Create insert record dynamically by changing pk of existing record for passed in table - oracle

I want to pass a table name and schema into a procedure, and have it generate insert, update and delete statements for the particular table. This is part of an automated testing solution (in a development environment) in which I need to test some change data capture. I want to make this dynamic as it is going to be need to be done for lots of different tables over a long period of time, and I need to call it via a REST request through ORDS, so don't want to have to make an endpoint for every table.
Update and delete are fairly easy, however I am struggling with the insert statement. Some of the tables being passed in have hundreds of columns with various constraints, fks etc. so I think it makes sense to just manipulate an existing record by changing only the primary key. I need to be able to modify the primary key to a new value known to me beforehand (e.g. '-1').
Ideally I would create a dynamic rowtype, and select into where rownum = 1, then loop round the primary keys found from all_constraints, and update the rowtype.pk with my new value, before inserting this into the table. Essentially the same as this but without knowing the table in advance.
e.g. rough idea
PROCEDURE manipulate_records(p_owner in varchar2, p_table in varchar2)
IS
cursor c_pk is
select column_name
from all_cons_columns
where owner = p_owner
and constraint_name in (select constraint_name
from all_constraints
where table_name = p_table
and constraint_type = 'P');
l_row tbl_passed_in%ROWTYPE --(I know this isn't possible but ideally)
BEGIN
-- dynamic sql or refcursor to collect a record
select * into tbl_passed_in from tablename where rownum = 1;
-- now loop through pks and reassign their values to my known value
for i in c_pk loop
...if matches then reassign;
...
end loop;
-- now insert the record into the table passed in
END manipulate_records;
I have searched around but haven't found any examples which fit this exact use case, where an unknown column needs to be modified and insert into a table.

Depending on how complex your procedure is, you might be able to store it as a template in a CLOB. Then pull it in, replace table and owner, then compile it.
DECLARE
prc_Template VARCHAR2(4000);
vc_Owner VARCHAR2(0008);
vc_Table VARCHAR2(0008);
BEGIN
vc_Table := 'DUAL';
vc_Owner := 'SYS';
-- Pull code into prc_Template from CLOB, but this demonstrates the concept
prc_Template := 'CREATE OR REPLACE PROCEDURE xyz AS r_Dual <Owner>.<Table>%ROWTYPE; BEGIN NULL; END;';
prc_Template := REPLACE(prc_Template,'<Owner>',vc_Owner);
prc_Template := REPLACE(prc_Template,'<Table>',vc_Table);
-- Create the procedure
EXECUTE IMMEDIATE prc_Template;
END;
Then you have the appropriate ROWTYPE available:
CREATE OR REPLACE PROCEDURE xyz AS r_Dual SYS.DUAL%ROWTYPE; BEGIN NULL; END;
But you can't create the procedure and run it in the same code block.

Related

Insert into not working on plsql in oracle

declare
vquery long;
cursor c1 is
select * from temp_name;
begin
for i in c1
loop
vquery :='INSERT INTO ot.temp_new(id)
select '''||i.id||''' from ot.customers';
dbms_output.put_line(i.id);
end loop;
end;
/
Output of select * from temp_name is :
ID
--------------------------------------------------------------------------------
customer_id
1 row selected.
I have customers table which has customer_id column.I want to insert all the customer_id into temp_new table but it is not being inserted. The PLSQL block executes successfully but the temp_new table is empty.
The output of dbms_output.put_line(i.id); is
customer_id
What is wrong there?
The main problem is that you generate a dynamic statement that you never execute; at some point you need to do:
execute immediate vquery;
But there are other problems. If you output the generated vquery string you'll see it contains:
INSERT INTO ot.temp_new(id)
select 'customer_id' from ot.customers
which means that for every row in customers you'll get one row in temp_new with ID set to the same fixed literal 'customer_id'. It's unlikely that's what you want; if customer_id is a column name from customers then it shouldn't be in single quotes.
As #mathguy suggested, long is not a sensible data type to use; you could use a CLOB but only really need a varchar2 here. So something more like this, where I've also switched to use an implicit cursor:
declare
l_stmt varchar2(4000);
begin
for i in (select id from temp_name)
loop
l_stmt := 'INSERT INTO temp_new(id) select '||i.id||' from customers';
dbms_output.put_line(i.id);
dbms_output.put_line(l_stmt);
execute immediate l_stmt;
end loop;
end;
/
db<>fiddle
The loop doesn't really make sense though; if your temp_name table had multiple rows with different column names, you'd try to insert the corresponding values from those columns in the customers table into multiple rows in temp_new, all in the same id column, as shown in this db<>fiddle.
I guess this is the starting point for something more complicated, but still seems a little odd.

