I have an oracle error executing this PL/SQL in the second line: SELECT ....
But for God's sake ! I've already check if there is some null values
IF zocRole IS NOT NULL and devices.unit_id IS NOT NULL THEN
SELECT unit_role_id INTO unitRoleId FROM T_UNIT_ROLE WHERE role_id = zocRole AND unit_id = devices.unit_id;
END IF;
As mentioned above, this exception is thrown because your implicit cursor returns no rows. You would also get an exception if more than one row is returned.
You could instead use an Explicit Cursor Oracle Documents This is really just a named SQL statement (into which you can pass parameters if you like).
You then open the cursor, fetch (each fetch will attempt to retrieve one row) and close. You can then check whether the fetch returned any data. It takes slightly longer to code but can look cleaner.
I remember that years ago there was some debate about the relative speed of implicit vs explicit cursors but I've not heard anyone talk about this for a long time so I assume they perform the same
The best way to control the execution in a procedure/function plsql is adding blocks: BEGIN/EXCEPTION.
IF zocRole IS NOT NULL AND devices.unit_id IS NOT NULL
THEN
BEGIN
SELECT unit_role_id
INTO unitRoleId
FROM T_UNIT_ROLE
WHERE role_id = zocRole
AND unit_id = devices.unit_id
;
EXCEPTION
WHEN OTHERS
THEN dbms_output.put_line(SQLCODE||'-'||SUBSTR(SQLERRM, 1, 200));
END
;
END IF
;
Related
wondering if there is way to validate a query before executing
Is there way to check/validate Query without executing it?
One way that we validate SQL is to add a condition to the SQL that could never be true.
Example:
long ll_rc
long ll_result
string ls_sql, ls_test
string ls_message
//Arbitrary SQL
ls_sql = "SELECT * FROM DUAL"
//This SQL when executed will always return 0 if successful.
ls_test = "select count(*) from ( " + ls_sql + " WHERE 1 = 2 )"
DECLARE l_cursor DYNAMIC CURSOR FOR SQLSA ;
PREPARE SQLSA FROM :ls_test;
OPEN DYNAMIC l_cursor;
ll_rc = SQLCA.SQLCODE
choose case ll_rc
case 0
//Success
ls_message = "SQL is properly formed"
case 100
//Fetched row not found. This should not be the case since we only opened the cursor
ls_message = SQLCA.SQLERRTEXT
case -1
//Error; the statement failed. Use SQLErrText or SQLDBCode to obtain the detail.
ls_message = SQLCA.SQLERRTEXT
end choose
CLOSE l_cursor ; //This will fail if open cursor failed.
messagebox( "Result", ls_message )
Note: If your SQL is VERY complicated, which I suspect it isn't, the database optimizer may take several seconds to prepare your SQL. It will be significantly less time than if you run the entire query.
Since the database is the final arbitrator for what is "valid" (table and column names and such) the general answer is no. Now you could come up with a class in PB which checks statement syntax, object names, etc. so you wouldn't have to touch the db but it would be obsolete as soon as any changes were made to the db.
Put the select statement in any script and compile it. Part of the work will be to check the SQL syntax against the database you are connected to.
Watch out: you need at least one bound variable in the column list of your SQL statement. This is not the case for other DML statements.
Example:
in my case:
select noms into :ls_ttt from contacts;
results in a message Unknown columns 'noms' in 'field list'.
However,
select nom into :ls_ttt from contacts;
does not show any error.
Hope this helps.
I have several Oracle functions that are similar to the one below. I don't know much about Oracle and although I have made in roads on a major query re-write. I'd like to ask for some help on how to convert this function to SQL Server 2008.
I have tried using the online conversion tool at www.sqlines.com and benefited from many pages there... but not successful in converting this function....
