SELECT '-- argument validation'; SELECT substring('hello', []); -- { serverError ILLEGAL_TYPE_OF_ARGUMENT } SELECT substring('hello', 1, []); -- { serverError ILLEGAL_TYPE_OF_ARGUMENT } SELECT substring(materialize('hello'), -1, -1); SELECT substring(materialize('hello'), 0); -- { serverError ZERO_ARRAY_OR_TUPLE_INDEX } SELECT '-- FixedString arguments'; SELECT substring(toFixedString('hello', 16), 1, 8); SELECT substring(toFixedString(materialize('hello'), 16), 1, 8); SELECT substring(toFixedString(toString(number), 16), 1, 8) FROM system.numbers LIMIT 10; SELECT substring(toFixedString(toString(number), 4), 1, 3) FROM system.numbers LIMIT 995, 10; SELECT substring(toFixedString(toString(number), 4), 1, number % 5) FROM system.numbers LIMIT 995, 10; SELECT substring(toFixedString(toString(number), 4), 1 + number % 5) FROM system.numbers LIMIT 995, 10; SELECT substring(toFixedString(toString(number), 4), 1 + number % 5, 1 + number % 3) FROM system.numbers LIMIT 995, 10; SELECT '-- Enum arguments'; DROP TABLE IF EXISTS tab; CREATE TABLE tab(e8 Enum8('hello' = -5, 'world' = 15), e16 Enum16('shark' = -999, 'eagle' = 9999)) ENGINE MergeTree ORDER BY tuple(); INSERT INTO TABLE tab VALUES ('hello', 'shark'), ('world', 'eagle'); -- positive offsets (slice from left) SELECT substring(e8, 1), substring (e16, 1) FROM tab; SELECT substring(e8, 2, 10), substring (e16, 2, 10) FROM tab; -- negative offsets (slice from right) SELECT substring(e8, -1), substring (e16, -1) FROM tab; SELECT substring(e8, -2, 10), substring (e16, -2, 10) FROM tab; -- zero offset/length SELECT substring(e8, 1, 0), substring (e16, 1, 0) FROM tab; SELECT '-- Constant enums'; SELECT substring(CAST('foo', 'Enum8(\'foo\' = 1)'), 1, 1), substring(CAST('foo', 'Enum16(\'foo\' = 1111)'), 1, 2); DROP TABLE tab; SELECT '-- negative offset argument'; SELECT substring('abc', number - 5) FROM system.numbers LIMIT 10; SELECT substring(materialize('abc'), number - 5) FROM system.numbers LIMIT 10; SELECT substring(toFixedString('abc', 3), number - 5) FROM system.numbers LIMIT 10; SELECT substring(materialize(toFixedString('abc', 3)), number - 5) FROM system.numbers LIMIT 10; SELECT substring('clickhouse', 2, -2); SELECT substring(materialize('clickhouse'), 2, -2); SELECT substring('clickhouse', materialize(2), -2); SELECT substring(materialize('clickhouse'), materialize(2), -2); SELECT substring('clickhouse', 2, materialize(-2)); SELECT substring(materialize('clickhouse'), 2, materialize(-2)); SELECT substring('clickhouse', materialize(2), materialize(-2)); SELECT substring(materialize('clickhouse'), materialize(2), materialize(-2)); SELECT '-- negative length argument'; SELECT substring('abcdefgh', 2, -2); SELECT substring('abcdefgh', materialize(2), -2); SELECT substring('abcdefgh', 2, materialize(-2)); SELECT substring('abcdefgh', materialize(2), materialize(-2)); SELECT substring(cast('abcdefgh' AS FixedString(8)), 2, -2); SELECT substring(cast('abcdefgh' AS FixedString(8)), materialize(2), -2); SELECT substring(cast('abcdefgh' AS FixedString(8)), 2, materialize(-2)); SELECT substring(cast('abcdefgh' AS FixedString(8)), materialize(2), materialize(-2)); DROP TABLE IF EXISTS tab; CREATE TABLE tab (s String, l Int8, r Int8) ENGINE = Memory; INSERT INTO tab VALUES ('abcdefgh', 2, -2), ('12345678', 3, -3); SELECT substring(s, 2, -2) FROM tab; SELECT substring(s, l, -2) FROM tab; SELECT substring(s, 2, r) FROM tab; SELECT substring(s, l, r) FROM tab; DROP TABLE IF EXISTS tab; CREATE TABLE tab (s FixedString(8), l Int8, r Int8) ENGINE = Memory; INSERT INTO tab VALUES ('abcdefgh', 2, -2), ('12345678', 3, -3); SELECT substring(s, 2, -2) FROM tab; SELECT substring(s, l, -2) FROM tab; SELECT substring(s, 2, r) FROM tab; SELECT substring(s, l, r) FROM tab; DROP TABLE IF EXISTS tab; SELECT '-- negative offset and size'; SELECT substring('abcdefgh', -2, -2); SELECT substring(materialize('abcdefgh'), -2, -2); SELECT substring(materialize('abcdefgh'), materialize(-2), materialize(-2)); SELECT substring('abcdefgh', -2, -1); SELECT substring(materialize('abcdefgh'), -2, -1); SELECT substring(materialize('abcdefgh'), materialize(-2), materialize(-1)); SELECT substring(cast('abcdefgh' AS FixedString(8)), -2, -2); SELECT substring(materialize(cast('abcdefgh' AS FixedString(8))), -2, -2); SELECT substring(materialize(cast('abcdefgh' AS FixedString(8))), materialize(-2), materialize(-2)); SELECT substring(cast('abcdefgh' AS FixedString(8)), -2, -1); SELECT substring(materialize(cast('abcdefgh' AS FixedString(8))), -2, -1); SELECT substring(materialize(cast('abcdefgh' AS FixedString(8))), materialize(-2), materialize(-1)); DROP TABLE IF EXISTS t; CREATE TABLE t ( s String, l Int8, r Int8 ) ENGINE = Memory; INSERT INTO t VALUES ('abcdefgh', -2, -2),('12345678', -3, -3); SELECT substring(s, -2, -2) FROM t; SELECT substring(s, l, -2) FROM t; SELECT substring(s, -2, r) FROM t; SELECT substring(s, l, r) FROM t; SELECT '-'; DROP TABLE IF EXISTS t; CREATE TABLE t( s FixedString(8), l Int8, r Int8 ) engine = Memory; INSERT INTO t VALUES ('abcdefgh', -2, -2),('12345678', -3, -3); SELECT substring(s, -2, -2) FROM t; SELECT substring(s, l, -2) FROM t; SELECT substring(s, -2, r) FROM t; SELECT substring(s, l, r) FROM t; DROP table if exists t; SELECT 'UBSAN bug'; /** NOTE: The behaviour of substring and substringUTF8 is inconsistent when negative offset is greater than string size: * substring: * hello * ^-----^ - offset -10, length 7, result: "he" * substringUTF8: * hello * ^-----^ - offset -10, length 7, result: "hello" * This may be subject for change. */ SELECT substringUTF8('hello, п�иве�', -9223372036854775808, number) FROM numbers(16) FORMAT Null;