Skip to content

Tag: join

Count rows after joining three tables in PostgreSQL

Suppose I have three tables in PostgreSQL: Suppose I am using the using the following query: I get 50 as count. Whereas with: I get only 25 as count. What is my mistake in the second query? What can I do to get the same count? My requirement is that there is a single user table, referenced by multiple tables.

How to retrieve count of records in SELECT statement

I am trying to retrieve the right count of records to mitigate an issue I am having. The below query returns 327 records from my database: Where I run into trouble is trying to reconcile that with the below query. One is for showing just a count of all the particular students the other is showing pertinent in…

MySQL Query join last comment to topic

I have a topic and topic_comments table. I want to join them both. The join is on topic.id = topic_comments.parent_id. I want to show the topic with latest comment and order by latest comment createdate. And not show duplicate topics. Can anyone help me? So far I have this: This however doesn ‘t show to…

Select info from a table referencing info from another table

I have a main product table with different products. Different products have different specs, so I’ve created separate specs tables for each product (there will be more than ten of them). What I want to do is to show individual product’s specs on a product_page.php whenever the product is clicked.…

inflation calculation in MS SQL

I have the below requirement to fulfill. How to achieve this simplistically. There is an inflation rate table as below I need to first get And then get Answer I think the best way to do this on SQLserver is to use a common table expression with recursion. I’m not 100% sure because I can’t test it …

Counting number of joined rows in left join

I’m trying to write an aggregate query in SQL which returns the count of all records joined to a given record in a table; If no records were joined to the given record, then the result for that record should be 0: Data My database looks like this (I’m not able to change the structure, unfortunatel…