I am trying to use the PL/SQL accept functionality to take in user input. However I want the user input to be able to accept single and or double quotes. The double quotes don't seem to be a problem, however the single quote is a problem. I have my code posted below, but I keep getting errors because it doesn't like the single quote. While I know in a practical situation, the user input would be taken in via a web front end and passed to the database, unfortunately this homework assignment is asking for PL/SQL only. Any help is greatly appreciated, thanks!
Accept p_1 prompt 'Please enter the region name (CHILD_NAME):'
DECLARE
--pragma execption_init
user_input REGION.CHILD_NAME%type := '&p_1';
v_res number :=0;
BEGIN
SYS.DBMS_OUTPUT.PUT_LINE('USER INPUT:');
SYS.DBMS_OUTPUT.PUT_LINE(user_input);
SYS.DBMS_OUTPUT.PUT_LINE('');
SYS.DBMS_OUTPUT.PUT_LINE('MY OUTPUT:');
/* select count(*)
into v_res
from REGION where upper(CHILD_NAME) like upper(user_input);
if v_res = 0 then
SYS.DBMS_OUTPUT.PUT_LINE(user_input ||' is not in the table.');
else
SYS.DBMS_OUTPUT.PUT_LINE('Need to build my logic here.');
end if;
SYS.DBMS_OUTPUT.PUT_LINE('');*/
END;
Use alternative quoting mechanism q:
set serveroutput on
accept p_1 prompt 'Say something: '
declare
v_something varchar2(32767) := q'[&p_1]';
begin
dbms_output.put_line('(v_something = ' || v_something || ')');
end;
/
Example run
SQL> #so52
Say something: 'foo [is] 'bar''
old 2: v_something varchar2(32767) := q'[&p_1]';
new 2: v_something varchar2(32767) := q'['foo [is] 'bar'']';
(v_something = 'foo [is] 'bar'')
PL/SQL procedure successfully completed.
SQL>
Related
I have written following code in oracle pl/sql
create or replace procedure sorting_criteria(criteria in varchar)
as
begin
if(criteria='lowest price')
then
declare
p_name product.p_name%type;
cursor ptr is select p_name from product order by amount ASC;
begin
open ptr;
loop
fetch ptr into p_name;
exit when ptr%notfound;
dbms_output.put_line(p_name);
end loop;
close ptr;
end;
else if(criteria='highest price')
then
declare
p_name product.p_name%type;
cursor ptr is select p_name from product order by amount DESC;
begin
open ptr;
loop
fetch ptr into p_name;
exit when ptr%notfound;
dbms_output.put_line(p_name);
end loop;
close ptr;
end;
else
dbms_output.put_line('Enter valid criteria!');
end if;
end;
/
But it is giving following error: Error at line 35: PLS-00103: Encountered the symbol ";" when expecting one of the following: Please help
The ELSE-IF statement in PL/SQL has to be written as ELSIF. Otherwise, you should close the second IF with an other END IF; statement.
You can solve the issue by changing the ELSE IF at line 17 to an ELSIF
The answer by #GregorioPalamà correctly addresses your issues. But you can drastically reduce the workload by changing your thinking away from "If...then...else" to the "set of" and letting SQL do the work. In this case the only difference is sorting either ascending or descending on amount. The same effect can be achieved by sorting ascending on amount or minus amount; and SQL can make that decision. So you can reduce the procedure to validating the parameter and a single cursor for loop:
create or replace procedure sorting_criteria(criteria in varchar2)
as
cursor ptr(c_sort_criteria varchar2) is
select p_name
from product
order by case when c_sort_criteria = 'lowest price'
then amount
else -amount
end ;
begin
if criteria in ('lowest price', 'highest price')
then
for rec in ptr(criteria)
loop
dbms_output.put_line('Product: ' || rec.p_name );
end loop;
else
dbms_output.put_line('Enter valid criteria!');
end if;
end sorting_criteria;
/
See demo here. For demonstration purposed I added the amount to the dbms_output.
A couple notes:
While it is not incorrect using p_... as a column name, it is also
not a good idea. A very common convention (perhaps almost a
standard) to use p_... to indicate parameters. This easily leads to
confusion; confusion amongst developers is a bad thing.
IMHO it is a bug to name a local variable the same as a table
column name. While the compiler has scoping rules which one to use
it again leads to confusion. The statement "where table.name = name"
is always true, except when at least one of them is null, which possible could lead to updating/deleting every row in your table. In this
case p_name is both a column and a local variable.
I am trying this but sure I am missing a lot
declare
my_id table.ISR_ID%type;
begin
select NVL(MAX(table.ISR_ID)+1,1) into isr_id
from table;
select my_pkg.getFunction(InputToFunction=> isr_id); -- from ?
end;
If you declared MY_ID variable, you should have selected into it, not into ISR_ID (which is never declared).
Also, you should return function's result into something (probably another variable?). I've declared it as FUN_RES - see the comment within the PL/SQL anonymous block.
