I am trying to count with condition in VFP.I am not trying to select anything, so I don't think I could use count here(correct me if i am wrong).
I used reccount() to count number of rows in my table, but I need to add a condition with reccount(),
for example, I want to count rows with condition itemid=counter1, where itemid has repeated numbers in it, but counter1 is a counter I set up initially. So I want to count how many itemid=1 there are, and so on.
Would my statement be similar to
RECCOUNT() where itemid=counter1
In manual of VFP, it seems like reccount cannot go with any conditions. I couldn't find any other ways to count with condition without the select command. Could anyone give some suggestions?
Use the "Count" keyword and the "For" clause... You can reference field(s) in the cursor in the For condition. Like this:
Select MyCursor
Count to m.count For FieldValue = 1 and Blah = .t.
Note this will move the record point in the cursor to the end, so you will need to store the Recno() and use Locate to restore it to the location it was at, if needed.
You can also use a Select statement and determine the count by referencing the special value _Tally that VFP uses after certain data row functions. Like this:
Select * from MyCursor Where FieldValue = 1 and Blah = .t. Into Array laCount
lnCount = _Tally
The cool thing about this approach is that it does not move the record pointer in the cursor.
Related
SET STEP ON
Close Databases
Cd e:\ksv\Data
Use ohd IN 0 shared
Use cus IN 0 shared
SELECT * FROM cus inTO TABLE tempcus
ALTER table tempcus ADD COLUMN totalsold int
UPDATE tempcus SET totalsold=RECCOUNT(ohd.status='5') WHERE tempcus.customer=ohd.customer
SELECT * FROM tempcus INTO CURSOR cur
BROWSE
I have tried the above code and i am getting an error saying invalid table number , can someone help me with this.
RECCOUNT() function only gives you a record count for a workarea# or alias, e.g. RECCOUNT("ohd") will give total record count of ohd table.
You want something like:
SELECT COUNT(*) totalsold,cus.customer FROM cus JOIN ohd ON cus.customer=ohd.customer WHERE ohd.cstatus='5' INTO CURSOR cur GROUP BY cus.customer
BROWSE
In VFP, there is a REPLACE command which allows you to replace one or more fields based on whatever values, even if variable results from other queries... or fixed values. Ex: This works on whatever table is the current selected work area and whatever row it is on, unless you apply a scope clause (for condition).
Sample only for context of REPLACE command
use SomeOtherTable in 0 shared
select SomeOtherTable
replace SomeNumberField with 1.234, SomeStringField with 'Hello', etc...
or with condition (bogus, just to show you can apply to multiple rows.
replace SomeNumberField with SomeNumberField * 3 for StatusField = 'X'
Now, back to your original content. It appears you are trying to get a result temporary table with a total number of records from the OHD table where the status = 5. VFP allows you to run SQL-Select into temporary read-write "cursor" tables, that when closed will delete themselves, yet allows them to be modified (such as browse, or other direct manipulation such as with REPLACE command).
You can get the counts you are looking for with a left-join to a query result set. To help you see the pieces individually, I will do in steps so you can follow, then join into one final.
First, you want a count of all records in the OHD table with status = 5 per customer... the "o" and "c" are ALIAS references in the SQL queries below
SET STEP ON
Close Databases
Cd e:\ksv\Data
Use ohd IN 0 shared
Use cus IN 0 shared
select ;
o.customer, ;
count(*) NumberOfRecords ;
from ;
OHD o ;
where ;
o.status = '5' ;
group by ;
o.customer ;
into ;
cursor C_JustCountsPerCustomer READWRITE
The "into cursor" part above will create a workable table and give it the name of "C_JustCountsPerCustomer". I have always tried to use "C_" as a prefix to the table name for the sole purpose to know it is a temporary "CURSOR" result and not a real final table, but that is just my historical naming convention applied.
Now, if you did a browse of this result, you would see each customer's ID and how many with status = '5'. The resulting table "cursor" is like any other table opened and you could index as you need and browse, etc. But this only will give records that HAD status of '5'. But you could have more customers that never had a '5' status record.
