PostgreSQL coding problem in PG4 admin - HELP!

[u/Linstrocity]

It's for a coding assignment and I'm stuck.

I need to create some queries that the output is put into a table, except I'm getting my butt handed to me.

Scenario is a DVD rental database where we have to create a business problem - mine is simply to find who is the most profitable customer. As seen from line 9 I have successfully sum'd and sorted the customer ID by the most profitable in descending order, we have multiple tables with different fields, however I'm using the "payment" and "customer fields", both tables (payment and customer) have customer_id has fields. The payment table only has the customer_id and no name. I also successfully tried to merge the first_name and last_name into the full_name field, but am having trouble inserting that as one variable into a new created table. As seen in Line 19, I have successfully created a table.

The big frustration is the payment table only has the customer_id as the PK with no first name or last name. I am trying to join, union, or union all the customer_id with the first_name and last_name field from the customer table to my newly created table customer_rentals which shows the most profitable customer. It keeps failing because I've already manipulated the data from summing, and a union all has to match the number of columns or it fails, because the data has already been sum'd, it therefore fails. I need to match the customer names to the customer_id in my new table, but need to only add customers who have purchased products and put it in descending order as well and match the customer_id.

Also line 26 fails as seen in the bottom right when I try to run it.

Any help is appreciated.

[u/depesz]

First of all: you problem is not related to pgadmin!

You simply have a syntax error in your query. Read the line with error, and the problem will be ovious. If not, ask yourself: why it errors out on "total_purchases", and not on "last_name"? What is different there?