Identifiers

Identifiers (names) of objects such as schema, table, projection, column names, and so on.

Unquoted Identifiers

Unquoted SQL identifiers must begin with one of the following:

  • Letters (use A–Z or a-z only)
  • Underscore ( _ )

Subsequent characters in an identifier can be:

  • Letters (as above)
  • Unicode letters (letters with diacriticals or not in the Latin alphabet)
  • Underscore ( _ )
  • Digits (0–9)
  • Dollar sign ($)
  • Hash sign (#)
  • Percent sign (%)
  • At symbol (@)

Quoted Identifiers

Identifiers enclosed in a double quote (“) or square bracket ([ and ]) characters can contain any character. If you want to include a double quote (or a bracket), you need a pair of them; for example “”””. You can use names that would otherwise be invalid, such as names that include only numeric characters (“123”) or contain space characters, punctuation marks, keywords, and so on; for example:

CREATE TABLE "my table!" (col1 int);

Delimiters are required for non-alphanumerics and SQL keywords such as “1time”, “Next week” and “Select”.

Note

Identifiers are not case-sensitive. Thus, identifiers “ABC”, “ABc”, and “aBc” are synonymous, as are ABC, ABc, and aBc.