字符串函数

CRC32(s)

SELECT CRC32('ClickHouse')

┌─CRC32('ClickHouse')─┐
│          1538217360 │
└─────────────────────┘

CRC32IEEE(s)

SELECT CRC32IEEE('ClickHouse');

┌─CRC32IEEE('ClickHouse')─┐
│              3089448422 │
└─────────────────────────┘

CRC64(s)

SELECT CRC64('ClickHouse');

┌──CRC64('ClickHouse')─┐
│ 12126588151325169346 │
└──────────────────────┘

appendTrailingCharIfAbsent(s, c)

SELECT appendTrailingCharIfAbsent('https://example.com', '/');

┌─appendTrailingCharIfAbsent('https://example.com', '/')─┐
│ https://example.com/                                   │
└────────────────────────────────────────────────────────┘

ascii(s)

SELECT ascii('234')

┌─ascii('234')─┐
│           50 │
└──────────────┘

base32Decode(encoded)

SELECT base32Decode('IVXGG33EMVSA====');

┌─base32Decode('IVXGG33EMVSA====')─┐
│ Encoded                          │
└──────────────────────────────────┘

base32Encode(plaintext)

SELECT base32Encode('Encoded')

┌─base32Encode('Encoded')─┐
│ IVXGG33EMVSA====        │
└─────────────────────────┘

base58Decode(encoded[, expected_size])

SELECT base58Decode('JxF12TrwUP45BMd');

┌─base58Decode('JxF12TrwUP45BMd')─┐
│ Hello World                     │
└─────────────────────────────────┘

base58Encode(plaintext)

SELECT base58Encode('ClickHouse');

┌─base58Encode('ClickHouse')─┐
│ 4nhk8K7GHXf6zx             │
└────────────────────────────┘

base64Decode(encoded)

SELECT base64Decode('Y2xpY2tob3VzZQ==')

┌─base64Decode('Y2xpY2tob3VzZQ==')─┐
│ clickhouse                       │
└──────────────────────────────────┘

base64Encode(plaintext)

SELECT base64Encode('clickhouse')

┌─base64Encode('clickhouse')─┐
│ Y2xpY2tob3VzZQ==           │
└────────────────────────────┘

base64URLDecode(encoded)

SELECT base64URLDecode('aHR0cHM6Ly9jbGlja2hvdXNlLmNvbQ')

┌─base64URLDecode('aHR0cHM6Ly9jbGlja2hvdXNlLmNvbQ')─┐
│ https://clickhouse.com                            │
└───────────────────────────────────────────────────┘

base64URLEncode(plaintext)

SELECT base64URLEncode('https://clickhouse.com')

┌─base64URLEncode('https://clickhouse.com')─┐
│ aHR0cHM6Ly9jbGlja2hvdXNlLmNvbQ            │
└───────────────────────────────────────────┘

basename(expr)

SELECT 'some/long/path/to/file' AS a, basename(a)

┌─a──────────────────────┬─basename(a)─┐
│ some/long/path/to/file │ file        │
└────────────────────────┴─────────────┘

SELECT 'some\\long\\path\\to\\file' AS a, basename(a)

┌─a──────────────────────┬─basename(a)─┐
│ some\long\path\to\file │ file        │
└────────────────────────┴─────────────┘

SELECT 'some-file-name' AS a, basename(a)

┌─a──────────────┬─basename(a)────┐
│ some-file-name │ some-file-name │
└────────────────┴────────────────┘

byteHammingDistance(s1, s2)

SELECT byteHammingDistance('karolin', 'kathrin')

┌─byteHammingDistance('karolin', 'kathrin')─┐
│                                         3 │
└───────────────────────────────────────────┘

caseFoldUTF8(str)

SELECT caseFoldUTF8('Straße')

┌─caseFoldUTF8('Straße')─┐
│ strasse                │
└────────────────────────┘

compareSubstrings(s1, s2, s1_offset, s2_offset, num_bytes)

SELECT compareSubstrings('Saxony', 'Anglo-Saxon', 0, 6, 5) AS result

┌─result─┐
│      0 │
└────────┘

concat([s1, s2, ...])

