I have a problem with counting strings in my concat syntax.
i concat 4 columns and the result is as below.
(complete,complete,incomplete,incomplete).
now I want to score them base on the number of 'complete'. for example if there are 4 complete it is 100%, if there are 3 complete it is 60% and so on.
is there any way to do this in sql
I suspect that you want aggregation like this:
select avg(case when val = 'complete' then 1.0 else 0 end) as complete_ratio
Related
I have a scenario where I'm trying not to count a row where it has a zero, blank or NULL. But I'm not sure how to. I have used ISNULL to replace it with blank but the result shows zero. I don't want zero because it messes up my averages etc. The screen shot below should show 17 in the bottom as total but it's showing 18 because it's counting the null as row count. This null row has an N/A as a value in the data set but my count counts it as a row. I'm using count() because I have many other columns so I can not change the count(). Any ideas on how to show the total as 17 instead of 18?
Thank you
Some SQL implementations (I think this is also proper ANSI standard but don't know that for sure) exhibit a different behaviour for COUNT(*) VS COUNT(field).
The former will include NULLs, the latter will exclude them.
you can use SUM like this
SELECT SUM(CASE WHEN ISNULL(testeq4,'') <> '' THEN 1 ELSE 0 end)
FROM YourTable
Try this:
SELECT SUM(CASE WHEN ISNULL(TestQ4,0)=0 THEN 0 ELSE 1 END)
I've been tasked with coming up with a solution for a problem that was found this morning. I have a query that I need to do some math with. I have three pertinent columns.
SELECT lQ.[QUANTITY], lQ.[FORM_FACTOR_ID], oQ.[INDIVIDUAL_PACKAGING]
FROM [dbo].[AOF_ORDER_LINE_QUEUE] as lQ
LEFT JOIN [dbo].[AOF_ORDER_QUEUE] AS oQ
ON lQ.[SALES_ORDER_NUMBER] = oQ.[SALES_ORDER_NUMBER]
I can see myself doing this in a loop easily in languages I know best. It doesn't seem that looping is a good thing to do in SQL based on some preliminary research so I am reaching out for suggestions.
I need to output a total value which is a conditional sum of lQ.[QUANTITY]. The condition is if oQ.[FORM_FACTOR_ID] is equal to 1 then the output for that particular row is equal to the value of lQ.[QUANTITY]. If oQ.[FORM_FACTOR_ID] is equal to 2 then if oQ.[INDIVIDUAL_PACKAGING] is true, then the output of that particular row in the query is equal to lQ.[QUANTITY]. If the value is false, then the output of that particular row in the query is divided by 2. The final output needs to be a single integer.
QUANTITY FORM_FACTOR_ID INDIVIDUAL_PACKAGING
4 2 1
5 1 1
I would need a query that outputs the value 7 for the above table.
QUANTITY FORM_FACTOR_ID INDIVIDUAL_PACKAGING
4 2 0
5 2 0
That same query needs to output 5 for the above table.
What would be the best way to go about doing this?
If I understand the question correctly, you just want conditional aggregation -- a CASE as an argument to SUM().
If I follow the logic, it would look like:
SELECT SUM(CASE WHEN oq.FORM_FACTOR_ID = 1 THEN lQ.QUANTITY
WHEN oQ.FORM_FACTOR_ID = 2 AND oQ.INDIVIDUAL_PACKAGING = 1 THEN lQ.QUANTITY
WHEN oQ.FORM_FACTOR_ID = 2 AND oQ.INDIVIDUAL_PACKAGING = 0 THEN lQ.QUANTITY / 2
END)
FROM [dbo].[AOF_ORDER_LINE_QUEUE] lQ LEFT JOIN
[dbo].[AOF_ORDER_QUEUE] oQ
ON lQ.[SALES_ORDER_NUMBER] = oQ.[SALES_ORDER_NUMBER];
i guess i just lack the keywords to search, but this is burning on my mind:
how can i add a condition to the sum-function in the select-statement like
select sum(a), sum(b where c=1) from db;?
this means, i want to see the sum of column a and the sum of column b, but only of the records in column b of which column c has the value 1.
the output of heidi just says "bad syntac near WHERE". may there be any other way?
thanks in advance and best regards from Berlin, joachim
The exact syntax may differ depending on the database engine, however it will be along the lines of
SELECT
sum(a),
sum(CASE WHEN c = 1 THEN b ELSE 0 END)
FROM
db
select sum(case when c=1 then b else 0 end)
This technique is useful when you need a lot of aggregates on the same set of data - you can query the entire table without applying a where filter, and have a bunch of these which give you aggregated data for a specific filter.
It's also useful when you need a lot of counts based on filters - you can do sums of 1 or 0:
select sum(case when {somecondition} then 1 else 0 end)
I've got a table called datapoints with about 150 columns and 2600 rows. I know, 150 columns is too much, but I got this db after importing a csv and it is not possible to shrink the number of columns.
I have to get some statistical stuff out of the data. E.g. one question would be:
Give me the total number of fields (of all columns), which are null. Does somebody have any idea how I can do this efficiently?
For one column it isn't a problem:
SELECT count(*) FROM datapoints tb1 where 'tb1'.'column1' is null;
But how can I solve this for all columns together, without doing it by hand for every column?
Best,
Michael
Building on Lamak's idea, how about this idea:
SELECT (N * COUNT(*)) - (
COUNT(COLUMN_1)
+ COUNT(COLUMN_2)
+ ...
+ COUNT(COLUMN_N)
)
FROM DATAPOINTS;
where N is the number of columns. The trick will be in making the summation series of COUNT(column), but that shouldn't be too terrible with a good text editor and/or spreadsheet.
i don't think there is an easy way to do it. i'd get started on the 150 queries. you only have to replace one word (column name) each time.
Well, COUNT (and most aggregations funcions) ignore NULL values. In your case, since you are using COUNT(*), it counts every row in the table, but you can do that on any column. Something like this:
SELECT TotalRows-Column1NotNullCount, etc
FROM (
SELECT COUNT(1) TotalRows,
COUNT(column1) Column1NotNullCount,
COUNT(column2) Column2NotNullCount,
COUNT(column3) Column3NotNullCount ....
FROM datapoints) A
To get started it's often helpful to use a visual query tool to generate a field list and then use cut/paste/search/replace or manipulation in a spreadsheet program to transform it into what is needed. To do it all in one step you can use something like:
SELECT SUM(CASE COLUMN1 WHEN NULL THEN 1 ELSE 0 END) +
SUM(CASE COLUMN2 WHEN NULL THEN 1 ELSE 0 END) +
SUM(CASE COLUMN3 WHEN NULL THEN 1 ELSE 0 END) +
...
FROM DATAPOINTS;
With a visual query builder you can quickly generate:
SELECT COLUMN1, COLUMN2, COLUMN3 ... FROM DATAPOINTS;
You can then replace the comma with all the text that needs to appear between two field names followed by fixing up the first and last fields. So in the example search for "," and replace with " WHEN NULL 1 ELSE 0 END) + SUM(CASE " and then fix up the first and last fields.
I have result set like -
id achieved
1 0
2 1
3 1
4 0
5 0
The Percentage should be 2/5 i.e. 40 %. How can I write a SQL Query to achieve something like this ? I would prefer not to use and nested select as the actual query is already doing quite a bit. Thanks !
select avg(achieved) from ...
Note that you will have to use a group by function to include categories:
select gender, avg(achieved) from ... group by gender