Now, getting all your customers and their respective counts into one result table "cursor". I can take the above query and use within a SQL-Select via a LEFT-JOIN meaning, give me everything from the first table (left-side), regardless of a matching record found in the second table (right-side). But if there is a match to the right side, give me those values too.
select ;
c.*, ;
NVL( C_tmpResult.NumberOfRecords, 0000 ) as NumberOfRecords ;
from;
CUS c ;
LEFT JOIN ;
(select ;
o.customer, ;
count(*) NumberOfRecords ;
from ;
OHD o ;
where ;
o.status = '5' ;
group by ;
o.customer ) C_tmpResult ;
ON ;
c.customer = C_tmpResult.customer ;
into ;
cursor C_CusWithCounts readwrite
So, you can see the left-join uses the first query to get the counts, but the primary part of the query gets records from the customer table (alias "c") and is joined on the common customer id column. The "NVL()" states if there IS a value in the C_tmpResult table for the given customer, grab that. If not, assume a count of 0. Yes, I explicitly have 0000 to force a minimum final width to 4 digits in the result in case the first customer does not have any and it make the column only 1 digit wide.
Anyhow, at the end, you would have your result temporary table (cursor) with the customer information AND the count I think you are looking for. You should be able to do a browse and good to go.
I'm new in PL/SQL. I have a matrix stored in the DB as a nested table. Something like,
the matrix is stored as a TABLE of objects (and objects are t1 number, t2 number, ... t100 number)
To to get the matrix it would be select x.* from test t, table(t.matrix) x where... , returning
|T1|T2|T3|...|T100|
I want to create a function that returns the sum over the row to be called using SQL only, something equivalent to
select sum(x.T1),sum(x.T2)...sum(x.T100) from test t, table(t.matrix) x where ...
Something like select bigsum(x.*) from table t, table(t.matrix)
It will be called several times, and I don't want to write the 100 columns every time.
If you want to sum the values from 100 different columns, you're going to have to explicitly list those 100 columns at some point. You can encapsulate that logic for that expression in a view or a function or a pipelined table function or some other construct so that you don't have to repeat the expression many times, you just have to reference the abstraction you've created (i.e. call the function that sums the 100 values).
Although it would likely complicate the problem rather than simplifying it, you could potentially create a solution that uses dynamic SQL to generate the 100 columns names and the expression to add them together if you really, really want to avoid writing out 100 column names. It is highly unlikely, however, that the extra complexity of resorting to dynamic SQL would be beneficial unless there are substantial requirements that you haven't mentioned here that make writing out the column names more than a bit repetitive.
" it'll be called several times, and don't want to write the 100
columns every time"
Why not create a view? Write it once, call it as many times as you like:
create or replace view bigsum
select t.whatever
, sum(x.T1) as sum_t1
, sum(x.T2) as sum_t2
...
, sum(x.T100) as sum_t100
from test t
, table(t.matrix) x
group by t.whatever
You would need to include identifying columns from TEST to allow you to join the view to other tables. This approach would give you something close to want you want:
select *
from bigsum
where whatever = 23
You can reduce the amount of typing further by processing a result set from the data dictionary view USER_TYPE_ATTRS (or a SQL*Plus description) in a decent text editor with a regex search'n'replace.
you can create a function in the below given form depending on your condition and if you require parameter then you can add them while creating function and use them in the condition required
create or replace function bigsum
return number
as
sumall number;
begin
select (sum(x.T1),sum(x.T2)...sum(x.T100)) into sumall
from test t, table(t.matrix) x where .(your condition).. ;
return sumall;
end;/
and call it in the manner
select bigsum from dual;
I'm here because i could not finde anywhere else if there is a way to return the previous value in a loop (Cursor) to compare with the current value, for instance..
Cursor.Value = Cursor-1.Value;
It's bacause i have several contract numbers that i need to send by mail to the Business sector, but, in order to resume all the rows i want to compare if the current contract number are the same as the last contract number and validate it to dont send duplicated contract numbers.