SELECT concat('Hello, ', 'World!')

┌─concat('Hello, ', 'World!')─┐
│ Hello, World!               │
└─────────────────────────────┘

SELECT concat(42, 144)

┌─concat(42, 144)─┐
│ 42144           │
└─────────────────┘

concatAssumeInjective([s1, s2, ...])

CREATE TABLE key_val (key1 String, key2 String, value UInt32) ENGINE = Memory;
INSERT INTO key_val VALUES ('Hello, ', 'World!', 1), ('Hello, ', 'World!', 2), ('Hello, ', 'World', 3);

SELECT concatAssumeInjective(key1, key2) AS key, sum(value) FROM key_val GROUP BY key ORDER BY key;

┌─key───────────┬─sum(value)─┐
│ Hello, World  │          3 │
│ Hello, World! │          3 │
└───────────────┴────────────┘

concatWithSeparator(sep[, exp1, exp2, ...])

SELECT concatWithSeparator('a', '1', '2', '3', '4')

┌─concatWithSeparator('a', '1', '2', '3', '4')─┐
│ 1a2a3a4                                      │
└──────────────────────────────────────────────┘

concatWithSeparatorAssumeInjective(sep[, exp1, exp2, ... ])

CREATE TABLE user_data (
user_id UInt32,
first_name String,
last_name String,
score UInt32
)
ENGINE = MergeTree
ORDER BY tuple();

INSERT INTO user_data VALUES
(1, 'John', 'Doe', 100),
(2, 'Jane', 'Smith', 150),
(3, 'John', 'Wilson', 120),
(4, 'Jane', 'Smith', 90);

SELECT
    concatWithSeparatorAssumeInjective('-', first_name, last_name) as full_name,
    sum(score) as total_score
FROM user_data
GROUP BY concatWithSeparatorAssumeInjective('-', first_name, last_name);

┌─full_name───┬─total_score─┐
│ Jane-Smith  │         240 │
│ John-Doe    │         100 │
│ John-Wilson │         120 │
└─────────────┴─────────────┘

conv(number, from_base, to_base)

SELECT conv('10', 10, 2)

1010

SELECT conv('FF', 16, 10)

255

SELECT conv('-1', 10, 16)

FFFFFFFFFFFFFFFF

SELECT conv('1010', 2, 8)

12

convertCharset(s, from, to)

SELECT convertCharset('Café', 'UTF-8', 'ISO-8859-1');

┌─convertCharset('Café', 'UTF-8', 'ISO-8859-1')─┐
│ Caf�                                           │
└───────────────────────────────────────────────┘

damerauLevenshteinDistance(s1, s2)

SELECT damerauLevenshteinDistance('clickhouse', 'mouse')

┌─damerauLevenshteinDistance('clickhouse', 'mouse')─┐
│                                                 6 │
└───────────────────────────────────────────────────┘

decodeHTMLComponent(s)

SELECT decodeHTMLComponent('<div>Hello & "World"</div>')

┌─decodeHTMLComponent('<div>Hello & "World"</div>')─┐
│ <div>Hello & "World"</div>                                                  │
└─────────────────────────────────────────────────────────────────────────────┘

decodeXMLComponent(s)

SELECT decodeXMLComponent('<tag>Hello & World</tag>')

┌─decodeXMLComponent('<tag>Hello & World</tag>')─┐
│ <tag>Hello & World</tag>                                       │
└────────────────────────────────────────────────────────────────┘

editDistance(s1, s2)

SELECT editDistance('clickhouse', 'mouse')

┌─editDistance('clickhouse', 'mouse')─┐
│                                   6 │
└─────────────────────────────────────┘

editDistanceUTF8(s1, s2)

