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Tag: count

How to count number of groups?

I have a table as follow: I want to count the number of distinct g_n. (Here it’s 3.) I have tried with: But it gives me the number of items per group. How can I count the number of distinct g_n? Answer Use count(distinct): There is no need to aggregate using group by for this result. Note: This ignores NULL

Anyway to add a constraint when using SQL count

I want to to use count to include a criteria where patient doesn’t have diabetetes, and then using the query to show country that has at least 3 patients that doesn’t have diabetes How shoudl I be doing this? How can I include a constraint when using count? yeah I think this should work, basically my logic is not every

right way to get sum of all the counts done in sql

This is my query, I want to get how many numbers of phones call received today as one column, so how do I do a sum using count function? If I do a sum, that would just return the total sum? how do I return the total numbers of all calls received today, I would do count uniquecallerID and then

SQL Select from many-to-one

I have two tables containing a one-to-many relationship. How should I select the “one” side given information for the “many” side? I’m using SQLite. Let’s say our first table, T1, is about cars and the second table, T2, is about the imperfections in each car. Let’s say we can describe the imperfections with an integer. So we have: We have

SQL query using Sum() and count() functions

I’m trying to query in PostgresQL using the SUM function to get the total of 3 different row types (Root, Dynamic, Test). I used the Sum() function for the first attempt and the Count() function for the second attempt; both didn’t work sadly. I expect a syntax error (since I’m a beginner at using SQL), but I’m not sure what

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