How can I retrieve the last non-null value in a row of a table in DB?
Assuming values are non-nulls and then all nulls.
For example, assume there are 5 columns in a table (A B C D E). Here is a sample row data:
A B C D E
1 2 NULL NULL NULL
1 2 3 NULL NULL
I need to get for 1st row - value 2, for second row - value 3. Rows are processed in a cursor.
Thank you
Just use coalesce():
select coalesce(e, d, c, b, a) as last_not_null
from t;
Sql do have a inbuilt function COALESCE for non-null expression in the list.
The COALESCE() function returns the first non-null expression in a list.
Related
Ok so this gets me the count of how many Records of type A are blank in column B
SELECT A, Count(B)
FROM `table1`
where
B = ""
group by A
it gives me a table
A
B
First
564
Second
1985
And that is great. But I want this to summarize by counting blanks in multiple columns, not just blanks in column B, like this:
A
B
C
First
564
9001
Second
1985
223
I have an intuition that this is done by creating another table first that would look like this
A
Column
Value
First
"B"
B value
First
"C"
C value
Second
"B"
B value
Second
"C"
C value
for every document, so you can count blanks, but I'm not sure how to get there. Is this the right approach? or is there a much simpler version using pivot tables or similar?
You could try using a conditional sum,
select A,
Sum(case when b='' then 1 end) B,
Sum(case when c='' then 1 end) C
from t
group by A
I am trying to figure a way to sum a column based on conditions are create a new column with the aggregated values.
I need to sum column D based based on column condition from Column A, B and C. Value 1 in column A is the exception. The output that is required is as follows -
Where a new column E is created that sums Column D(2958673+2166646) by the condition of Column A(10,12) and Column B(20) and Column C(3) in Row 1. Similarly, Column D(1799504) by the condition of Column A(12) and Column B(20) and Column C(4) in Row 2
This is perhaps a comment, but it is too long.
I simply do not follow the logic that you want to implement. Your results can be produced by a simple query with filtering:
select a, b, c, d as d, d as e
from t
where a = 1;
EDIT:
Perhaps this is what you want?
select 1, b, c,
sum(d) filter (where a = 1) as d,
sum(d) filter (where a in (10, 12)) as e
from t
group by b, c;
Absolute rookie at SQL so apologies upfront if not possible or absurd.
Single table in SQL-Lite
First of all I want to filter the table to only return rows where the difference between decimal in column A and decimal in column B is more than 3
Then for each row I want to subtract integer in column C from integer in column D to give result E. And then I want to know whether the decimal in column A or decimal in column B is closer to result E
Thanks!
The code below basically uses a subquery to keep all the needed values handy, a CASE operator to make the decision, and the ABS() function to determine absolute distance.
select A, B, C, D, E,
case when ABS(A-E) < abs(B-E) then 'A' else 'B' end [Closer_Value]
from (
select A, B, C, D, (C-D) as [E]
from YourTable
where abs(A-B) > 3
) as Temp
I need some advice in google query language.
I want to count rows depending on date and a condition. But if the condition is not met, it should return 0.
What I'm trying to achieve:
Date Starts
05.09.2018 0
06.09.2018 3
07.09.2018 0
What I get:
Date Starts
06.09.2018 3
The query looks like =Query(Test!$A2:P; "select P, count(B) where (B contains 'starts') group by P label count(B) 'Starts'")
P contains ascending datevalues and B an event (like start in this case).
How can I force output a 0 for the dates with no entry containing "start"?
The main point is to get all needed data in one table in ascending order. But this is only working, if every day has an entry. If there is no entry for a day, the results for "start" do not match the datevalue in column A. 3 in column D would be in the first row of the table then.
I need it like this:
A B C D
Date Logins Sessions Starts
05.09.2018 1 2 0
06.09.2018 3 4 3
07.09.2018 4 5 0
Maybe this is easy to fix, but I don't see it.
Thanks in advance!
You can do some pre-processing before the query. Ex: check if column B contains 'start' with regexmatch and use a double unary (--) to force the boolean values into 1's and 0's. The use query to sum.
=Query(Arrayformula({--regexmatch(Test!$B2:B; "start")\ Test!$A2:P}); "select Col17, sum(Col1) where Col17 is not null group by Col17 label sum(Col1) 'Starts'")
Change ranges to suit.
just a simple question but somehow I can't find an answer here.
I have two columns (A and B). Both contains numbers with zeros and null. I would like to get a division one by the other to get information about the ratio between each single row but I am getting ORA-01476.
I know the divisior is equal to zero but I would like to get in this row a number and not an error for whole query
A B
1 5
2 Null
3 0
NULL 3
0 4
4
I am using sql developer.
If you divide a number by zero you get an error, because the answer to such division is undefined. SQL, however, has a value for undefined: NULL. So make the result NULLinstead:
select a, b, case when b = 0 then null else a / b end as ratio
from mytable;
or
select a, b, a / case when b = 0 then null else b end as ratio
from mytable;
This is standard SQL and works in Oracle as well as in about every other RDBMS. Oracle also provides the function NULLIF as a shorter way to write the expression in the second query.
You can use nullif to return null instead of raising an error:
select A / nullif(B, 0) as division
from YourTable
If your numbers are stored as varchar, cast them to numbers before using them:
select to_number(A) / nullif(to_number(B), 0) as division
from YourTable