Thanks in advance, John
Oracle source:
function OfficeIDMainPhoneID(p_ID t_OfficeID)
return t_OfficePhoneID
is
wPhID t_OfficePhoneID;
wPhID1 t_OfficePhoneID;
cursor cr_phone
is
select Office_PHONE_ID,IS_PHONE_PRIMARY
from Office_PHONE
where Office_ID = p_ID
order by SEQ_NUMBER;
begin
wPhID :=NULL;
wPhID1:=NULL;
for wp in cr_phone
loop
if wPhID is NULL
then wPhID1:=wp.Office_PHONE_ID;
end if;
if wp.IS_PHONE_PRIMARY = 'Y'
then
wPhID:=wp.Office_PHONE_ID;
Exit;
end if;
end loop;
if wPhID is NULL
then wPhID:=wPhID1;
end if;
return(wPhID);
end OfficeIDMainPhoneID;
SQL Server attempt:
create function OfficeIDMainPhoneID(#p_ID t_OfficeID)
returns t_OfficePhoneID
as
begin
declare #wPhID t_OfficePhoneID;
declare #wPhID1 t_OfficePhoneID;
declare cr_phone cursor local
for
select Office_PHONE_ID,IS_PHONE_PRIMARY
from Office_PHONE
where Office_ID = #p_ID
order by SEQ_NUMBER;
set #wPhID =NULL;
set #wPhID1=NULL;
declare wp cursor for cr_phone
open wp;
fetch wp into;
while ##fetch_status=0
begin
if #wPhID is NULL
begin set #wPhID1=wp.Office_PHONE_ID;
end
if wp.IS_PHONE_PRIMARY = 'Y'
begin
set #wPhID=wp.Office_PHONE_ID;
Exit;
end
fetch wp into;
end;
close wp;
deallocate wp;
if #wPhID is NULL
begin set #wPhID=#wPhID1;
end
return(#wPhID);
end ;
To answer the question about the functions as written
If you just want to fix the cursor so it works, one problem is the two "fetch wp into;" statements. You are saying "fetch the data and put it into" and then not giving it anything to put it into. Declare a couple of variables, put the data into them, then later use the variables, not the code. You need one variable per item returned in your cursor definition, so one each for Office_PHONE_ID and IS_PHONE_PRIMARY.
Also, you are trying to declare variables (and the function) as t_OfficePhoneID, I suspect that should be something like INT OR BIGINT instead (whatever the table definition for the column is).
Declare #OP_ID INT, #ISPRIMARY CHAR(1) --Or whatever the column is
later (in two locations),
fetch wp into (#OP_ID, #ISPRIMARY);
then use #OP_ID instead of wp.Office_PHONE_ID, and so on.
HOWEVER, I would throw away all the code in the function after declaring #wPhID, and do something else. Cursors suck if you can get what you want with a simple set based request. If you work your way through the oracle code, it is doing the following:
Get the id of the first phone number marked primary (in sequence order). If it didn't find one of those, just get the id of the first non-primary phone number in sequence order. You can do that with the following
set #wPhID = select TOP 1 Office_PHONE_ID
from Office_PHONE
where Office_ID = #p_ID
order by CASE WHEN IS_PHONE_PRIMARY = 'Y' THEN 0 ELSE 1 END, SEQ_NUMBER;
Return #wPhID and you're done.
I used "CASE WHEN IS_PHONE_PRIMARY = 'Y' THEN 0 ELSE 1 END" in the order by because I don't know what other values are possible, so this will always work. If you know the only possible values are 'Y' and 'N', you could use something like the following instead
order by IS_PHONE_PRIMARY DESC, SEQ_NUMBER;
I have the following query that I am using in Oracle 11g
IF EXISTS (SELECT * FROM EMPLOYEE_MASTER WHERE EMPID='ABCD32643')
THEN
update EMPLOYEE_MASTER set EMPID='A62352',EMPNAME='JOHN DOE',EMPTYPE='1' where EMPID='ABCD32643' ;
ELSE
insert into EMPLOYEE_MASTER(EMPID,EMPNAME,EMPTYPE) values('A62352','JOHN DOE','1') ;
END IF;
On running the statement I get the following output:
Error starting at line : 4 in command -
ELSE
Error report -
Unknown Command
1 row inserted.
Error starting at line : 6 in command -
END IF
Error report -
Unknown Command
The values get inserted with error when I run it directly. But when I try to execute this query through my application I get an oracle exception because of the error generated :
ORA-00900: invalid SQL statement
And hence the values are not inserted.
I am relatively new to Oracle. Please advise on what's wrong with the above query so that I could run this query error free.
If MERGE doesn't work for you, try the following:
begin
update EMPLOYEE_MASTER set EMPID='A62352',EMPNAME='JOHN DOE',EMPTYPE='1'
where EMPID='ABCD32643' ;
if SQL%ROWCOUNT=0 then
insert into EMPLOYEE_MASTER(EMPID,EMPNAME,EMPTYPE)
values('A62352','JOHN DOE','1') ;
end if;
end;
Here you you the update on spec, then check whether or not you found a matching row, and insert in case you didn't.
"what's wrong with the above query "
What's wrong with the query is that it is not a query (SQL). It should be a program snippet (PL/SQL) but it isn't written as PL/SQL block, framed by BEGIN and END; keywords.
But turning it into an anonymous PL/SQL block won't help. Oracle PL/SQL does not support IF EXISTS (select ... syntax.