SELECT editDistanceUTF8('我是谁', '我是我') AS distance

┌─distance─┐
│        1 │
└──────────┘

encodeXMLComponent(s)

SELECT
    '<tag>Hello & "World"</tag>' AS original,
    encodeXMLComponent('<tag>Hello & "World"</tag>') AS xml_encoded;

┌─original───────────────────┬─xml_encoded──────────────────────────────────────────┐
│ <tag>Hello & "World"</tag> │ &lt;tag&gt;Hello &amp; &quot;World&quot;&lt;/tag&gt; │
└────────────────────────────┴──────────────────────────────────────────────────────┘

endsWith(s, suffix)

SELECT endsWith('ClickHouse', 'House');

┌─endsWith('ClickHouse', 'House')─┐
│                               1 │
└─────────────────────────────────┘

endsWithCaseInsensitive(s, suffix)

SELECT endsWithCaseInsensitive('ClickHouse', 'HOUSE');

┌─endsWithCaseInsensitive('ClickHouse', 'HOUSE')─┐
│                                              1 │
└────────────────────────────────────────────────┘

endsWithCaseInsensitiveUTF8(s, suffix)

SELECT endsWithCaseInsensitiveUTF8('данных', 'ых');

┌─endsWithCaseInsensitiveUTF8('данных', 'ых')─┐
│                                           1 │
└─────────────────────────────────────────────┘

endsWithUTF8(s, suffix)

SELECT endsWithUTF8('данных', 'ых');

┌─endsWithUTF8('данных', 'ых')─┐
│                            1 │
└──────────────────────────────┘

extractTextFromHTML(html)

SELECT extractTextFromHTML('
<html>
    <head><title>Page Title</title></head>
    <body>
        <p>Hello <b>World</b>!</p>
        <script>alert("test");</script>
        <!-- comment -->
    </body>
</html>
');

┌─extractTextFromHTML('\n<html>\n    <head><title>Page Title</title></head>\n    <body>\n        <p>Hello <b>World</b>!</p>\n        <script>alert("test");</script>\n        <!-- comment -->\n    </body>\n</html>\n')─┐
│ Page Title Hello World !                                                                                                                                                                                               │
└────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘

firstLine(s)

SELECT firstLine('foo\\nbar\\nbaz')

┌─firstLine('foo\\nbar\\nbaz')─┐
│ foo\nbar\nbaz                │
└──────────────────────────────┘

idnaDecode(s)

SELECT idnaDecode('xn--strae-oqa.xn--mnchen-3ya.de')

┌─idnaDecode('xn--strae-oqa.xn--mnchen-3ya.de')─┐
│ straße.münchen.de                             │
└───────────────────────────────────────────────┘

idnaEncode(s)

SELECT idnaEncode('straße.münchen.de')

┌─idnaEncode('straße.münchen.de')─┐
│ xn--strae-oqa.xn--mnchen-3ya.de │
└─────────────────────────────────┘

initcap(s)

SELECT initcap('building for fast')

┌─initcap('building for fast')─┐
│ Building For Fast            │
└──────────────────────────────┘

SELECT initcap('John''s cat won''t eat.');

┌─initcap('John\'s cat won\'t eat.')─┐
│ John'S Cat Won'T Eat.              │
└────────────────────────────────────┘

initcapUTF8(s)

SELECT initcapUTF8('не тормозит')

┌─initcapUTF8('не тормозит')─┐
│ Не Тормозит                │
└────────────────────────────┘

isValidASCII(str)

SELECT isValidASCII('hello') AS is_ascii, isValidASCII('你好') AS is_not_ascii

┌─is_ascii─┬─is_not_ascii─┐
│        1 │            0 │
└──────────┴──────────────┘

isValidUTF8(s)

