You can use multiline comments in SQL to add longer comments across multiple lines. To add multiline comments, enclose your text between/*and*/. The SQL interpreter will ignore any text enclosed between/*and*/. /* This query retrieves the employee number, first name, last name, and gende...
To follow along with the examples used in this guide, imagine that you run an at-home dog care service. You decide to use an SQL database to store information about each dog you’ve signed up for the service, as well as each of the dog care professionals your service employs. To keep...
In order to bring the proper clarity and to make the code readable, comments are added to the code. Comments are added by the developer or the programmer of the code to make it understandable for everyone. We also usually use comments in the psql so that the queries and commands are more...
but doing so is technically only necessary in operations where two columns from different tables share the same name. It’s good practice to use them when working with multiple tables, though, as they can help makeJOINoperations easier to read and understand. ...
In the following section, you learn how to create, update and delete view objects in your MySQL database.Create a SQL View To create a new view object, you use the CREATE VIEW statement followed by the desired name of the object and the SELECT statement used for abstraction. Here, you ...
Basic Commenting in PostgreSQL To comment on anything in a Postgres query, use the following syntax for your code. -- [comment string] (STANDARD SQL SINGLE LINE) or /* [comment string comment string 2] */ (STANDARD SQL MULTI LINE CODE) Comments are removed before further syntax analysis ...
When executing an entity query (e.g. JPQL, HQL or Criteria API), you can use any SQL function without having to register it as long as the function is passed directly to the WHERE clause of the underlying SQL statement. However, if the SQL function is used in the SELECT clause, and ...
In this post, we are going to understand what the COALESCE function is and how to use it in PostgreSQL. What is a COALESCE Function? COALESCE is a system in-built function that can be considered one of the conditional expressions available in PostgreSQL. NULLIF, GREATEST, LEAST, and COALESCE...
I have to write an update query. If the special_member account is not canceled then in the where clause I have to use this condition by adding a grace period of 15 to the expiry date and compare it today's date: Convert(date,MEMBER_EXPIRY_DATE + 15)…
Hello Folks, I have an issue to use Multi-Valued Subqueries in my select statement. I want to assign a value for each row but it obviously rejects it because my subquery returns multiple values. It failed to run with this error: Subquery returned more…