Exemple of Record that i to skip in order to send no duplicate "Order Numbers": (Order_Number is my Key, not a sequencial numeric id):
cCursor.Value = cCursor-1.Value
cCursor.(111) = cCursor-1.(111)
Exemple of Record that i want to save in order to send as a processed "Order Number": (Order_Number is my Key, not a sequencial numeric id):
cCursor.Value = cCursor-1.Value
cCursor.(132) = cCursor-1.(111)
My Regards.
You cant reference backwards. Th easiest alternative is to store the key value (contract_id) in a variable and have logic like:
DECLARE
CURSOR c1 IS .....;
vLastContractID NUMBER := 0;
BEGIN
FOR r1 IN c1 LOOP
IF vLastContractID != r1.CONTRACT_ID THEN
-- do something
vLastContractID := r1.CONTRACT_ID;
END IF;
END LOOP;
END;
It's not entirely clear what you are asking.
A cursor is a forward-only structure. You cannot fetch a prior row, just the next row (or set of rows). Your query, however, can certainly include data from prior rows using the lag function. For example, this will show you the ename for the prior row in your result
SELECT empno, ename, lag(ename) over (order by empno) prior_ename
FROM emp
ORDER BY empno
In a PL/SQL loop, you can also obviously have a local variable that has the data from the previous row that was fetched and use that to compare against the data from the most current row.
Please use ANALYTICAL function to check for prior or post rows. LEAD,LAG functions are best way to do this.
I have a procedure which returns ref cursor as output parameter. I need to find a way to get the count of no.of records in the cursor. Currently I have count fetched by repeating the same select query which is hindering the performance.
ex:
create or replace package temp
TYPE metacur IS REF CURSOR;
PROCEDURE prcSumm (
pStartDate IN DATE,
pEndDate IN DATE,
pKey IN NUMBER,
pCursor OUT metacur
) ;
package body temp is
procedure prcSumm(
pStartDate IN DATE,
pEndDate IN DATE,
pKey IN NUMBER,
pCursor OUT metacur
)
IS
vCount NUMBER;
BEGIN
vCount := 0;
select count(*) into vCount
from customer c, program p, custprog cp
where c.custno = cp.custno
and cp.programid = p.programid
and p.programid = pKey
and c.lastupdate >= pStartDate
and c.lastupdate < pEndDate;
OPEN pCursor for SELECT
c.custno, p.programid, c.fname, c.lname, c.address1, c.address2, cp.plan
from customer c, program p, custprog cp
where c.custno = cp.custno
and cp.programid = p.programid
and p.programid = pKey
and c.lastupdate >= pStartDate
and c.lastupdate < pEndDate;
end prcSumm;
Is there a way to get the no.of rows in the out cursor into vCount.
Thanks!
Oracle does not, in general, know how many rows will be fetched from a cursor until the last fetch finds no more rows to return. Since Oracle doesn't know how many rows will be returned, you can't either without fetching all the rows (as you're doing here when you re-run the query).
Unless you are using a single-user system or you are using a non-default transaction isolation level (which would introduce additional complications), there is no guarantee that the number of rows that your cursor will return and the count(*) the second query returns would match. It is entirely possible that another session committed a change between the time that you opened the cursor and the time that you ran the count(*).
If you are really determined to produce an accurate count, you could add a cnt column defined as count(*) over () to the query you're using to open the cursor. Every row in the cursor would then have a column cnt which would tell you the total number of rows that will be returned. Oracle has to do more work to generate the cnt but it's less work than running the same query twice.
Architecturally, though, it doesn't make sense to return a result and a count from the same piece of code. Determining the count is something that the caller should be responsible for since the caller has to be able to iterate through the results. Every caller should be able to handle the obvious boundary cases (i.e. the query returns 0 rows) without needing a separate count. And every caller should be able to iterate through the results without needing to know how many results there will be. Every single time I've seen someone try to follow the pattern of returning a cursor and a count, the correct answer has been to redesign the procedure and fix whatever error on the caller prompted the design.
I had written a cursor in a pl/sql block. This block taking lot of time if it has more records.
How to write this without a cursor or Is there any other alternative way that will reduce the time?
Is there any alternative query to perform insert into one table and delete from another table using a single query?
