"I am trying to achieve dual command in big query"
"I tried using the temp tables but not able to achieve it"
Oracle query: SELECT LEVEL - 1 F FROM
DUAL CONNECT BY LEVEL <= 2
"I expect the output in below format "
F
1
2
I have salary table with salaries : 50$ and 200$
I want to have duplicate of each row : 50$ ,-50$,200$ and -200$ is the output which i am expecting like 4 rows in total
You can use
SELECT
1
from (
select SESSION_USER())
to return a resultset with just one row.
Since BigQuery doesn't support CONNECT BY clause and since you want to get a positive and negative values from your data, you could try using a simple query like this one:
SELECT my_value FROM `project.dataset.table`
UNION ALL
SELECT -my_value FROM `project.dataset.table`
Notice the - in the second query as it'll give you negative values.
Hope it helps.
Related
I have a simple inline view that contains 2 columns.
-----------------
rn | val
-----------------
0 | A
... | ...
25 | Z
I am trying to select a val by matching the rn randomly by using the dbms_random.value() method as in
with d (rn, val) as
(
select level-1, chr(64+level) from dual connect by level <= 26
)
select * from d
where rn = floor(dbms_random.value()*25)
;
My expectation is it should return one row only without failing.
But now and then I get multiple rows returned or no rows at all.
on the other hand,
>>select floor(dbms_random.value()*25) from dual connect by level <1000
returns a whole number for each row and I failed to see any abnormality.
What am I missing here?
The problem is that the random value is recalculated for each row. So, you might get two random values that match the value -- or go through all the values and never get a hit.
One way to get around this is:
select d.*
from (select d.*
from d
order by dbms_random.value()
) d
where rownum = 1;
There are more efficient ways to calculate a random number, but this is intended to be a simple modification to your existing query.
You also might want to ask another question. This question starts with a description of a table that is not used, and then the question is about a query that doesn't use the table. Ask another question, describing the table and the real problem you are having -- along with sample data and desired results.
I have a very very small database that I am needing to return a field from a specific row.
My table looks like this (simplified)
Material_Reading Table
pointID Material_Name
123 WoodFloor
456 Carpet
789 Drywall
111 Drywall
222 Carpet
I need to be able to group these together and see the different kinds (WoodFloor, Carpet, and Drywall) and need to be able to select which one I want and have that returned. So my select statement would put the various different types in a list and then I could have a variable which would select one of the rows - 1, 2, 3 for example.
I hope that makes sense, this is somewhat a non-standard implementation because its a filemaker database unfortunately, so itstead of one big SQL statement doing all I need I will have several that will each select an individual row that I indicate.
What I have tried so far:
SELECT DISTINCT Material_Name FROM MATERIAL_READING WHERE Room_KF = $roomVariable
This works and returns a list of all my material names which are in the room indicated by the room variable. But I cant get a specific one by supplying a row number.
I have tried using LIMIT 1 OFFSET 1. Possibly not supported by Filemaker or I am doing it wrong, I tried it like this - it gives an error:
SELECT DISTINCT Material_Name FROM MATERIAL_READING WHERE _Room_KF = $roomVariable ORDER BY Material_Name LIMIT 1 OFFSET 1
I am able to use ORDER BY like this:
SELECT DISTINCT Material_Name FROM MATERIAL_READING WHERE Room_KF = $roomVariable ORDER BY Material_Name
In MSSQL
SELECT DISTINCT Material_Name
FROM MATERIAL_READING
WHERE _Room_KF = 'roomVariable'
ORDER BY Material_Name
OFFSET N ROWS
FETCH NEXT 5 ROWS ONLY
where N->from which row does to start
X->no.of rows to retrieve which were started from (N+1 row)
Can anyone explain the behavior of the below query:-
select level,t.*
from
( select 'one','two'from dual
union all
select 'one','two'from dual
) t
connect by level<=2
There are 2 rows in the inner query. I was expecting 4 rows of output, but i get 6 rows of output. Why is it so and how does this work?
The query starts with one of your two rows and adds both rows, then it continues with the second row and adds both rows again.