How to use Collection as a table for UPDATE with an IN clause

I need this piece of code in a stored procedure so I can pass an array of ids and update the related records. I am wondering whether I have to use the loop rather than use an IN clause in the sp.
SET SERVEROUTPUT ON
DECLARE
P_IDS PKGINFO.t_ids; --type: table of NUMBER index by pls_integer;
P_RESULT NUMBER;
BEGIN
p_IDS(1) := 12345;
--this works fine:
for i in ( select * from table(p_ids))
loop
UPDATE TABLE1
SET FD1 = 'test'
WHERE P_ID = i.column_value;
end loop;
--this works fine too:
SELECT COUNT(*) INTO p_RESULT FROM TABLE1
WHERE P_ID IN (SELECT * FROM TABLE (p_ids));
--but this does not work, why????? how to make it work?
UPDATE TABLE1
SET FD1 = 'test'
WHERE P_ID IN (SELECT * FROM TABLE (p_ids));
END;
--==================PKGINFO.t_ids==================
CREATE OR REPLACE package dbname.PKGINFO as
-- package created to perform Associative array calls
type t_ids is table of NUMBER index by pls_integer;
end PKGINFO;
/
I expected the UPDATE can use IN clause, but it gives me an INVALID TYPE error.
Until fairly recently Oracle didn't allow PL/SQL types in SQL statements, including in a table collection expression. You seem to be using a version where support has been added for select but not (yet) for update. If you had one available then you could use a schema-level type. Also have a look at member of.
With the type you have now you could use FORALL, which would be more efficient than a loop with individual updates::
FORALL i IN p_ids.first..p_ids.last
UPDATE TABLE1
SET FD1 = 'test'
WHERE P_ID = p_ids(i);

Is there an easy to to iterate over all :NEW values from an Oracle database trigger execution?

I am attempting to write a generic trigger that will provide all of the :NEW values for the row inserted. Ultimately I want to turn them into XML and insert the XML string into a binary field on another table.
There are a variable number of columns in each table - many times over 100 fields and over 100 tables in all, so individual mapping to XML per table is extremely time consuming.
Is there a way to reference the :NEW pseudorecord as a collection of column values - or perhaps a way to pass the whole :NEW record to a Stored Procedure that could pass it to a Java function (hosted on the database) that might make the individual values iterable?
I've found an example here:
https://docs.oracle.com/database/121/LNPLS/triggers.htm
Create history table and trigger:
CREATE TABLE tbl_history ( d DATE, old_obj t, new_obj t)
/
CREATE OR REPLACE TRIGGER Tbl_Trg
AFTER UPDATE ON tbl
FOR EACH ROW
BEGIN
INSERT INTO tbl_history (d, old_obj, new_obj)
VALUES (SYSDATE, :OLD.OBJECT_VALUE, :NEW.OBJECT_VALUE);
END Tbl_Trg;
/
This seems to imply there is some sort of way it is storing all of the values as a variable, but this appears to put them directly back into a database table. I want to get the 'text' values of the column values listed.
You can create a stored procedure to create your trigger
for table tbl like
create table tbl (id number, value varchar2(10));
and an history table like
create table tbl_history (d date,id number, value varchar2(10));
you can create your trigger like this
create or replace procedure CREATE_TRIGGER IS
trig_str VARCHAR2(32767);
col_str VARCHAR2(32767) := '(d';
values_str VARCHAR2(32767) := '(sysdate';
begin
trig_str := 'CREATE OR REPLACE TRIGGER Tbl_Trg AFTER UPDATE ON tbl FOR EACH ROW'||chr(10)||
'BEGIN'||chr(10)||chr(9)||'INSERT INTO tbl_history ';
for col in (
SELECT column_name FROM all_tab_columns where table_name = 'TBL'
) loop
col_str := col_str||','||col.column_name;
values_str := values_str||','||':OLD.'||col.column_name;
end loop;
col_str := substr(col_str,1,length(col_str)-1)||')';
values_str := substr(values_str,1,length(values_str)-1)||')';
trig_str := trig_str||col_str||' VALUES '||values_str||';'||chr(10)||'END;';
execute immediate trig_str;
END;
/
With an history table with old and new values it's a bit more complicated but same idea

