Literals

Literals#

Literals are numbers or strings used in SQL as constants. Literals are included in the select-list, along with expressions and built-in functions and can also be constants.

Querona provides support for number-type literals (integers, numerics, money), string literals, VARBINARY string literals, and date/time literals. The various string literal formats are discussed in this section.

Number-type Literals#

Syntax#

*digits*
*digits*.[*digits*]_ | [*digits*].*digits*
*digits*__e__[+-]*digits* | [*digits*].*digits***e**[+-]*digits* | *digits*.[*digits*]**e**[+-]*digits*
[+-]$[+-]*digits* | [+-]$[+-]*digits* | [+-]$[+-]*digits*.[*digits*] | [+-]$[+-][*digits*].*digits*

Parameters#

Name

Description

digits

Represents one or more numeric characters (0 through 9).

e

Represents an exponent marker.

$

Represents a money symbol

Notes#

  • In most cases a numeric-type constant is automatically coerced to the most appropriate type depending on context. When necessary, you can force a numeric value to be interpreted as a specific data type by casting

  • It is allowed to have multiple subsequent positive/negative symbols.

Examples#

select 3123
     , 22.
     , .09
     , 11e9
     , 11e+9
     , 11e-9
     , 4.e-10
     , 0000123456789e

Money-typed values:

select $120.90
     , $.90
     , $1.
     , $-90.90
     , $+.0808

String Literals#

String literals are string values surrounded by single quotes. Single-quoted strings do not require a backslash, except for ‘ and \.

You can embed single quotes, backslashes and another backslash (escape) sequences, such as \t (tab), into strings.

Character String Literals#

Character string literals are a sequence of characters from a predefined character set and are enclosed by single quotes. If the single quote is part of the sequence, it must be doubled as “’’”.

Syntax#

‘characters’

Parameters#

characters Arbitrary sequence of characters bounded by single quotes (‘)

Unicode String Literals

Syntax#

N’characters’

Parameters#

characters Arbitrary sequence of UTF-8 characters bounded by single quotes (‘)

VARBINARY String Literals#

VARBINARY string literals allow you to specify hexadecimal digits in a string literal.

Syntax#

0x’hexadecimal_digits’

Parameters#

hexadecimal_digits Specifies hexadecimal digits.

Date/Time Literals#

Date or time literal input must be enclosed in single quotes or curly braces. Input is accepted in almost any reasonable format, including ISO 8601, SQL-compatible, ODBC, and others.

Querona handles date/time input more flexibly than the SQL standard requires. The exact parsing rules of date/time input and for the recognized text fields including months, and days of the week are described in Date/Time Expressions.

Time Zone Values#

Querona currently does not support date and time with time zones definitions.