Saying that you are missing a lot doesn't help much; you should specify which errors you get. Anyway: try such a code, say whether it works or not and - if not - say why not (possible errors, etc.).
declare
my_id table.ISR_ID%type;
fun_res number; --> function result should be returned into this variable.
-- I don't know what it returns, so I set it to be a NUMBER.
-- Change it, if necessary.
begin
select NVL(MAX(table.ISR_ID) + 1, 1)
into my_id
from table;
fun_res := my_pkg.getFunction(my_id);
end;
[EDIT]
If you have to select function's value for every ISR_ID in a table, then you don't need PL/SQL but
select isr_id,
my_pkg.getfunction(isr_id) fun_res
from table;
If you want PL/SQL, then do it in a loop, for example:
begin
for cur_r in (select isr_id from table) loop
dbms_output.put_line(cur_r.isr_id ||', result = ' || my_pkg.getfunction(cur_r.isr_id));
end loop;
end;
/
I have the following code:
declare
y pls_integer := 0;
v_msg varchar2(4000);
plsql varchar(4000);
begin
if not apex_collection.collection_exists(p_collection_name=>'P16_COLLECTION') then
wwv_flow.debug('No Apex collection found!');
else
for x in (select * from apex_collections where collection_name = 'P16_COLLECTION' and seq_id > 1 order by seq_id)
loop
y := y+1;
FOR i IN 1..25
LOOP
plsql := 'begin apex_collection.update_member_attribute (p_collection_name=> ''P16_COLLECTION'', p_seq=>' || TO_CHAR(x.seq_id) || ',p_attr_number =>' || TO_CHAR(i) || ',p_attr_value=>wwv_flow.g_f' || TO_CHAR(i, 'FM00') || '(' || TO_CHAR(y) || ')); end;';
wwv_flow.debug(plsql);
EXECUTE IMMEDIATE plsql;
END LOOP;
end loop;
end if;
exception when others then
v_msg := ''||sqlerrm;
wwv_flow.debug('ERR: '||v_msg);
end;
This code is very similar to the one proposed here, but I loop through 25 columns. The issue with Oracle Apex is the max number of chars PL/SQL is allowed to have, so I am unable to just write 25 update_member_attribute - calls.
But instead of a it excecuting I get an error no data found.
I triple checked that the collection P16_COLLECTION exists.
The issue with Oracle Apex is the max number of chars PL/SQL is allowed to have
I'm not sure I understood this statement. It is PL/SQL you use. You declared a local PLSQL variable as VARCHAR2(4000). Why didn't you specify its max allowed size, 32767? Would that help?
Furthermore, saying that you got NO-DATA-FOUND exception: are you sure that this piece of code raised it? Because, there's no SELECT statement in there ... the one you used in a cursor FOR loop can't raise NO-DATA-FOUND; UPDATE either. Therefore, it must be something else, I presume.
Enable DEBUG, run the page and - when you get the error - view debug results and locate the culprit.
I need to run some SQL blocks to test them, is there an online app where I can insert the code and see what outcome it triggers?
Thanks a lot!
More specific question below:
<<block1>>
DECLARE
var NUMBER;
BEGIN
var := 3;
DBMS_OUTPUT.PUT_LINE(var);
<<block2>>
DECLARE
var NUMBER;
BEGIN
var := 200;
DBMS_OUTPUT.PUT_LINE(block1.var);
END block2;
DBMS_OUTPUT.PUT_LINE(var);
END block1;
Is the output:
3
3
200
or is it:
3
3
3
I read that the variable's value is the value received in the most recent block so is the second answer the good one? I'd love to test these online somewhere if there is a possibility.
Also, is <<block2>> really the correct way to name a block??
Later edit:
I tried this with SQL Fiddle, but I get a "Please build schema" error message:
Thank you very much, Dave! Any idea why this happens?
create table log_table
( message varchar2(200)
)
<<block1>>
DECLARE
var NUMBER;
BEGIN
var := 3;
insert into log_table(message) values (var)
select * from log_table
<<block2>>
DECLARE
var NUMBER;
BEGIN
var := 200;
insert into log_table(message) values (block1.var || ' 2nd')
select * from log_table
END block2;
insert into log_table(message) values (var || ' 3rd')
select * from log_table
END block1;
In answer to your three questions.
You can use SQL Fiddle with Oracle 11g R2: http://www.sqlfiddle.com/#!4. However, this does not allow you to use dbms_output. You will have to insert into / select from tables to see the results of your PL/SQL scripts.
The answer is 3 3 3. Once the inner block is END-ed the variables no longer exist/have scope. You cannot access them any further.
The block naming is correct, however, you aren't required to name blocks, they can be completely anonymous.
EDIT:
So after playing with SQL Fiddle a bit, it seems like it doesn't actually support named blocks (although I have an actual Oracle database to confirm what I said earlier).
You can, however, basically demonstrate the way variable scope works using stored procedures and inner procedures (which are incidentally two very important PL/SQL features).