PL/SQL Creating a procedure that contains result set joins

I want to create a procedure in PL/SQL that has 5 steps. Step 1 and 2 execute first and return an ID. In step 3, we have a SELECT statement that has a condition with that returned ID. I want then to take all of the results of that SELECT statement and use them in a JOIN in another SELECT statement and use THOSE results in a 3rd SELECT statement again using JOIN. From what I've seen, I can't use CURSOR in JOIN statements. Some of my co-workers have suggested that I save the results in a CURSOR and then use a loop to iterate through each row and use that data for the next SELECT. However since I'm going to do 2 selects this will create a huge fork of inside loops and that's exactly what I'm trying to avoid.
Another suggestion was to use Temprary Tables to store the data. However this procedure could be executed at the same time by many users and the table's data would conflict with each other. Right now I'm looking at LOCAL Temporary tables that supposedly filter the data according the the session but I'm not really sure I want to create dummy tables for my procedures since I want to avoid leaving trash in the schema (this procedure is for a custom part of the application). Is there a standard way of doing this? Any ideas?
Sample:
DECLARE
USERID INT := 1000000;
TEXT1 VARCHAR(100);
TEXT_INDEX INT;
CURSOR NODES IS SELECT * FROM NODE_TABLE WHERE DESCRIPTION LIKE TEXT || '%';
CURSOR USERS IS SELECT * FROM USERGROUPS JOIN NODES ON NODES.ID = USERGROUPS.ID;
BEGIN
SELECT TEXT INTO TEXT1 FROM TABLE_1 WHERE ID = USERID;
TEXT_INDEX = INSTR(TEXT, '-');
TEXT = SUBSTR(TEXT, 0, TEXT_INDEX);
OPEN NODES;
OPEN USERS;
END;
NOTE: This does NOT work. Oracle doesn't support joins between cursors.
NOTE2: This CAN be done in a single query but for the sake of argument (and in my real use case) I want to break those steps down in a procedure. The sample code is a depiction of what I'm trying to achieve IF joins between cursors worked. But they don't and I'm looking for an alternative.
I ended up using a function (although a procedure could be used as well) along with tables. Things I've learned and one should pay attention to:
PL/SQL functions can only return types that have been declared in the schema in advance and are clear. You can't create a function that returns something like MY_TABLE%ROWTYPE, even though it seems the type information is available it is not acceptable. You have to instead create a custom type of MY_TABLE%ROWTYPE is you want to return it.
Oracle treats tables of declared types differently from tables of %ROWTYPE. This confused the hell out of me at first but from what I've gathered this is how it works.
DECLARE TYPE MY_CUSTOM_TABLE IS TABLE OF MY_TABLE%ROWTYPE;
Declares a collection of types of MY_TABLE row. In order to add to this we must use BULK COLLECT INTO from an SQL statement that queries MY_TABLE. The resulting collection CANNOT be used in JOIN statements is not queryable and CANNOT be returned by a function.
DECLARE
CREATE TYPE MY_CUSTOM_TYPE AS OBJECT (COL_A NUMBER, COL_B NUMBER);
CREATE TYPE MY_CUSTOM_TABLE AS TABLE OF MY_CUSTOM_TYPE;
my_custom_tab MY_CUSTOM_TABLE;
This create my_custom_tab which is a table (not a collection) and if populated can be queried at using TABLE(my_custmo_tab) in the FROM statement. As a table which is declared in advance in the schema this CAN be returned from a function. However it CANNOT be populated using BULK COLLECT INTO since it is not a collection. We must instead use the normal SELECT INTO statement. However, if we want to populate it with data from an existing table that has 2 number columns we cannot simply do SELECT * INTO my_custom_tab FROM DOUBLE_NUMBER_TABLE since my_custom_tab hasn't been initialized and doesn't contain enough rows to receive the data. And if we don't know how many rows a query returns we can't initialize it. The trick into populating the table is to use the CAST command and cast our select result set as a MY_CUSTOM_TABLE and THEN add it.
SELECT CAST(MULTISET(SELECT COL_A, COL_B FROM DOUBLE_NUMBER_TABLE) AS MY_CUSTOM_TABLE) INTO my_custom_tab FROM DUAL
Now we can easily use my_custom_tab in queries etc through the use of the TABLE() function.
SELECT * FROM TABLE(my_custom_tab)
is valid.
You can do such decomposition in many ways, but all of them have a significant performance penalty in comaration with single SQL statement.
Maintainability improvement are also questionable and depends on specific situation.
To review all possibilities please look through documentation.
Below is some possible variants based on simple logic:
calculate Oracle user name prefix based on given Id;
get all users whose name starts with this prefix;
find all tables owned by users from step 2;
count a total number of found tables.
