I have the following query:
SELECT i.[Race / Ethnicity], NZ(Count(i.[Race / Ethnicity]),0) AS [Count Ethnicity]
FROM Information AS i
LEFT JOIN Visits AS v
ON i.[Customer ID] = v.[Customer ID]
WHERE (Month(v.[Visit Date]) = [Forms]![Report Generator]![month_box_rpt]
AND Year(v.[Visit Date]) = [Forms]![Report Generator]!
[year_box_rpt]) and (Month(i.[Signup Date]) = [Forms]![Report Generator]![month_box_rpt] AND Year(i.[Signup Date]) = [Forms]![Report Generator]![year_box_rpt])
GROUP BY (i.[Race / Ethnicity]);
It takes month ([month_box_rpt]) and year ([year_box_rpt]) values from a form and compares to month and year values for a value in one of the tables ([Visit Date]) and returns a count of people of different ethnicities (GROUP BY (i.[Race / Ethnicity])).
The query works. However if there are zero records that meet the specified criteria I get a blank return when the query is run.
How can I get a result that has each of my universe of ethnicities and a zero value if there are no people of that ethnicity that meet the criteria?
Example:
Race / Ethnicity Count
Asian 0
Black 0
White 0
or (if some groups have values):
Race / Ethnicity Count
Asian 0
Black 3
White 2
Right now the above query returns:
Race / Ethnicity Count
or:
Race / Ethnicity Count
Black 3
White 2
I believe it involves a sub-query and have tried several but haven't been able to get it to work.
Thanks in advance for guidance.
Left Join the results of your aggregate query with another table or query that contains a single row for each of the Ethnicity values and nothing else.. join on Ethnicity = Ethnicity
Related
I have a schema with sex(m/f),state_name(all states of a country), student_name,and education (phd,ms).
I use following query to return total males or females in each category of education for every state.
select sex,education,count(*) from mytable group by education,sex;
How can I write a query that returns the arithmetic ratio of (male divided by female) for each education in every state?
I am trying to get to query that gives me gender ratio across education tiers for each state (I got count above, but I could not figure out how to do arithmetic division)
You can do conditional aggregation:
select education, sum(sex = 'male') / nullif(sum(sex = 'female'), 0) ratio
from mytable
group by education
I'm doing a left join on a table to get the number of leads we've generated today and how many times we've called those leads. I figured a left join would be the best thing to do, so I wrote the following query:
SELECT
COUNT(rad.phone_number) as lead_number, rals.lead_source_name as source, COUNT(racl.phone_number) as calls, SUM(case when racl.contacted = 1 then 1 else 0 end) as contacted
FROM reporting_app_data rad
LEFT JOIN reporting_app_call_logs racl ON rad.phone_number = racl.phone_number, reporting_app_lead_sources rals
WHERE DATE(rad.created_at) = CURDATE() AND rals.list_id = rad.lead_source
GROUP BY rad.lead_source;
But the problem with that, is that if in the reporting_app_call_logs table, there are multiple entries for the same phone number (so a phone number has been called multiple times that day), the lead_number (which I want to count how many leads were generated on the current day grouped by lead_source) equals how many calls there are. So the count from the LEFT table equals the count from the RIGHT table.
How do I write a SQL query that gets the number of leads and the total number of calls per lead source?
Try COUNT(DISTINCT expression)
In other words, change COUNT(rad.phone_number) to COUNT(DISTINCT rad.phone_number)
I am looking for an efficient alternative to subqueries/joins for this query. Let's say I a table that stores information about companies with the following columns:
name: the name of the company
state: the state the company is located
in
revenue: the annual revenue of the company
employees: how many
employees this company has
active_business: wether or not the company
is in business (1 = yes, 0 = no)
Let's say that from this table, I want to find out how many companies in each state meet the requirement for some minimum amount of revenue, and also how many companies meet the requirement for some minimum number of employees. This can be expressed as the following subquery (can also be written as a a join):
SELECT state,
(
SELECT count(*)
FROM records AS a
WHERE a.state = records.state
AND a.revenue > 1000000
) AS companies_with_min_revenue,
(
SELECT count(*)
FROM records AS a
WHERE a.state = records.state
AND a.employees > 10
) AS companies_with_min_employees
FROM records
WHERE active_business = 1
GROUP BY state
My question is this. Can I do this without the subqueries or joins? Since the query is already iterating over each row (there's no indexes), is there some way I can add a condition that if the row meets the minimum revenue requirements and is in the same state, it will increment some sort of counter for the query (similar to map/reduce)?
I think CASE and SUM will solve it:
SELECT state
, SUM(CASE WHEN R.revenue > 1000000 THEN 1 ELSE 0 END) AS companies_with_min_revenue
, SUM(CASE WHEN R.employees > 10 THEN 1 ELSE 0 END) AS companies_with_min_employees
FROM records R
WHERE R.active_business = 1
GROUP BY R.state
As you can see, we will have a value of 1 per record with a revenue of greater than 1000000 (else 0), then we'll take the sum. The same goes with the other column.