Before I get to that, I noticed three issues with you code:
You need to terminate the insert statements with a semi-colon.
You need to commit the the transactions after the third insert.
In PL/SQL you can't simply do a select statement and get a result, you need to select into some variable. This would be a simple change, but because we can't use dbms_output to view the variable it doesn't help us. Instead do the inserts, then commit and afterwards select from the table.
In the left hand pane of SQL Fiddle set the query terminator to '//' then paste in the below and 'build schema':
create table log_table
( message varchar2(200)
)
//
create or replace procedure proc1 as
var NUMBER;
procedure proc2 as
var number;
begin
var := 200;
insert into log_table(message) values (proc1.var || ' 2nd');
end;
begin
var := 3;
insert into log_table(message) values (var || ' 1st');
proc2;
insert into log_table(message) values (var || ' 3rd');
commit;
end;
//
begin
proc1;
end;
//
Then in the right hand panel run this SQL:
select * from log_table
You can see that proc2.var has no scope outside of proc2. Furthermore, if you were to explicitly try to utilize proc2.var outside of proc2 you would raise an exception because it is out-of-scope.
I want to assign a value to a rowtype's field but I don't know how to do it.
Suppose that I have a table X inside my database.
Suppose also that I have the following variables
a ( X%ROWTYPE ), representing a row of the table X
b ( VARCHAR2 ), containing a column name of the table X
c ( VARCHAR2 ), containing what I want to store inside a.b
What I want to do : something like a.b := c.
I've come up with something like this :
EXECUTE IMMEDIATE 'SELECT '|| c || ' INTO a.' || b || ' FROM DUAL';
Apparently, this isn't the right way to go. I get a ORA-0095: missing keyword error.
Can anyone help me with this ?
Here is the complete code :
DECLARE
tRow MyTable%ROWTYPE;
col_name VARCHAR(10) := 'Length';
nValue NUMBER(12,4) := 0.001;
dynamic_request VARCHAR(300);
BEGIN
dynamic_request := 'SELECT '|| nValue || ' INTO tRow.' || col_name || ' FROM DUAL';
EXECUTE IMMEDIATE dynamic_request;
END;
Ok, I solved it !
Short answer : Using a global variable does the trick
Answer Development
Let us consider two facts about dynamic PL/SQL blocks (i.e., PL/SQL blocks written as strings, to be executed trough an EXECUTE IMMEDIATE statement)
[1] There is no such thing as variable scope when you create a dynamic PLSQL block. What I mean by that is, if you do something like this :
CREATE OR REPLACE PROCEDURE DynamicVariableAssignment(
theString IN VARCHAR2
)
IS
BEGIN
EXECUTE IMMEDIATE 'BEGIN theString := ''test''; END; ';
END;
it will simply not work because the scope of theString is not transfered to the dynamic PL/SQL block. In other words, the dynamic PL/SQL block doesn't "inherit" of any variable, wherever it is executed.
[2] You might say "OK, no panic, I can give input/output arguments to my dynamic PL/SQL block, right ?". Sure you can, but guess what : you can only give SQL types as in/out ! True PL/SQL types on the other hand, such as a myTable%rowtype, are not accepted as an input for a dynamic PL/SQL block. So the answer of hmmftg won't work either :
-- I've reduced the code to the interesting part
dynamic_request := 'BEGIN :t_row.' || col_name || ':= 0.001; END;';
EXECUTE IMMEDIATE dynamic_request USING IN OUT tRow;
-- (where tRow is of type myTable%ROWTYPE)
since tRow is of MyTable%ROWTYPE, it is not a valid SQL type and is therefore not valid as an input to the dynamic PL/SQL block.
The Solution Who would have thought that global variables would come and save the day ? As we said in [1], we have no reference to any variable outside the dynamic PL/SQL block. BUT we can still access global variables defined in package headers !
Let us assume that I have a package kingPackage in which I define the following :
tempVariable myTable%ROWTYPE;
Then I can do this :
FINAL CODE (body only)
-- Copy tRow into temp variable
kingPackage.tempVariable := tRow;
-- We modify the column of the temp variable
vString := 'BEGIN kingPackage.tempVariable.' || col_val || ' := ' || TO_CHAR(vNumber) ||'; END;';
EXECUTE IMMEDIATE vString;
-- The column value has been updated \o/
tRow := kingPackage.tempVariable;
There you go, fellas !
Have a nice day
try this:
CREATE OR REPLACE PROCEDURE ROW_CHANGER(
tRow IN MyTable%ROWTYPE,
col_name IN VARCHAR,
nValue IN NUMBER)
AS
dynamic_request VARCHAR(300);
BEGIN
dynamic_request := 'BEGIN :t_row.'||COL_NAME ||':= :n_value; END;';
EXECUTE IMMEDIATE dynamic_request
USING IN OUT TROW, IN nValue;
END;
this is because in your EXECUTE IMMEDIATE the tRow MyTable%ROWTYPE is not defined,
so we defined it with using statement.