1. pipelined
Prepare types to be used by functions:
create or replace type TUserRow as object (
username varchar2(30),
user_id number,
created date
)
/
create or replace type TTableRow as object (
owner varchar2(30),
table_name varchar2(30),
status varchar2(8),
logging varchar2(3)
-- some other useful fields here
)
/
create or replace type TUserList as table of TUserRow
/
create or replace type TTableList as table of TTableRow
/
Simple function to find prefix by user id:
create or replace function GetUserPrefix(piUserId in number) return varchar2
is
vUserPrefix varchar2(30);
begin
select substr(username,1,3) into vUserPrefix
from all_users
where user_id = piUserId;
return vUserPrefix;
end;
/
Function searching for users:
create or replace function GetUsersPipe(
piNameStart in varchar2
)
return TUserList pipelined
as
vUserList TUserList;
begin
for cUsers in (
select *
from
all_users
where
username like piNameStart||'%'
)
loop
pipe row( TUserRow(cUsers.username, cUsers.user_id, cUsers.created) ) ;
end loop;
return;
end;
Function searching for tables:
create or replace function GetUserTablesPipe(
piUserNameStart in varchar2
)
return TTableList pipelined
as
vTableList TTableList;
begin
for cTables in (
select *
from
all_tables tab_list,
table(GetUsersPipe(piUserNameStart)) user_list
where
tab_list.owner = user_list.username
)
loop
pipe row ( TTableRow(cTables.owner, cTables.table_name, cTables.status, cTables.logging) );
end loop;
return;
end;
Usage in code:
declare
vUserId number := 5;
vTableCount number;
begin
select count(1) into vTableCount
from table(GetUserTablesPipe(GetUserPrefix(vUserId)));
dbms_output.put_line('Users with name started with "'||GetUserPrefix(vUserId)||'" owns '||vTableCount||' tables');
end;
2. Simple table functions
This solution use same types as a variant with pipelined functions above.
Function searching for users:
create or replace function GetUsers(piNameStart in varchar2) return TUserList
as
vUserList TUserList;
begin
select TUserRow(username, user_id, created)
bulk collect into vUserList
from
all_users
where
username like piNameStart||'%'
;
return vUserList;
end;
/
Function searching for tables:
create or replace function GetUserTables(piUserNameStart in varchar2) return TTableList
as
vTableList TTableList;
begin
select TTableRow(owner, table_name, status, logging)
bulk collect into vTableList
from
all_tables tab_list,
table(GetUsers(piUserNameStart)) user_list
where
tab_list.owner = user_list.username
;
return vTableList;
end;
/
Usage in code:
declare
vUserId number := 5;
vTableCount number;
begin
select count(1) into vTableCount
from table(GetUserTables(GetUserPrefix(vUserId)));
dbms_output.put_line('Users with name started with "'||GetUserPrefix(vUserId)||'" owns '||vTableCount||' tables');
end;
3. cursor - xml - cursor
It's is a specific case, which may be implemented without user-defined types but have a big performance penalty, involves unneeded type conversion and have a low maintainability.
Function searching for users:
create or replace function GetUsersRef(
piNameStart in varchar2
)
return sys_refcursor
as
cUserList sys_refcursor;
begin
open cUserList for
select * from all_users
where username like piNameStart||'%'
;
return cUserList;
end;
Function searching for tables:
create or replace function GetUserTablesRef(
piUserNameStart in varchar2
)
return sys_refcursor
as
cTableList sys_refcursor;
begin
open cTableList for
select
tab_list.*
from
(
XMLTable('/ROWSET/ROW'
passing xmltype(GetUsersRef(piUserNameStart))
columns
username varchar2(30) path '/ROW/USERNAME'
)
) user_list,
all_tables tab_list
where
tab_list.owner = user_list.username
;
return cTableList;
end;
Usage in code:
declare
vUserId number := 5;
vTableCount number;
begin
select count(1) into vTableCount
from
XMLTable('/ROWSET/ROW'
passing xmltype(GetUserTablesRef(GetUserPrefix(vUserId)))
columns
table_name varchar2(30) path '/ROW/TABLE_NAME'
)
;
dbms_output.put_line('Users with name started with "'||GetUserPrefix(vUserId)||'" owns '||vTableCount||' tables');
end;
Of course, all variants may be mixed, but SQL looks better at least for simple cases:
declare
vUserId number := 5;
vUserPrefix varchar2(100);
vTableCount number;
begin
-- Construct prefix from Id
select max(substr(user_list.username,1,3))
into vUserPrefix
from
all_users user_list
where
user_list.user_id = vUserId
;
-- Count number of tables owned by users with name started with vUserPrefix string
select
count(1) into vTableCount
from
all_users user_list,
all_tables table_list
where
user_list.username like vUserPrefix||'%'
and
table_list.owner = user_list.username
;
dbms_output.put_line('Users with name started with "'||vUserPrefix||'" owns '||vTableCount||' tables');
end;
P.S. All code only for demonstration purposes: no optimizations and so on.

