Please use the form below to provide your feedback. Because your feedback is valuable to us, the information you submit in this form is recorded in our issue tracking system (JIRA), which is publicly available. You can track the status of your feedback using the ticket number displayed in the dialog once you submit the form.

A newer version of this documentation is available.

View Latest

Literals

  • reference
March 16, 2025
+ 12
Literal values include strings, numbers, TRUE, FALSE, NULL, and MISSING.

SQL++ supports the same literals as JSON, as defined by json.org, with these exceptions:

  • In SQL++, "true", "false," and "null" are case-insensitive to be consistent with other SQL++ keywords. In standard JSON, "true", "false," and "null" are case-sensitive.

  • "missing" is added as a literal expression, although it is not returned in final results. Missing is omitted from objects, and is converted to null in result arrays.

  • In SQL++ single and double quotation marks can be used for strings. JSON supports only double quotation marks.

Wherever a value is expected, either of two special values may appear: NULL (denoting an out-of-band value that is not comparable to any other value), and MISSING (denoting the absence of a value). Every value also has a "truth" value; these truth value conversions are explained in Boolean Logic.

Booleans

ebnf
ViewCopy
boolean ::= 'TRUE' | 'FALSE'
Syntax diagram

Boolean propositions evaluate to TRUE and FALSE. These values are case-insensitive.

Numbers

ebnf
ViewCopy
number ::= '-'? integer fraction? exponent?
Syntax diagram 
ebnf
ViewCopy
integer ::= [0-9] | [1-9] [0-9]+
Syntax diagram 
ebnf
ViewCopy
fraction ::= '.' [0-9]+
Syntax diagram 
ebnf
ViewCopy
exponent ::= ('e' | 'E') ('-' | '+')? [0-9]+
Syntax diagram

Numbers can be either signed or unsigned integers with an optional fractional component and an optional exponent. If the integer component has more than one digit, the number should not start with a leading zero.

Strings

ebnf
ViewCopy
string ::= '"' char* '"' | "'" char* "'"
Syntax diagram 
ebnf
ViewCopy
char ::= unicode-character |
         '\' ( '\' | '"' | "'" | 'b' | 'f' | 'n' | 'r' | 't' | 'u' hex hex hex hex )
Syntax diagram 
ebnf
ViewCopy
hex ::= [0-9a-fA-F]
Syntax diagram

Strings can be either Unicode characters or escaped characters.

NULL

ebnf
ViewCopy
null ::= 'NULL'
Syntax diagram

The literal NULL represents an empty value. This value is case-insensitive.

MISSING

ebnf
ViewCopy
missing ::= 'MISSING'
Syntax diagram

The MISSING literal is specific to SQL++ and represents a missing name-value pair in a document. This value is case-insensitive.