SELECT isValidUTF8('\\xc3\\xb1') AS valid, isValidUTF8('\\xc3\\x28') AS invalid

┌─valid─┬─invalid─┐
│     1 │       1 │
└───────┴─────────┘

jaroSimilarity(s1, s2)

SELECT jaroSimilarity('clickhouse', 'click')

┌─jaroSimilarity('clickhouse', 'click')─┐
│                    0.8333333333333333 │
└───────────────────────────────────────┘

jaroWinklerSimilarity(s1, s2)

SELECT jaroWinklerSimilarity('clickhouse', 'click')

┌─jaroWinklerSimilarity('clickhouse', 'click')─┐
│                           0.8999999999999999 │
└──────────────────────────────────────────────┘

left(s, offset)

SELECT left('Hello World', 5)

Hello

SELECT left('Hello World', -6)

Hello

leftPad(string, length[, pad_string])

SELECT leftPad('abc', 7, '*'), leftPad('def', 7)

┌─leftPad('abc', 7, '*')─┬─leftPad('def', 7)─┐
│ ****abc                │     def           │
└────────────────────────┴───────────────────┘

leftPadUTF8(string, length[, pad_string])

SELECT leftPadUTF8('абвг', 7, '*'), leftPadUTF8('дежз', 7)

┌─leftPadUTF8('абвг', 7, '*')─┬─leftPadUTF8('дежз', 7)─┐
│ ***абвг                     │    дежз                │
└─────────────────────────────┴────────────────────────┘

leftUTF8(s, offset)

SELECT leftUTF8('Привет', 4)

Прив

SELECT leftUTF8('Привет', -4)

Пр

lengthUTF8(s)

SELECT lengthUTF8('Здравствуй, мир!')

┌─lengthUTF8('Здравствуй, мир!')─┐
│                             16 │
└────────────────────────────────┘

lower(s)

SELECT lower('CLICKHOUSE')

┌─lower('CLICKHOUSE')─┐
│ clickhouse          │
└─────────────────────┘

lowerUTF8(input)

SELECT lowerUTF8('München') as Lowerutf8;

münchen

naturalSortKey(s)

CREATE TABLE t (s String) ENGINE = Memory;
INSERT INTO t VALUES ('a1'), ('a02');

SELECT s FROM t ORDER BY naturalSortKey(s);

┌─s───┐
│ a1  │
│ a02 │
└─────┘

normalizeUTF8NFC(str)

SELECT
'é' AS original, -- e + 组合尖音符 (U+0065 + U+0301)
length(original),
normalizeUTF8NFC('é') AS nfc_normalized, -- é (U+00E9)
length(nfc_normalized);

┌─original─┬─length(original)─┬─nfc_normalized─┬─length(nfc_normalized)─┐
│ é        │                2 │ é              │                      2 │
└──────────┴──────────────────┴────────────────┴────────────────────────┘

normalizeUTF8NFD(str)

SELECT
    'é' AS original, -- é (U+00E9)
    length(original),
    normalizeUTF8NFD('é') AS nfd_normalized, -- e + 组合重音符（U+0065 + U+0301）
    length(nfd_normalized);

┌─original─┬─length(original)─┬─nfd_normalized─┬─length(nfd_normalized)─┐
│ é        │                2 │ é              │                      3 │
└──────────┴──────────────────┴────────────────┴────────────────────────┘

normalizeUTF8NFKC(str)

SELECT
    '① ② ③' AS original,                           -- Circled number characters
    normalizeUTF8NFKC('① ② ③') AS nfkc_normalized  -- Converts to 1 2 3

┌─original─┬─nfkc_normalized─┐
│ ① ② ③    │ 1 2 3           │
└──────────┴─────────────────┘

normalizeUTF8NFKCCasefold(str)

SELECT
    'Ä ① Hello' AS original,
    normalizeUTF8NFKCCasefold('Ä ① Hello') AS nfkc_cf_normalized;

