Backticks vs. Single Quotes in SQL Queries

In a CodeIgniter manual excerpt, it's mentioned that the $this->db->select() method accepts an optional second parameter to disable backtick protection of field and table names. This raises three questions:

1. What are the differences between backticks (`) and single quotes (')?

Backticks quote names in MySQL, while single quotes enclose strings. Using names without backticks, like SELECT select FROM foo, will cause a syntax error because MySQL interprets it as a keyword.

2. Is it possible to use an IF statement in a query?

Yes, the IF function can be employed in SQL SELECT statements.

3. How to interpret IF(value = "", default, value) as value`?

The IF function returns the value from the default column if value is an empty string. Otherwise, it returns the value from value itself. The result will be called value.