I have a very large table that I need to retrieve data from. The table looks like this:
A B C D
1 foo 4 q
1 fool 2 p
1 fools 13 a
2 pho 5 d
3 phone 14 g
3 phones 6 f
I'm trying to run something like:
select max(B) from table where A = 1 union
select max(B) from table where A = 2 union
.
.
.
select max(B) from table where A = 50000;
What I want is to get:
1 -> fools
2 -> pho
3 -> phones
I have about 50,000 records to run this query for.
This above approach theoretically works (I tried on a small subset), but I think it's inefficient to have one select query for each of the 50000 values.
This also resulted in a process out of memory error.
Is there a way I can run this in a single query?
I tried:
select max(B) from table where A in (first group of 1000) union
select max(B) from table where A in (1000...2000) union
.
.
.
select max(B) from table where A in (40000...50000)
But this gives me only one max value per select query (and I understand why)
What I really want is 50000 max values.
Is there a way for me to get the value of max(B) for each item in the list if I use
select max(B) from table where A in (...)
Thank you!
It looks like you just need to use GROUP BY, like this:
select A, max(B)
from table
group by A
order by A
Let me know if I'm missing something.
Related
I have a query that gets contract_types 1 to 10. This query is being used in an SSRS report to filter out a larger dataset. I am using -1 for nulls and -2 for all.
I would like to know how we would allow multiple values - does oracle concatenate the inputs together so '1,2,3' would be passed in? Say we get select -1,0,1 in SSRS, how could we alter the bottom query to return values?
My query to get ContractTypes:
SELECT
ContractType,
CASE WHEN ContractType = -2 THEN 'All'
WHEN ContractType = -1 THEN'Null'
ELSE to_Char(ContractType)
END AS DisplayFigure
FROM ContractTypes
which returns
ContractType DisplayFig
-1 Null
0 0
1 1
2 2
3 3
4 4
5 5
6 6
7 7
8 8
9 9
10 10
This currently is only returning single values or all, not muliple values:
SELECT *
FROM Employee
WHERE NVL(CONTRACT_TYPE, -1) = :contract_type or :contract_type = -2
I'm assuming we want to do something like:
WHERE NVL(CONTRACT_TYPE, -1) IN (:contract_type)
But this doesn't seem to work.
Data in Employee
Name ContractType
Bob 1
Sue 0
Bill Null
Joe 2
In my report, I want to be able to select contract_type as -1(null),0,1 using the 'allow muliple values' checkbox. At the moment, I can only select either 'all' using my -2 value, or single contract types.
My input would be: contract type = -1,1,2
My output would be Bill, Bob, Joe.
This is how I'm executing my code
I use SSRS with Oracle a lot so I see where you're coming from. Thankfully, they work pretty well together.
First make sure the parameter is set to allow multiple values. This adds a Select All option to your dropdown so you don't have to worry about adding a special case for "All". You'll want to make sure the dataset for the parameter has a row with -1 as the Value and a friendly description for the Label.
Next, the WHERE clause would be just as you mentioned:
WHERE NVL(CONTRACT_TYPE, -1) IN (:contract_type)
SSRS automatically populates the values. There is no XML or string manipulation needed. Keep in mind that this will not work with single-value parameters.
If for some reason this still doesn't work as expected in your environment, there is another workaround you can use which is more universal and works even with ODBC connections.
In the dataset parameter properties, use an expression like this to concatenate the values into a single, comma-separated string:
="," + Join(Parameters!Parameter.Value, ",") + ","
Then use an expression like this in your WHERE clause:
where :parameter like '%,' + Column + ',%'
Obviously, this is less efficient because it most likely won't be using an index, but it works.
