Add convenience alias byteSlice for substring

docs/en/sql-reference/functions/bit-functions.md

@@ -167,6 +167,10 @@ Result:
 └──────────────────────────────────────────┴───────────────────────────────┘
 ```
 
+## byteSlice(s, offset, length)
+
+See function [substring](string-functions.md#substring).
+
 ## bitTest
 
 Takes any integer and converts it into [binary form](https://en.wikipedia.org/wiki/Binary_number), returns the value of a bit at specified position. The countdown starts from 0 from the right to the left.

docs/en/sql-reference/functions/string-functions.md

@@ -558,6 +558,7 @@ substring(s, offset[, length])
 Alias:
 - `substr`
 - `mid`
+- `byteSlice`
 
 **Arguments**
 

src/Functions/substring.cpp

@@ -189,6 +189,7 @@ REGISTER_FUNCTION(Substring)
     factory.registerFunction<FunctionSubstring<false>>({}, FunctionFactory::CaseInsensitive);
     factory.registerAlias("substr", "substring", FunctionFactory::CaseInsensitive); // MySQL alias
     factory.registerAlias("mid", "substring", FunctionFactory::CaseInsensitive); /// MySQL alias
+    factory.registerAlias("byteSlice", "substring", FunctionFactory::CaseInsensitive); /// resembles PostgreSQL's get_byte function, similar to ClickHouse's bitSlice
 
     factory.registerFunction<FunctionSubstring<true>>({}, FunctionFactory::CaseSensitive);
 }

tests/queries/0_stateless/01033_function_substring.reference

@@ -170,4 +170,6 @@ g
 
 
 
-UBSAN bug
+-- UBSAN bug
+-- Alias
+el

tests/queries/0_stateless/01033_function_substring.sql

@@ -132,7 +132,7 @@ SELECT substring(s, l, r) FROM t;
 
 DROP table if exists t;
 
-SELECT 'UBSAN bug';
+SELECT '-- UBSAN bug';l
 
 /** NOTE: The behaviour of substring and substringUTF8 is inconsistent when negative offset is greater than string size:
   * substring:
@@ -144,3 +144,6 @@ SELECT 'UBSAN bug';
   * This may be subject for change.
   */
 SELECT substringUTF8('hello, пÑ<C2BF>ивеÑ<C2B5>', -9223372036854775808, number) FROM numbers(16) FORMAT Null;
+
+SELECT '-- Alias';
+SELECT byteSlice('hello', 2, 2);