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Blob Functions

This section describes functions and operators for examining and manipulating BLOB values.

Function Description
arg1 || arg2 Concatenates two strings, lists, or blobs. Any NULL input results in NULL. See also concat(arg1, arg2, ...) and list_concat(list1, list2, ...).
base64(blob) Alias for to_base64.
decode(blob[, on_error]) Converts blob to VARCHAR. The optional on_error parameter controls handling of invalid UTF-8: 'strict' (default, throws error), 'replace' (replaces invalid characters with ?), or 'ignore' (removes invalid characters).
encode(string) Converts the string to BLOB. Converts UTF-8 characters into literal encoding.
from_base64(string) Converts a base64 encoded string to a character string (BLOB).
from_binary(value) Alias for unbin.
from_hex(value) Alias for unhex.
hex(blob) Converts blob to VARCHAR using hexadecimal encoding.
md5(blob) Returns the MD5 hash of the blob as a VARCHAR.
md5_number(blob) Returns the MD5 hash of the blob as a HUGEINT.
octet_length(blob) Number of bytes in blob.
read_blob(source) Returns the content from source (a filename, a list of filenames, or a glob pattern) as a BLOB. See the read_blob guide for more details.
repeat(blob, count) Repeats the blob count number of times.
sha1(blob) Returns a VARCHAR with the SHA-1 hash of the blob.
sha256(blob) Returns a VARCHAR with the SHA-256 hash of the blob.
to_base64(blob) Converts a blob to a base64 encoded string.
to_hex(blob) Alias for hex.
unbin(value) Converts a value from binary representation to a blob.
unhex(value) Converts a value from hexadecimal representation to a blob.

arg1 || arg2

Description Concatenates two strings, lists, or blobs. Any NULL input results in NULL. See also concat(arg1, arg2, ...) and list_concat(list1, list2, ...).
Example 1 'Duck' || 'DB'
Result DuckDB
Example 2 [1, 2, 3] || [4, 5, 6]
Result [1, 2, 3, 4, 5, 6]
Example 3 '\xAA'::BLOB || '\xBB'::BLOB
Result \xAA\xBB

decode(blob[, on_error])

Description Converts blob to VARCHAR. The optional on_error parameter controls handling of invalid UTF-8: 'strict' (default, throws error), 'replace' (replaces invalid characters with ?), or 'ignore' (removes invalid characters).
Example decode('\xC3\xBC'::BLOB)
Result ü
Example decode('\xAA'::BLOB, 'replace')
Result ?

encode(string)

Description Converts the string to BLOB. Converts UTF-8 characters into literal encoding.
Example encode('my_string_with_ü')
Result my_string_with_\xC3\xBC

from_base64(string)

Description Converts a base64 encoded string to a character string (BLOB).
Example from_base64('QQ==')
Result A

hex(blob)

Description Converts blob to VARCHAR using hexadecimal encoding.
Example hex('\xAA\xBB'::BLOB)
Result AABB
Alias to_hex

md5(blob)

Description Returns the MD5 hash of the blob as a VARCHAR.
Example md5('\xAA\xBB'::BLOB)
Result 58cea1f6b2b06520613e09af90dc1c47

md5_number(blob)

Description Returns the MD5 hash of the blob as a HUGEINT.
Example md5_number('\xAA\xBB'::BLOB)
Result 94525045605907259200829535064523132504

octet_length(blob)

Description Number of bytes in blob.
Example octet_length('\xAA\xBB'::BLOB)
Result 2

read_blob(source)

Description Returns the content from source (a filename, a list of filenames, or a glob pattern) as a BLOB. See the read_blob guide for more details.
Example read_blob('hello.bin')
Result hello\x0A

repeat(blob, count)

Description Repeats the blob count number of times.
Example repeat('\xAA\xBB'::BLOB, 5)
Result \xAA\xBB\xAA\xBB\xAA\xBB\xAA\xBB\xAA\xBB

sha1(blob)

Description Returns a VARCHAR with the SHA-1 hash of the blob.
Example sha1('\xAA\xBB'::BLOB)
Result 65b1e351a6cbfeb41c927222bc9ef53aad3396b0

sha256(blob)

Description Returns a VARCHAR with the SHA-256 hash of the blob.
Example sha256('\xAA\xBB'::BLOB)
Result d798d1fac6bd4bb1c11f50312760351013379a0ab6f0a8c0af8a506b96b2525a

to_base64(blob)

Description Converts a blob to a base64 encoded string.
Example to_base64('A'::BLOB)
Result QQ==
Alias base64

unbin(value)

Description Converts a value from binary representation to a blob.
Example unbin('0110')
Result \x06
Alias from_binary

unhex(value)

Description Converts a value from hexadecimal representation to a blob.
Example unhex('2A')
Result *
Alias from_hex
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