I don't know SSRS, but - if I understood you correctly, you'll have to split that comma-separated values list into rows. Something like in this example:
SQL> select *
2 from dept
3 where deptno in (select regexp_substr('&&contract_type', '[^,]+', 1, level)
4 from dual
5 connect by level <= regexp_count('&&contract_type', ',') + 1
6 );
Enter value for contract_type: 10,20,40
DEPTNO DNAME LOC
---------- -------------------- --------------------
20 RESEARCH DALLAS
10 ACCOUNTING NEW YORK
40 OPERATIONS BOSTON
SQL>
Applied to your code:
select *
from employee
where nvl(contract_type, -1) in (select regexp_substr(:contract_type, '[^,]+', 1, level)
from dual
connect by level <= regexp_substr(:contract_type, ',') + 1
)
If you have the comma separated list of numbers and then if you like to split it then, the below seems simple and easy to maintain.
select to_number(column_value) from xmltable(:val);
Inputs: 1,2,3,4
Output:
I guess I understood your problem. If I am correct the below should solve your problem:
with inputs(Name, ContractType) as
(
select 'Bob', 1 from dual union all
select 'Sue', 0 from dual union all
select 'Bill', Null from dual union all
select 'Joe', 2 from dual
)
select *
from inputs
where decode(:ContractType,'-2',-2,nvl(ContractType,-1)) in (select to_number(column_value) from xmltable(:ContractType))
Inputs: -1,1,2
Output:
Inputs: -2
Output:
I have a table with Lots of cost columns for each Key
TableA
SK1 SK2 Col1 Col2 Col3..... Col50 Flg(Y/N)
1 2 10 20 30 ...... 500 Y
1 2 10 20 30 ...... 500 N
2 2 10 20 30 ...... 500 N
I need to aggregate(sum) of all values and then check if there are any values with Y then add them to new tableB.
Here table A record combination (1,2) for (sk1,sk2) should be returned.
The i have written query is to select lisr of all cols and add as group by.
We have lots of data so this query is taking too long to run. Any chance to relook into this and do so that it can become faster.
select
Sk1,
Sk2,
nvl(sum(col3),0),
nvl(sum(col4))0,
.....
nvl(sum(col50))
from table A
group by Sk1,
Sk2
Iam using this as part of large query where in many other calculations are performed on top of this.
Working out whether any of a grouped set of records contains a 'Y' would be as simple as ...
select ...
from ...
group by ...
having max(flg) = 'Y'
For now i have created a temporary table and have loaded all the data into it.
If you are using this as part of large query, did you try WITH option?
It could be like this
WITH SUM_DATA AS (select col1, col2, nvl(sum(col3),0), nvl(sum(col4))0, ..... nvl(sum(col50)) from table A group by col1, col2)
SELECT xyz
FROM abc, sum_data
WHERE abc.join_col = sum_data.join_col
More help here
i have problem with this case, i have log table that has many same ID with diferent condition. i want to select two max condition from this. i've tried but it just show one record only, not every record in table.
Here's my records table:
order_id seq status____________________
1256 2 4
1256 1 2
1257 0 2
1257 3 1
Here my code:
WITH t AS(
SELECT x.order_id
,MAX(y.seq) AS seq2
,MAX(y.extern_order_status) AS status
FROM t_order_demand x
JOIN t_order_log y
ON x.order_id = y.order_id
where x.order_id like '%12%'
GROUP BY x.order_id)
SELECT *
FROM t
WHERE (t.seq2 || t.status) IN (SELECT MAX(tt.seq2 || tt.status) FROM t tt);
this query works, but sometime it gave wrong value or just show some records, not every records.
i want the result is like this:
order_id seq2 status____________________
1256 2 4
1257 3 2
I think you just want an aggregation:
select d.order_id, max(l.seq2) as seq2, max(l.status) as status
from t_order_demand d join
t_order_log l
on d.order_id = l.order_id
where d.order_id like '%12%'
group by d.order_id;
I'm not sure what your final where clause is supposed to do, but it appears to do unnecessary filtering, compared to what you want.
I'm tring to use hive to analysis our log, and I have a question.
Assume we have some data like this:
A 1
A 1
A 1
B 1
C 1
B 1
How can I make it like this in hive table(order is not important, I just want to merge them) ?
A 1
B 1
C 1
without pre-process it with awk/sed or something like that?
Thanks!
Step 1: Create a Hive table for input data set .
create table if not exists table1 (fld1 string, fld2 string ) ROW FORMAT DELIMITED FIELDS TERMINATED BY '\t';
(i assumed field seprator is \t, you can replace it with actual separator)
Step 2 : Run below to get the merge data you are looking for
create table table2 as select fld1,fld2 from table1 group by fld1,fld2 ;
I tried this for below input set
hive (default)> select * from table1;
OK
A 1
A 1
A 1
B 1
C 1
B 1
create table table4 as select fld1,fld2 from table1 group by fld1,fld2 ;
hive (default)> select * from table4;
OK
A 1
B 1
C 1
You can use external table as well , but for simplicity I have used managed table here.
