I’ve two tables with these structures: Table 1 (comments) Table 2 (posts) My goal is to get a list with the latest comment from each post of a specific category_id. So for example, if I have category 1 as input I need the comments with the id 2 and 1 because these are always the last comments for each p…
Tag: mysql
How does a prioritization query work (one value is preferred over another if a criteria is met)
DB-Fiddle The table displays different campaigns and their status within the purchasing process using event_types. The process is as the following: Based on this structure the result should look like this: In order to achieve this I go with the prioritization query described in the question here: This query g…
Mysql Left join index
I used the following query To display items from two tables, where the id of the first table is the item_id of the second. My question is , when I try to display this in php , if I want to display a.id i can try with: or since both tables have id,on the first example displays only if there
Only display values of latest available event type
SQL Fiddle: In the table above the purchasing process for different campaigns is displayed using an Event_Type and a Quantity that applies to the Event_Type. Every campaign can only have each Event_Type once. Now, I want ot get the Quantity of the latest available status within the purchasing process for each…
Get the average of values in every specific epoch ranges in unix timestamp which returns -1 in specific condition in MySQL
I have a MySQL table which has some records as follows: I want to compute the average for every 10 epochs to see the following results: I saw some similar answers like enter link description here and enter link description here and enter link description here but these answers are not a solution for my specif…
Laravel 6 many to many relationship
In laravel 6, I have 2 models I have third model to join tables Now how can I get all the teachers those are not subscribed by a particular student? For example: Teacher1, Teacher2, Teacher3, Teacher4 are in the Teacher table and Student1, Student2, Student3, Student4 are in the Student table Student1 subscri…
Copy result of select statement into a local database table
I would like to copy the contents of a remote DB query into a local database table. What would be the best way to do this? Currently I’m trying something like: The first part of the command works fine to grab the data — the second part I’ve just added as a sort of pseudo-code to show what I&…
MySQL select complete last month
How to select all data from last month (or 30 days)? I already found some answers, and mostly gives this solution But this gives me also the dates from the future I am only interested in the days from last month or 30 days (not next month and beyond) Answer Is this what you want? I added a condition so
Get aggregated average values joining three tables and display them next to each value in first table
I have three tables which you can also find in the SQL fiddle: CREATE TABLE Sales ( Product_ID VARCHAR(255), Sales_Value VARCHAR(255), Sales_Quantity VARCHAR(255) ); INSERT INTO Sales (…
mySQL Self Join – inner join or join
quick clarification. When joining contents from the same table, must I always declare join type as INNER? For example, (on the table shown in this screenshot) When I tried to remove the keyword INNER, it was wrong. Is it because JOIN does not exist in SQL? Thanks and cheers. Answer You do want a self (inner) …