DECLARE
MDLCursor SYS_REFCURSOR;
BEGIN
open MDLCursor for
select dc.dest_id, dc.digits, dc.Effectivedate, dc.expirydate
from DialCodes dc
INNER JOIN MDL d
ON dc.Dest_ID = d.Dest_ID
AND d.PriceEntity = 1
join sysmdl_calltypes s
on s.call_type_id = v_CallType_ID
and s.dest_id = dc.Dest_ID
and s.call_type_id not in
(select calltype_id from ignore_calltype_for_routing)
order by length(dc.digits) desc, dc.digits desc;
loop
fetch MDLCursor
into v_mdldest_id, v_mdldigits, v_mdlEffectiveDate, v_mdlExpDate;
insert into tt_pendingcost_temp
(Dest_ID,
Digits,
CCASDigits,
Destination,
tariff_id,
NewCost,
Effectivedate,
ExpiryDate,
previous,
Currency)
select v_mdldest_id,
Digits,
v_mdldigits,
Destination,
tariff_id,
NewCost,
Effectivedate,
ExpiryDate,
previous,
Currency
FROM tt_PendingCost
where substr(Digits, 1, 2) = substr(v_MDLDigits, 1, 2)
and instr(Digits, v_MDLDigits) = 1
and v_mdlEffectiveDate <= effectivedate
and (v_mdlExpDate > effectivedate or v_mdlExpDate is null);
if SQL%ROWCOUNT > 0 then
delete FROM tt_PendingCost
where substr(Digits, 1, 2) = substr(v_MDLDigits, 1, 2)
and instr(Digits, v_MDLDigits) = 1
and v_mdlEffectiveDate <= effectivedate
and (v_mdlExpDate > effectivedate or v_mdlExpDate is null);
end if;
exit when MDLCursor%NOTFOUND;
end loop;
close MDLCursor;
END;
I don't have your tables and your data so I can only guess at a couple of things that would be slowing you down.
Firstly, the query used in your cursor has an ORDER BY clause in it. If this query returns a lot of rows, Oracle has to fetch them all and sort them all before it can return the first row. If this query typically returns a lot of results, and you don't particularly need it to return sorted results, you may find your PL/SQL block speeds up a bit if you drop the ORDER BY. That way, you can start getting results out of the cursor without needing to fetch all the results, store them somewhere and sort them first.
Secondly, the following is the WHERE clause used in your INSERT INTO ... SELECT ... and DELETE FROM ... statements:
where substr(Digits, 1, 2) = substr(v_MDLDigits, 1, 2)
and instr(Digits, v_MDLDigits) = 1
and v_mdlEffectiveDate <= effectivedate
and (v_mdlExpDate > effectivedate or v_mdlExpDate is null);
I don't see how Oracle can make effective use of indexes with any of these conditions. It would therefore have to do a full table scan each time.
The last two conditions seem reasonable and there doesn't seem a lot that can be done with them. I'd like to focus on the first two conditions as I think there's more scope for improvement with them.
The second of the four conditions is
instr(Digits, v_MDLDigits) = 1
This condition holds if and only if Digits starts with the contents of v_MDLDigits. A better way of writing this would be
Digits LIKE v_MDLDigits || '%'
The advantage of using LIKE in this situation instead of INSTR is that Oracle can make use of indexes when using LIKE. If you have an index on the Digits column, Oracle will be able to use it with this query. Oracle would then be able to focus in on those rows that start with the digits in v_MDLDigits instead of doing a full table scan.
The first of the four conditions is:
substr(Digits, 1, 2) = substr(v_MDLDigits, 1, 2)
If v_MDLDigits has length at least 2, and all entries in the Digits columns also have length at least 2, then this condition is redundant since it is implied by the previous one we looked at.
I'm not sure why you would have a condition like this. The only reason I can think why you might have this condition is if you have a functional index on substr(Digits, 1, 2). If not, I would be tempted to remove this substr condition altogether.
I don't think the cursor is what is making this procedure run slowly, and there's no single statement I know of that can insert into one table and delete from another. To make this procedure speed up I think you just need to tune the queries a bit.