Thanks to this StackOverflow question. You'll find this when you search "sql conditional count" in google.
I have a table (tblExam) showing exam data score designed as follow:
Exam Name: String
Score: number(pecent)
Basically I am trying to pull the records by Exam name where the score are less than a specific amount (0.695 in my case).
I am using the following statement to get the results:
SELECT DISTINCTROW tblExam.name, Count(tblExam.name) AS CountOfName
FROM tblExam WHERE (((tblExam.Score)<0.695))
GROUP BY tblExam.name;
This works fine but does not display the exam that have 0 records more than 0.695; in other words I am getting this:
Exam Name count
firstExam 2
secondExam 1
thirdExam 3
The count of 0 and any exams with score above 0.695 do not show up. What I would like is something like this:
Exam Name count
firstExam 2
secondExam 1
thirdExam 3
fourthExam 0
fifthExam 0
sixthExam 2
.
..
.etc...
I hope that I am making sense here. I think that I need somekind of LEFT JOIN to display all of the exam name but I can not come up with the proper syntax.
It seems you want to display all name groups and, within each group, the count of Score < 0.695. So I think you should move < 0.695 from the WHERE to the Count() expression --- actually remove the WHERE clause.
SELECT
e.name,
Count(IIf(e.Score < 0.695, 1, Null)) AS CountOfName
FROM tblExam AS e
GROUP BY e.name;
That works because Count() counts only non-Null values. You could use Sum() instead of Count() if that seems clearer:
Sum(IIf(e.Score < 0.695, 1, 0)) AS CountOfName
Note DISTINCTROW is not useful in a GROUP BY query, because the grouping makes the rows unique without it. So I removed DISTINCTROW from the query.
Do I detect a contradiction? The query calls for results <0.695 but your text says you are also looking for results >0.695. Perhaps I don't understand. Does this give you what you are looking for:
SELECT DISTINCTROW tblExam.ExamName, Count(tblExam.ExamName) AS CountOfExamName
FROM tblExam
WHERE (((tblExam.Score)<0.695 Or (tblExam.Score)>0.695))
GROUP BY tblExam.ExamName;
I have to create a report using MySql DB where more than 4 tables are involved. I have one table (S1) with S1_ID and S1_Year_Range (strings like 2001-2002) and another table (S2) with S2_ID(PK), S2_Customer_ID, S1_ID (FK) and other fields for other conditions that can appear in Where clause of my query. There can be more than one row in S2 with the same S2_Customer_ID but different S1_ID. My query is to create a report using VB.net and ask users to enter two values; one number for how many continuous years or bigger (like >= 5 years), and a year range value (like 2011-2012) which is the highest value in the list for all customers.
My report lists customer names (by joining the above query with another table), customer rank and all year range values (highest at the bottom) for that customer in one column for each customer. Any help for this query would be appreciated.
Data and results could be like the following:
S1:
(S1_ID....S1_Year_Range)
(1......2000-2001)
(2......2001-2002)
(3......2002-2003)
(4......2003-2004)
(5......2004-2005)
etc
S2:
(S2_ID.....S2_Customer_ID.....S1_ID)
(1....1....1)
(2....1....2)
(3....1....3)
(4....2....2)
(5....2....3)
(6....2....5)
(7....3....2)
(8....3....3)
(9....3....4)
(10...3....5)
(11...4....3)
(12...4....4)
(13...4....5)
etc
when number 2 and year range (2003-2004) is entered by the user, the result should be the following:
customer 3 with 3 year range values (2003-2004, 2002-2003, and 2001-2002) and customer 4 with 2 year range values (2003-2004 and 2002-2003):
cname3
2001-2002
2002-2003
2003-2004
cname4
2002-2003
2003-2004
I hope you can see the columns of the report correctly.
I finally created a complex query to solve my problem. In the following query, I encoded the user year range value as '2010-2011' and number of continuous years as 14. Also a tiny difference with the question is the table names; table CSP here is the same as table S2 in my question but field names are the same as those in my question.
SELECT CSYWFY.S2_Customer_ID, COUNT(CSYWFY.S2_Customer_ID)
FROM (SELECT S1F.S1_Year_Range, S2.S2_Customer_ID , COUNT(S1F.S1_Year_Range) FROM CSP as S2 INNER JOIN S1 as S1F ON S2.S1_ID = S1F.S1_ID WHERE '2010-2011' IN (SELECT S1N.S1_Year_Range FROM CSP as S2N INNER JOIN S1 as S1N ON S2N.S1_ID = S1N.S1_ID WHERE S2N.S2_Customer_ID = S2.S2_Customer_ID ) GROUP BY S2.S2_Customer_ID ASC , S1F.S1_Year_Range DESC ) CSYWFY
GROUP BY CSYWFY.S2_Customer_ID
HAVING COUNT(CSYWFY.S2_Customer_ID) > 14
HTH