ENCODE

Encode binary data into a SQL expression of type TEXT.

Syntax

ENCODE(<expression>, <format>)

Parameters

Parameter	Description	Supported input types
<expression>	A SQL expression of type BYTEA	BYTEA
<format>	Format to use to encode binary data	HEX, ESCAPE, BASE64 (case insensitive)

The HEX format represents each 4 bits of data as one hexadecimal digit, 0 through f, writing the higher-order digit of each byte first. The ENCODE function outputs the a-f hex digits in lower case. Because the smallest unit of data is 8 bits, there are always an even number of characters returned by ENCODE.

The ESCAPE format converts zero bytes and bytes with the high bit set into octal escape sequences (\nnn) and doubles backslashes. Other byte values are represented literally.

THE BASE64 format, per RFC 2045 Secion 6.8, breaks encoded lines at 76 characters using a newline for end of line.

Return Type

TEXT

Example

The following examples encode binary expressions to the ESCAPE, HEX, and BASE64 format:

SELECT
	ENCODE('123\000456'::BYTEA, 'ESCAPE');

Returns: 123\000456

SELECT
	ENCODE('123\000456'::BYTEA, 'HEX');

Returns: 31323300343536

SELECT
	ENCODE('123\000456'::BYTEA, 'BASE64');

Returns: MTIzADQ1Ng==