┌─original──┬─nfkc_cf_normalized─┐
│ Ä ① Hello │ ä 1 hello          │
└───────────┴────────────────────┘

normalizeUTF8NFKD(str)

SELECT
    'H₂O²' AS original,                           -- H + subscript 2 + O + superscript 2
    normalizeUTF8NFKD('H₂O²') AS nfkd_normalized  -- Converts to H 2 O 2

┌─original─┬─nfkd_normalized─┐
│ H₂O²     │ H2O2            │
└──────────┴─────────────────┘

punycodeDecode(s)

SELECT punycodeDecode('Mnchen-3ya')

┌─punycodeDecode('Mnchen-3ya')─┐
│ München                      │
└──────────────────────────────┘

punycodeEncode(s)

SELECT punycodeEncode('München')

┌─punycodeEncode('München')─┐
│ Mnchen-3ya                │
└───────────────────────────┘

regexpExtract(haystack, pattern[, index])

SELECT
    regexpExtract('100-200', '(\\d+)-(\\d+)', 1),
    regexpExtract('100-200', '(\\d+)-(\\d+)', 2),
    regexpExtract('100-200', '(\\d+)-(\\d+)', 0),
    regexpExtract('100-200', '(\\d+)-(\\d+)'),
    regexpExtract('100-200', '\\d+');

┌─regexpExtract('100-200', '(\\d+)-(\\d+)', 1)─┬─regexpExtract('100-200', '(\\d+)-(\\d+)', 2)─┬─regexpExtract('100-200', '(\\d+)-(\\d+)', 0)─┬─regexpExtract('100-200', '(\\d+)-(\\d+)')─┬─regexpExtract('100-200', '\\d+')─┐
│ 100                                          │ 200                                          │ 100-200                                      │ 100                                       │ 100                              │
└──────────────────────────────────────────────┴──────────────────────────────────────────────┴──────────────────────────────────────────────┴───────────────────────────────────────────┴──────────────────────────────────┘

regexpPosition(haystack, pattern[, position[, occurrence[, return_option[, flags[, subexpression]]]]])

SELECT
    regexpPosition('hello world', 'world'),
    regexpPosition('aXbXcXd', 'X', 1, 2),
    regexpPosition('aXbXcXd', 'X', 1, 2, 1),
    regexpPosition('Hello WORLD', 'world', 1, 1, 0, 'i'),
    regexpPosition('foo123bar456', '([a-z]+)([0-9]+)', 1, 2, 0, '', 2);

┌─regexpPosition('hello world', 'world')─┬─regexpPosition('aXbXcXd', 'X', 1, 2)─┬─regexpPosition('aXbXcXd', 'X', 1, 2, 1)─┬─regexpPosition('Hello WORLD', 'world', 1, 1, 0, 'i')─┬─regexpPosition('foo123bar456', '([a-z]+)([0-9]+)', 1, 2, 0, '', 2)─┐
│                                      7 │                                    4 │                                       5 │                                                    7 │                                                                 10 │
└────────────────────────────────────────┴──────────────────────────────────────┴─────────────────────────────────────────┴──────────────────────────────────────────────────────┴────────────────────────────────────────────────────────────────────┘

removeDiacriticsUTF8(str)

SELECT removeDiacriticsUTF8('café résumé naïve')

┌─removeDiacriticsUTF8('café résumé naïve')─┐
│ cafe resume naive                         │
└───────────────────────────────────────────┘

repeat(s, n)

SELECT repeat('abc', 10)

┌─repeat('abc', 10)──────────────┐
│ abcabcabcabcabcabcabcabcabcabc │
└────────────────────────────────┘

reverseUTF8(s)

SELECT reverseUTF8('ClickHouse')

esuoHkcilC

right(s, offset)

SELECT right('Hello', 3)

llo

SELECT right('Hello', -3)

lo

rightPad(string, length[, pad_string])

SELECT rightPad('abc', 7, '*'), rightPad('abc', 7)

