What is Ad Hoc Query?

Question

Recently, I'm reading a book about SQL.

In that book, I can't understand this term - Ad Hoc Query.

I want to know what is exactly means "Ad Hoc Query"

Help me, please.

Thanks in advance.

Answer 1

Ad hoc is latin for "for this purpose". You might call it an "on the fly" query, or a "just so" query. It's the kind of SQL query you just loosely type out where you need it

var newSqlQuery = "SELECT * FROM table WHERE id = " + myId;

...which is an entirely different query each time that line of code is executed, depending on the value of myId. The opposite of an ad hoc query is a predefined query such as a Stored Procedure, where you have created a single query for the entire generalized purpose of selecting from that table (say), and pass the ID as a variable.