Literals

Literals play a crucial role in enhancing the accuracy of data representation and optimizing system efficiency. See the following subsections for the introduction of various types of literals.

String literals

Standard string literals

A string literal is a sequence of characters enclosed within single quotes (’). For example, 'Database' is a string literal.

To include a single-quote character within a string literal, you can use two consecutive single quotes. For example, 'Stream processing''s advantages' is a valid string literal that incorporates a single-quote character.

String literals with C-style escapes

String literals with C-style escapes use escape sequences to represent special characters within a string, just as in the C programming language. These literals are constructed by prepending the letter e to the string literal. For example, e'abc\n\tdef'.

The following escape sequences are supported:

Escape sequence	Interpretation
\b	backspace
\f	form feed
\n	newline
\r	carriage return
\t	tab
\o, \oo, \ooo (o = 0–7)	octal byte value
\xh, \xhh (h = 0–9, A–F)	hexadecimal byte value
\uXXXX (x = 0–9, A–F)	16-bit hexadecimal Unicode character value
\UXXXXXXXX (x = 0–9, A–F)	32-bit hexadecimal Unicode character value

Numeric literals

RisingWave supports expressing numeric literals in various number systems, including decimal (base 10), hexadecimal (base 16), octal (base 8), and binary (base 2). Here are some examples:

2147       -- Decimal
0x42e3     -- Hexadecimal
0o664      -- Octal
0b1101     -- Binary

Numeric literals in different bases provide you with flexibility in choosing the most suitable representation for specific needs.