┌─rightPad('abc', 7, '*')─┬─rightPad('abc', 7)─┐
│ abc****                 │ abc                │
└─────────────────────────┴────────────────────┘

rightPadUTF8(string, length[, pad_string])

SELECT rightPadUTF8('абвг', 7, '*'), rightPadUTF8('абвг', 7)

┌─rightPadUTF8('абвг', 7, '*')─┬─rightPadUTF8('абвг', 7)─┐
│ абвг***                      │ абвг                    │
└──────────────────────────────┴─────────────────────────┘

rightUTF8(s, offset)

SELECT rightUTF8('Привет', 4)

ивет

SELECT rightUTF8('Привет', -4)

ет

soundex(s)

SELECT soundex('aksel')

┌─soundex('aksel')─┐
│ A240             │
└──────────────────┘

space(n)

SELECT space(3) AS res, length(res);

┌─res─┬─length(res)─┐
│     │           3 │
└─────┴─────────────┘

sparseGrams(s[, min_ngram_length[, max_ngram_length[, min_cutoff_length]]])

SELECT sparseGrams('alice', 3)

┌─sparseGrams('alice', 3)────┐
│ ['ali','lic','ice','lice'] │
└────────────────────────────┘

sparseGramsHashes(s[, min_ngram_length, max_ngram_length])

SELECT sparseGramsHashes('alice', 3)

┌─sparseGramsHashes('alice', 3)────────────────┐
│ [3851133533,3120039944,646693941,2577359366] │
└──────────────────────────────────────────────┘

sparseGramsHashesUTF8(s[, min_ngram_length, max_ngram_length])

SELECT sparseGramsHashesUTF8('алиса', 3)

┌─sparseGramsHashesUTF8('алиса', 3)───────────────────────┐
│ [1328958118,547287748,4155892324,2403052185,1673399070] │
└─────────────────────────────────────────────────────────┘

sparseGramsUTF8(s[, min_ngram_length[, max_ngram_length[, min_cutoff_length]]])

SELECT sparseGramsUTF8('алиса', 3)

┌─sparseGramsUTF8('алиса', 3)────────┐
│ ['али','лис','иса','лиса','алиса'] │
└────────────────────────────────────┘

startsWith(s, prefix)

SELECT startsWith('ClickHouse', 'Click');

┌─startsWith('ClickHouse', 'Click')─┐
│                                 1 │
└───────────────────────────────────┘

startsWithCaseInsensitive(s, prefix)

SELECT startsWithCaseInsensitive('ClickHouse', 'CLICK');

┌─startsWithCaseInsensitive('ClickHouse', 'CLICK')─┐
│                                                1 │
└──────────────────────────────────────────────────┘

startsWithCaseInsensitiveUTF8(s, prefix)

SELECT startsWithCaseInsensitiveUTF8('приставка', 'при')

┌─startsWithCaseInsensitiveUTF8('приставка', 'при')─┐
│                                                 1 │
└───────────────────────────────────────────────────┘

startsWithUTF8(s, prefix)

SELECT startsWithUTF8('приставка', 'при')

┌─startsWithUTF8('приставка', 'при')─┐
│                                  1 │
└────────────────────────────────────┘

stringBytesEntropy(s)

SELECT stringBytesEntropy('Hello, world!')

┌─stringBytesEntropy('Hello, world!')─┐
│                   3.180832987205441 │
└─────────────────────────────────────┘

stringBytesUniq(s)

SELECT stringBytesUniq('Hello')

┌─stringBytesUniq('Hello')─┐
│                        4 │
└──────────────────────────┘

stringJaccardIndex(s1, s2)

SELECT stringJaccardIndex('clickhouse', 'mouse')

┌─stringJaccardIndex('clickhouse', 'mouse')─┐
│                                       0.4 │
└───────────────────────────────────────────┘

stringJaccardIndexUTF8(s1, s2)