Fortunately Oracle SQL does support MERGE statement which does the same thing as your code, with less typing.
merge into EMPLOYEE_MASTER em
using ( select 'A62352' as empid,
'JOHN DOE' as empname,
'1' as emptype
from dual ) q
on (q.empid = em.empid)
when not matched then
insert (EMPID,EMPNAME,EMPTYPE)
values (q.empid, q.empname, q.emptype)
when matched then
update
set em.empname = q.empname, em.emptype = q.emptype
/
Except that you're trying to update empid as well. That's not supported in MERGE. Why would you want to change the primary key?
"Does this query need me to add values to all columns in the table? "
The INSERT can have all the columns in the table. The UPDATE cannot change the columns used in the ON clause (usually the primary key) because that's a limitation of the way MERGE works. I think it's the same key preservation mechanism we see when updating views. Find out more.
I would like to have your advise how to implement the plsql. Below is the situation that i want to do..
select * from table A
loop - get each records from #1 step, and execute the store procedure, processMe(a.field1,a.field2,a.field3 || "test",a.field4);
i dont have any idea how to implement something like this. Below is sample parameter for processMe
processMe(
number_name IN VARCHAR,
location IN VARCHAR,
name_test IN VARCHAR,
gender IN VARCHAR )
Begin
select objId into obj_Id from tableUser where name = number_name ;
select locId into loc_Id from tableLoc where loc = location;
insert into tableOther(obj_id,loc_id,name_test,gender)
values (obj_Id ,loc_Id, name_test, gender)
End;
FOR rec IN (SELECT *
FROM table a)
LOOP
processMe( rec.field1,
rec.field2,
rec.field3 || 'test',
rec.field4 );
END LOOP;
does what you ask. You probably want to explicitly list the columns you actually want in the SELECT list rather than doing a SELECT * (particularly if there is an index on the four columns you actually want that could be used rather than doing a table scan or if there are columns you don't need that contain a large amount of data). Depending on the data volume, it would probably be more efficient if a version of processMe were defined that could accept collections rather than processing data on a row-by-row bases as well.
i just add some process. but this is just a sample. By the way, why
you said that this is not a good idea using loop? i interested to know
Performance wise, If you can avoid looping through a result set executing some other DMLs inside a loop, do it.
There is PL/SQL engine and there is SQL engine. Every time PL/SQL engine stumbles upon a SQL statement, whether it's a select, insert, or any other DML statement, it has to send it to the SQL engine for the execution. It calls context switching. Placing DML statement inside a loop will cause the switch(for each DML statement if there are more than one of them) as many times as many times the body of a loop has to be executed. It can be a cause of a serious performance degradation. if you have to loop, say, through a collection, use foreach loop, it minimizes context switching by executing DML statements in batches.
Luckily, your code can be rewritten as a single SQL statement, avoiding for loop entirely:
insert into tableOther(obj_id,loc_id,name_test,gender)
select tu.objId
, tl.locid
, concat(a.field3, 'test')
, a.field4
from table a
join tableUser tu
on (a.field1 = tu.name)
join tableLoc tl
on (tu.field2 = tl.loc)
You can put that insert statement into a procedure, if you want. PL/SQL will have to sent this SQL statement to the SQL engine anyway, but it will only be one call.
You can use a variable declared using a cursor rowtype. Something like this:
declare
cursor my_cursor is
select * from table;
reg my_cursor%rowtype;
begin
for reg in my_cursor loop
--
processMe(reg.field1, reg.field2, reg.field3 || "test", reg.field4);
--
end loop;
end;
I modified the procedure to make it smaller but I really only want to run the select query once. This will reduce the cost of running the procedure. How can I get the prevContectID and nextContentID without running the query twice. This is replacing a previous procedure so I do not want to change the IN and OUT so I do not have to find every where it is being called.
procedure getSeq(theContentID IN table.contentID%type,
prevContentID OUT table.contentID%type,
nextContentID OUT table.contentID%type)
BEGIN
SELECT myPrev into prevContentID, myNext into nextContentID
from myTable
where contentID=theContentID;
RETURN;
END getSeq;
The shown procedure most likely doesn't compile. The correct syntax for SELECT ... INTO using several variables is:
SELECT myPrev, myNext INTO prevContentID, nextContentID
from myTable
where contentID = theContentID;
You can also use a cursor to fetch the values from myTable.For your approach you need to do proper exception handling ,when theContentID does not exists in myTable,because that will give you NO_DATA_FOUND exception.
PROCEDURE getSeq (theContentID IN table.contentID%TYPE,
prevContentID OUT table.contentID%TYPE,
nextContentID OUT table.contentID%TYPE)
IS
CURSOR getcontentID_cur
IS
SELECT myPrev, myNext
FROM myTable
WHERE contentID = theContentID;
BEGIN
OPEN getcontentID_cur;
FETCH getcontentID_cur
INTO prevContentID, nextContentID;
CLOSE getcontentID_cur;
END getSeq;