I tried researching about this but couldn't find any answer probably because I don't really know how to tell what I'm looking for properly. I am using JDBC driver of Java to create a PreparedStatement for Postgresql. I have a…
Does MySQL have any aliasing capabilities for column/table names without specifying them in the query? For example, Let's pretend I have a very complex application talking to an equally complex schema that's been touched by many hands over the years.…
I have these tables here: and I want to query the store ID with the most purchases in a specific month (any month). I came up with this query: SELECT DISTINCT store_id FROM (SELECT store_id, purchase_date FROM purchase where purchase_date…
I have the following table members: ID hobby 1 Football 1 Tennis 1 Football 2 Cards 2 Painting 3 Tennis 3 Football 4 Cards and i want to select pairs of members only if they have the exact same hobbies…
I have table with classification result of binary classification. something like id, predict_value, real_value 1, true, true 2, true, false ... I want to get with sql classification_report, something like class precision recall f1-score support False 0.97 1.00 0.98 57241…
I'm stuck with a plpgsql syntax error. Here is the error message : ERROR: syntax error on or near "LANGUAGE" LINE 30: LANGUAGE plpgsql; I solved a previous syntax error and after I changed my code I got a new…
In my database, I have table wp_postmeta, example: | meta_key | meta_value | post_id | --------------------------------- points | 12 | 23 points | 2 | 18 lorem | ipsum | 92 points | 8 | 15 I want to order…
Context I have two tables entity_a and entity_b. The entity_b is linked to entity_a through a foreign key, and has another field date, which is a date (not a datetime, not a timestamp). The date field of entity_b indicates when…
I have a digital Meter. This digital Meter puts it's metering Data into a (Postgres) Database. The relevant Data looks like this: timestamp, total_m3 Every few seconds to minutes, I get the Data logged into the Database. So every 15…
I have a table named 'species' with 3 columns: id, specie, rate. And I have tried using the following query but it throws the errors: Fatal error: Uncaught Error: Call to a member function insert() on null in D:Wordpress....includesspecie_form.php on…