Use column name as result of SQL query

I need help about a SQL query that blow my mind. I need to use SQL to get a XML format

SQL group but return wrong result

I have a table:

Cataloging events, projects and tasks: Is SQL appropriate?

I have this idea for a database: it would hold everything I “need to remember”, and allow future coding projects to access the information. These future projects include a day-planner and historical analysis of what I’ve been up to.

Having 2 Initialize Paragraphs in 1 COBOL program

I am designing a COBOL program that does 2 things.
1 reads specific rows from a table, and inserts a new row based on the original.
2 reads different rows from the same table, and updates those rows.

Why should I add CHECK CONSTRAINT?

Following is a table creating script created by Entity Framework using the model shown in https://codereview.stackexchange.com/questions/14077/is-it-proper-tpt-inheritance.

Best method to implement a filtered search

I would like to ask you, your opinion when it comes to implement a filtered search form. Let’s imagine the following case:

How to get double output from same filename with different names [closed]

Closed last month.

Why is SQL’s BETWEEN inclusive rather than half-open?

Semi-open (or Half-Open, Half-Closed, Half-Bounded) intervals ([a,b), where xbelongs to the interval iff a <= x < b) are pretty common on programming, as they have many convenient properties.

Best way to remove list items from an existing record

Ok more of a conceptual question here:

Registration: Email hash and verifying only one account per email

I’m using a registration function that hashes the email in PBKDF2 with a random and unique Salt each time. The hashes email and his salt are saved in the DB. No problem with that.
The problem is that now I want to make sure that users only create one single account per email. Obviously to verify that I need to check my DB and that’s where the problem starts. I either lose in security or in time.