Identifiers

A SQL identifier is a name used to identify a database object, such as a catalog, database, table, view, function, or column.

Identifiers are case-insensitive.

Regular Identifiers

(letter|digit|_)+

letter is an ASCII letter (a-z or A-Z). digit is an ASCII digit (0-9).

Note that a regular identifier can start with a digit.

Delimited Identifiers

`char+`

char is a character drawn from the supported character set. The backtick character ` can be escaped by repeating it twice (i.e. ``).

Delimited identifiers are required when the identifier contains special characters. For example, SELECT * FROM a.b represents a query that selects all columns from table b in database a, while SELECT * FROM `a.b` represents a query that selects all columns from a table named a.b.