Simple oracle insert

I am trying to simply insert some information to a table in Oracle using Forms. Sometimes the insert statement works, sometimes it doesn't. I'm just not experienced enough with Oracle to understand what's not working. Here's the code:
PROCEDURE create_account IS
temp_name varchar2(30);
temp_street varchar2(30);
temp_zip number(5);
temp_phone varchar2(30);
temp_login passuse.login%type;
temp_pass varchar2(30);
temp_total number(4);
temp_lgn passuse.lgn%type;
cursor num_cursor is
select MAX(ano)
from accounts;
cursor lgn_cursor is
select MAX(lgn)
from passuse;
BEGIN
temp_name:= Get_Item_Property('ACCOUNTS.A_NAME', database_value);
temp_street:= Get_Item_Property('ACCOUNTS.STREET', database_value);
temp_zip:= Get_Item_Property('ACCOUNTS.ZIP', database_value);
temp_phone:= Get_Item_Property('ACCOUNTS.STREET', database_value);
temp_login:= Get_Item_Property('PASSUSE.LOGIN', database_value);
temp_pass:= Get_Item_Property('PASSUSE.PASS', database_value);
open num_cursor;
fetch num_cursor into temp_total;
open lgn_cursor;
fetch lgn_cursor into temp_lgn;
if(lgn_cursor%found) then
if(num_cursor%found) then
temp_lgn := temp_lgn + 20;
--the trouble maker..
INSERT INTO passuse (lgn, a_type, login, pass)
VALUES (temp_lgn, 1, temp_login, temp_pass);
temp_total := temp_total+1;
INSERT INTO accounts(ano,lgn,a_name,street,zip,phone)
VALUES (temp_total,temp_lgn,temp_name,temp_street,temp_zip,temp_phone);
end if;
end if;
close lgn_cursor;
close num_cursor;
commit;
END;
To expand on #Mikpa's comment - it certainly appears that getting the values for ACCOUNTS.ANO and PASSUSE.LGN from sequences would be a good idea. Populating these fields automatically by using a trigger would also be helpful. Something like the following:
-- Note that the following is intended as a demo. When executing these statements
-- you'll probably have to modify them for your particular circumstances.
SELECT MAX(ANO) INTO nMax_ano FROM ACCOUNTS;
SELECT MAX(LGN) INTO nMax_lgn FROM PASSUSE;
CREATE SEQUENCE ACCOUNTS_SEQ START WITH nMax_ano+1;
CREATE SEQUENCE PASSUSE_SEQ START WITH nMax_lgn+1;
CREATE TRIGGER ACCOUNTS_BI
BEFORE INSERT ON ACCOUNTS
FOR EACH ROW
BEGIN
SELECT ACCOUNTS_SEQ.NEXTVAL
INTO :NEW.ANO
FROM DUAL;
END ACCOUNTS_BI;
CREATE TRIGGER PASSUSE_BI
BEFORE INSERT ON PASSUSE
FOR EACH ROW
BEGIN
SELECT PASSUSE_SEQ.NEXTVAL
INTO :NEW.LGN
FROM DUAL;
END PASSUSE_BI;
Having done the above you can now write your inserts into these tables as
INSERT INTO passuse (a_type, login, pass)
VALUES (1, temp_login, temp_pass)
RETURNING LGN INTO temp_lgn;
and
INSERT INTO accounts(lgn, a_name, street, zip, phone)
VALUES (temp_lgn, temp_name, temp_street, temp_zip, temp_phone);
Note that in the both statements the key values (PASSUSE.LGN and ACCOUNTS.ANO) are not mentioned in the field list as the new triggers should take care of filling them in correctly. Also note that when inserting into PASSUSE the RETURNING clause is used to get back the new value for LGN so it can be used in the insert into the ACCOUNTS table.
Share and enjoy.

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