One idea.. you could create a table around the first file (called 'oldtable').
Then run something like this....
create table newtable select field1, max(field) from oldtable group by field1;
Not sure I have the syntax right, but the idea is to get unique values of the first field, and only one of the second. Make sense?
For merging the data, we can also use "UNION ALL" , it can also merge two different types of datatypes.
insert overwrite into table test1
(select x.* from t1 x )
UNION ALL
(select y.* from t2 y);
here we are merging two tables data (t1 and t2) into one single table test1.
There's no way to pre-process the data while it's being loaded without using an external program. You could use a view if you'd like to keep the original data intact.
hive> SELECT * FROM table1;
OK
A 1
A 1
A 1
B 1
C 1
B 1
B 2 # Added to show it will group correctly with different values
hive> CREATE VIEW table2 (fld1, fld2) AS SELECT fld1, fld2 FROM table1 GROUP BY fld1, fld2;
hive> SELECT * FROM table2;
OK
A 1
B 1
B 2
C 1
I need to get the result of concatenating 2 similar querys' resulsets. For some reason had to split the original query in 2, both with their corresponding order by clause. Should be something like (this is an oversimplification of the original queries)
Query1: Select name, age from person where age=10
Resultset1:
Person1, 10
Person3, 10
Query2: Select name, age from person where age=20
Resultset1:
Person2, 20
Person6, 20
The expected result:
Person1, 10
Person3, 10
Person2, 20
Person6, 20
I can not simply use Query1 UNION Query2.
Below the 2 original querys:
(#1)
select cp.CP_ID, cpi.CI_DESCRIPCION, cp.CP_CODIGOJERARQUIZADO, cp.CP_ESGASTO as gasto, cp.CP_CONCEPTOPADRE, LEVEL
from TGCCP_ConceptoPagoIng cp
left join tgcci_ConceptoPagoIngIdioma cpi on cpi.CI_IDCONCEPTOPAGOING = cp.CP_ID and cpi.CI_IDIDIOMA = 1
start with ((CP_CONCEPTOPADRE is null) and (**cp.CP_ESGASTO = 1**))
connect by prior cp.CP_ID = cp.CP_CONCEPTOPADRE
order siblings by CP_CODIGOJERARQUIZADO
(#2)
select cp.CP_ID, cpi.CI_DESCRIPCION, cp.CP_CODIGOJERARQUIZADO, cp.CP_ESGASTO as gasto, cp.CP_CONCEPTOPADRE, LEVEL
from TGCCP_ConceptoPagoIng cp
left join tgcci_ConceptoPagoIngIdioma cpi on cpi.CI_IDCONCEPTOPAGOING = cp.CP_ID and cpi.CI_IDIDIOMA = 1
start with ((CP_CONCEPTOPADRE is null) and (**cp.CP_ESGASTO = 2**))
connect by prior cp.CP_ID = cp.CP_CONCEPTOPADRE
order siblings by CP_CODIGOJERARQUIZADO
I think you want a
select * from ( first query )
UNION ALL
select * from ( second query )
Where first query and second query are the queries from above, so you are turning them into subqueries, thus preserving the order by clauses.
OK, well, I'm not fully certain why you need it this way, but if Oracle won't allow you to do a UNION, or it screws up the ordering when you do, I would try creating a pipelined table function.
An example here
Basically, you'd create a procedure that ran both queries, first one, then the other, putting the results of each into the returned dataset.
It looks like you are looking for a MULTISET UNION. Which can only be used from version 10 upwards.
Regards,
Rob.
You could combine your queries as subqueries and do a single order by on the outer query:
select * from (
<query 1 with its order by>
UNION ALL
<query 2 with its order by>
)
order by column1, column2;
Alternatively, you can implement in PL/SQL the equivalent of a sort merge join with two cursors, but that's unnecessarily complicated.
this solution works perfectly:
select * from ( first query )
UNION ALL
select * from ( second query )
I appreciate everyone that have taken the time to answer.
regards.
For your example:
Select name, age from person where age in (10,20)
or
Select name, age from person where age = 10 or age = 20
However I'm guessing this is not what you need :)