String Constants (Dollar-Quoted)

The standard syntax for specifying string constants can be difficult to understand when the desired string contains many single quotes or backslashes. To allow more readable queries in such situations, Vertica SQL provides "dollar quoting." Dollar quoting is not part of the SQL standard, but it is often a more convenient way to write complicated string literals than the standard-compliant single quote syntax. It is particularly useful when representing string constants inside other constants.

Syntax

$$characters$$

Semantics

characters is an arbitrary sequence of UTF8 characters bounded by paired dollar signs ($$).

Dollar-quoted string content is treated as a literal. Single quote, backslash, and dollar sign characters have no special meaning within a dollar-quoted string.

Notes

• A dollar-quoted string that follows a keyword or identifier must be separated from it by whitespace; otherwise the dollar quoting delimiter would be taken as part of the preceding identifier.
• The string functions not handle multibyte UTF-8 sequences correctly. They treat each byte as a character.

  WE DON'T HAVE USER-DEFINED FUNCTIONS, IS THERE ANY REASON TO DESCRIBE TAGS IN DOLLAR-QUOTED STRING CONSTANTS?

Examples

=> SELECT $$Fred's\n car$$;

?column?

-------------------

Fred's\n car

(1 row)