Change your query like this:
select level,t.*
from
( select 'one' from dual
union all
select 'two' from dual
) t
connect by level<=2;
This makes it easier to see what happens:
1 one
2 one
2 two
1 two
2 one
2 two
Read this http://docs.oracle.com/cd/B19306_01/server.102/b14200/queries003.htm
When level <= 1, you will get each of the records 1 time.
When level <= 2, then you will get each level 1 time (for level 1) + the number of records in the table
(That means for this condition 2 records having level 1 + 2*2 records having level 2. This is the reason you are getting 6 records.)
CONNECT BY LEVEL gives following number of rows
x+x2+x3+x4+...x^n = Sx^n
where n is number of LEVEL and x is number of rows in a table
Here is what I am trying to do in a Oracle SQL query:
I have an account number that is X characters long (Example: 6001055555). I have a table that has part of the same account number but most of the number is masked (Examples: 600##########, 6001######, 600244####).
I am trying to match the number passed in 6001055555 to one of the following values 600##########, 6001######, 600244####.
In this example, account number 6001055555 should return 6001###### (from the above list). I can get to the point where the lengths are the same but am not sure how to address the match - I am looking at using REGEX expressions but am not sure if that' the correct path.
You can use the regular LIKE comparison in this case:
SQL> WITH DATA AS (
2 SELECT '600##########' acct FROM dual UNION ALL
3 SELECT '6001######' acct FROM dual UNION ALL
4 SELECT '600244####' acct FROM dual
5 )
6 SELECT *
7 FROM DATA
8 WHERE '6001055555' LIKE REPLACE (acct, '#', '_');
ACCT
-------------
6001######
We're used to seeing COLUMN LIKE :var but switching terms is also valid (:var LIKE column).
If my understanding is rite, this is what u may be expecting...
select regexp_substr('6001055555',replace('600##########','#'),1) from dual;
If you got any value from this query you may conclude that the account number is matched with the masking values
This:
select *
from dual
connect by level <= i
...will return result as
1
2
3
...
i
Can the query be modified to get result row wise? i.e
1 2 3 .....i
The functionality you're after is called "pivot"--it's converting row data into columnar data. The opposite is called "unpivot". There is PIVOT/UNPIVOT syntax, but it isn't available until Oracle 11g.
On Oracle 9i+, CASE statements are used while prior to that you need to use DECODE to construct the logic so the values come out in columns. Here's an example for addressing if the limit to LEVEL is five on Oracle 9i+:
SELECT MAX(CASE WHEN LEVEL = 1 THEN LEVEL END) AS one,
MAX(CASE WHEN LEVEL = 2 THEN LEVEL END) AS two,
MAX(CASE WHEN LEVEL = 3 THEN LEVEL END) AS three,
MAX(CASE WHEN LEVEL = 4 THEN LEVEL END) AS four,
MAX(CASE WHEN LEVEL = 5 THEN LEVEL END) AS five
FROM DUAL
CONNECT BY LEVEL <= 5
The aggregate function MAX is necessary to "flatten" the resultset into a single row/record.
If you got this far, you're thinking "but I don't want to have to specify for every column--I want it to be dynamic based on i...". There's two issues:
There is a limit to the number of columns - see ORA-01792 maximum number of columns in a table or view is 1000. That goes for 8i & 9i, anyways. And frankly, needing to generate that many columns raises serious questions about what you're trying to do with the resultset, if there might be a better approach...
Dynamic requirements means using dynamic SQL
Try this:
select trim(both ',' from sys_connect_by_path(level, ',')) as string
from dual
where level = 100
connect by level <= 100
update: Testing the output:
SQL>
SQL> select trim(both ',' from sys_connect_by_path(level, ',')) as string
2 from dual
3 where level = 20
4 connect by level <= 20
5 /
STRING
--------------------------------------------------------------------------------
1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20
another update: Guess I haven't read all comments well enough before posting, sorry. :) If you need to select each number as a separate column, then yes, see, OMG Ponies' answer - it's either pivot or dynamic SQL. :)