SELECT stringJaccardIndexUTF8('我爱你', '我也爱你') AS jaccard_index

┌─jaccard_index─┐
│          0.75 │
└───────────────┘

substring(s, offset[, length])

SELECT 'database' AS db, substr(db, 5), substr(db, 5, 1)

┌─db───────┬─substr(db, 5)─┬─substr(db, 5, 1)─┐
│ database │ base          │ b                │
└──────────┴───────────────┴──────────────────┘

substringIndex(s, delim, count)

SELECT substringIndex('www.clickhouse.com', '.', 2)

┌─substringIndex('www.clickhouse.com', '.', 2)─┐
│ www.clickhouse                               │
└──────────────────────────────────────────────┘

substringIndexUTF8(s, delim, count)

SELECT substringIndexUTF8('www.straßen-in-europa.de', '.', 2)

www.straßen-in-europa

substringUTF8(s, offset[, length])

SELECT 'Täglich grüßt das Murmeltier.' AS str, substringUTF8(str, 9), substringUTF8(str, 9, 5)

Täglich grüßt das Murmeltier.	grüßt das Murmeltier.	grüßt

toValidUTF8(s)

SELECT toValidUTF8('\\x61\\xF0\\x80\\x80\\x80b')

\\x61\\xF0\\x80\\x80\\x80b

trimBoth(s[, trim_characters])

SELECT trimBoth('$$ClickHouse$$', '$')

┌─trimBoth('$$ClickHouse$$', '$')─┐
│ ClickHouse                      │
└─────────────────────────────────┘

trimLeft(input[, trim_characters])

SELECT trimLeft('ClickHouse', 'Click');

┌─trimLeft('ClickHouse', 'Click')─┐
│ House                           │
└─────────────────────────────────┘

trimRight(s[, trim_characters])

SELECT trimRight('ClickHouse','House');

┌─trimRight('ClickHouse', 'House')─┐
│ Click                            │
└──────────────────────────────────┘

tryBase32Decode(encoded)

SELECT tryBase32Decode('IVXGG33EMVSA====');

┌─tryBase32Decode('IVXGG33EMVSA====')─┐
│ Encoded                             │
└─────────────────────────────────────┘

tryBase58Decode(encoded[, expected_size])

SELECT tryBase58Decode('3dc8KtHrwM') AS res, tryBase58Decode('invalid') AS res_invalid;

┌─res─────┬─res_invalid─┐
│ Encoded │             │
└─────────┴─────────────┘

tryBase64Decode(encoded)

SELECT tryBase64Decode('Y2xpY2tob3VzZQ==')

┌─tryBase64Decode('Y2xpY2tob3VzZQ==')─┐
│ clickhouse                          │
└─────────────────────────────────────┘

tryBase64URLDecode(encoded)

SELECT tryBase64URLDecode('aHR0cHM6Ly9jbGlja2hvdXNlLmNvbQ')

┌─tryBase64URLDecode('aHR0cHM6Ly9jbGlja2hvdXNlLmNvbQ')─┐
│ https://clickhouse.com                               │
└──────────────────────────────────────────────────────┘

tryIdnaEncode(s)

SELECT tryIdnaEncode('straße.münchen.de')

┌─tryIdnaEncode('straße.münchen.de')─┐
│ xn--strae-oqa.xn--mnchen-3ya.de    │
└────────────────────────────────────┘

tryPunycodeDecode(s)

SELECT tryPunycodeDecode('Mnchen-3ya')

┌─tryPunycodeDecode('Mnchen-3ya')─┐
│ München                         │
└─────────────────────────────────┘

upper(s)

SELECT upper('clickhouse')

┌─upper('clickhouse')─┐
│ CLICKHOUSE          │
└─────────────────────┘

upperUTF8(s)

SELECT upperUTF8('München') AS Upperutf8

┌─Upperutf8─┐
│ MÜNCHEN   │
└───────────┘