLECT INTO XX_REC
FROM XX_TEST_DATA;
END;
/
I'm writing a function that needs to manipulate multiple rows at the same time and they need to be indexed. After several hours of reading about Oracle pl/sql I figured I could create a nested table kind of collection. Since I couldn't find a definitive answer and trial/error method takes way to long.
Here is question part:
QUESTION: What is the best practice to populate a nested table collection? Oracle PL/SQL
type partsTable is table of Parts_north_wing%rowtype;
pt PartsTable;
index number;
cursor pCursor is select * from Parts_north_wing;
begin
index := 1;
open pCursor;
loop
fetch pCursor into tempRow;
pt(index) := tempRow;
index := index + 1;
exit when pCursor%notfound;
end loop;
close pCursor;
A cursor FOR LOOP is almost always the best way to process rows in PL/SQL. It's simpler than the OPEN/FETCH/CLOSE method - no need to declare variables and manipulate cursors. It's also faster since it automatically bulk collects the results.
begin
for pt in
(
select parts_north_wing.*, rownum row_index
from parts_north_wing
) loop
--Do something here
null;
end loop;
end;
/
Try this. Hope this helps you to clear some of your concepts.
--Create a dummy object tyep
CREATE OR REPLACE TYPE av_obj
IS
OBJECT
(
ADD1 VARCHAR2(100),
ADD2 VARCHAR2(100) );
--Create a nested tale type
CREATE OR REPLACE TYPE AV_TT
IS
TABLE OF AV_OBJ;
--Bulk collect into nested table type
DECLARE
av_nested_tab AVROY.AV_TT;
BEGIN
SELECT avroy.av_obj(LEVEL
||'add1',LEVEL
||'add2') BULK COLLECT
INTO av_nested_tab
FROM DUAL
CONNECT BY LEVEL < 10;
END;
I'm having a heck of a time trying to find an example of this being done. I have a procedure, and as part of that procedure I want to store the results of a SELECT statement so that I can work against that set, and then use it as a reference to update the original records when it's all done.
The difficulty I'm having is in declaring the temporary table variable. Here's an example of what I'm trying to do:
PROCEDURE my_procedure
IS
output_text clob;
temp_table IS TABLE OF MY_TABLE%ROWTYPE; -- Error on this line
BEGIN
SELECT * BULK COLLECT INTO temp_table FROM MY_TABLE WHERE SOME_DATE IS NULL;
-- Correlate results into the clob for sending to email (working)
-- Set the SOME_DATE value of the original record set where record is in temp_table
I get an error on the second occurrence of IS, saying that it is an unexpected symbol. This suggests to me that my table variable declaration is either wrong, or in the wrong place. I've tried putting it into a DECLARE block after BEGIN, but I just get another error.
Where should this declaration go? Alternatively, if there is a better solution I'll take that too!
CREATE OR REPLACE PROCEDURE PROCEDURE1 AS
output_text clob;
type temp_table_type IS TABLE OF MY_TABLE%ROWTYPE;
temp_table temp_table_type;
BEGIN
SELECT * BULK COLLECT INTO temp_table FROM MY_TABLE;
END PROCEDURE1;
or
CREATE OR REPLACE PROCEDURE PROCEDURE1 ( output_text OUT clob ) IS
type temp_table_type IS TABLE OF MY_TABLE%ROWTYPE
INDEX BY BINARY_INTEGER;
temp_table temp_table_type;
BEGIN
SELECT * BULK COLLECT INTO temp_table FROM MY_TABLE;
FOR indx IN 1 .. temp_table.COUNT
LOOP
something := temp_table(indx).col_name;
END LOOP;
END PROCEDURE1;
I had a similiar problem and found this:
Selecting Values from Oracle Table Variable / Array?
The global temporary table can be used like a regular table, but its content is only temporary (deleted at end of session/transaction) and each session has its own table content.
If you don't need dynamic SQL this can be used as good solution:
CREATE GLOBAL TEMPORARY TABLE temp_table
(
column1 NUMBER,
column2 NUMBER
)
ON COMMIT DELETE ROWS;
PROCEDURE my_procedure
IS
output_text clob;
BEGIN
-- Clear temporary table for this session (to be sure)
DELETE FROM temp_table;
-- Insert data into temporary table (only for this session)
INSERT INTO temp_table SELECT * FROM MY_TABLE WHERE SOME_DATE IS NULL;
-- ...
END;
The only disadvantages are, in my opinion, that you got another table and that the temporary table is not dynamic.