PREHOOK: query: DESCRIBE FUNCTION substr
PREHOOK: type: DESCFUNCTION
POSTHOOK: query: DESCRIBE FUNCTION substr
POSTHOOK: type: DESCFUNCTION
substr(str, pos[, len]) - returns the substring of str that starts at pos and is of length len orsubstr(bin, pos[, len]) - returns the slice of byte array that starts at pos and is of length len
PREHOOK: query: DESCRIBE FUNCTION EXTENDED substr
PREHOOK: type: DESCFUNCTION
POSTHOOK: query: DESCRIBE FUNCTION EXTENDED substr
POSTHOOK: type: DESCFUNCTION
substr(str, pos[, len]) - returns the substring of str that starts at pos and is of length len orsubstr(bin, pos[, len]) - returns the slice of byte array that starts at pos and is of length len
Synonyms: substring
pos is a 1-based index. If pos<0 the starting position is determined by counting backwards from the end of str.
Example:
   > SELECT substr('Facebook', 5) FROM src LIMIT 1;
  'book'
  > SELECT substr('Facebook', -5) FROM src LIMIT 1;
  'ebook'
  > SELECT substr('Facebook', 5, 1) FROM src LIMIT 1;
  'b'
PREHOOK: query: SELECT
  substr(null, 1), substr(null, 1, 1),
  substr('ABC', null), substr('ABC', null, 1),
  substr('ABC', 1, null)
FROM src LIMIT 1
PREHOOK: type: QUERY
PREHOOK: Input: default@src
#### A masked pattern was here ####
POSTHOOK: query: SELECT
  substr(null, 1), substr(null, 1, 1),
  substr('ABC', null), substr('ABC', null, 1),
  substr('ABC', 1, null)
FROM src LIMIT 1
POSTHOOK: type: QUERY
POSTHOOK: Input: default@src
#### A masked pattern was here ####
NULL	NULL	NULL	NULL	NULL
PREHOOK: query: SELECT
  substr('ABC', 1, 0), substr('ABC', 1, -1), substr('ABC', 2, -100),
  substr('ABC', 4), substr('ABC', 4, 100),
  substr('ABC', -4), substr('ABC', -4, 100),
  substr('ABC', 100), substr('ABC', 100, 100),
  substr('ABC', -100), substr('ABC', -100, 100),
  substr('ABC', 2147483647), substr('ABC', 2147483647, 2147483647)
FROM src LIMIT 1
PREHOOK: type: QUERY
PREHOOK: Input: default@src
#### A masked pattern was here ####
POSTHOOK: query: SELECT
  substr('ABC', 1, 0), substr('ABC', 1, -1), substr('ABC', 2, -100),
  substr('ABC', 4), substr('ABC', 4, 100),
  substr('ABC', -4), substr('ABC', -4, 100),
  substr('ABC', 100), substr('ABC', 100, 100),
  substr('ABC', -100), substr('ABC', -100, 100),
  substr('ABC', 2147483647), substr('ABC', 2147483647, 2147483647)
FROM src LIMIT 1
POSTHOOK: type: QUERY
POSTHOOK: Input: default@src
#### A masked pattern was here ####
												
PREHOOK: query: SELECT
  substr('ABCDEFG', 3, 4), substr('ABCDEFG', -5, 4),
  substr('ABCDEFG', 3), substr('ABCDEFG', -5),
  substr('ABC', 0), substr('ABC', 1), substr('ABC', 2), substr('ABC', 3),
  substr('ABC', 1, 2147483647), substr('ABC', 2, 2147483647),
  substr('A', 0), substr('A', 1), substr('A', -1)
FROM src LIMIT 1
PREHOOK: type: QUERY
PREHOOK: Input: default@src
#### A masked pattern was here ####
POSTHOOK: query: SELECT
  substr('ABCDEFG', 3, 4), substr('ABCDEFG', -5, 4),
  substr('ABCDEFG', 3), substr('ABCDEFG', -5),
  substr('ABC', 0), substr('ABC', 1), substr('ABC', 2), substr('ABC', 3),
  substr('ABC', 1, 2147483647), substr('ABC', 2, 2147483647),
  substr('A', 0), substr('A', 1), substr('A', -1)
FROM src LIMIT 1
POSTHOOK: type: QUERY
POSTHOOK: Input: default@src
#### A masked pattern was here ####
CDEF	CDEF	CDEFG	CDEFG	ABC	ABC	BC	C	ABC	BC	A	A	A
PREHOOK: query: SELECT
  substr('ABC', 0, 1), substr('ABC', 0, 2), substr('ABC', 0, 3), substr('ABC', 0, 4),
  substr('ABC', 1, 1), substr('ABC', 1, 2), substr('ABC', 1, 3), substr('ABC', 1, 4),
  substr('ABC', 2, 1), substr('ABC', 2, 2), substr('ABC', 2, 3), substr('ABC', 2, 4),
  substr('ABC', 3, 1), substr('ABC', 3, 2), substr('ABC', 3, 3), substr('ABC', 3, 4),
  substr('ABC', 4, 1)
FROM src LIMIT 1
PREHOOK: type: QUERY
PREHOOK: Input: default@src
#### A masked pattern was here ####
POSTHOOK: query: SELECT
  substr('ABC', 0, 1), substr('ABC', 0, 2), substr('ABC', 0, 3), substr('ABC', 0, 4),
  substr('ABC', 1, 1), substr('ABC', 1, 2), substr('ABC', 1, 3), substr('ABC', 1, 4),
  substr('ABC', 2, 1), substr('ABC', 2, 2), substr('ABC', 2, 3), substr('ABC', 2, 4),
  substr('ABC', 3, 1), substr('ABC', 3, 2), substr('ABC', 3, 3), substr('ABC', 3, 4),
  substr('ABC', 4, 1)
FROM src LIMIT 1
POSTHOOK: type: QUERY
POSTHOOK: Input: default@src
#### A masked pattern was here ####
A	AB	ABC	ABC	A	AB	ABC	ABC	B	BC	BC	BC	C	C	C	C	
PREHOOK: query: SELECT
  substr('ABC', -1, 1), substr('ABC', -1, 2), substr('ABC', -1, 3), substr('ABC', -1, 4),
  substr('ABC', -2, 1), substr('ABC', -2, 2), substr('ABC', -2, 3), substr('ABC', -2, 4),
  substr('ABC', -3, 1), substr('ABC', -3, 2), substr('ABC', -3, 3), substr('ABC', -3, 4),
  substr('ABC', -4, 1)
FROM src LIMIT 1
PREHOOK: type: QUERY
PREHOOK: Input: default@src
#### A masked pattern was here ####
POSTHOOK: query: SELECT
  substr('ABC', -1, 1), substr('ABC', -1, 2), substr('ABC', -1, 3), substr('ABC', -1, 4),
  substr('ABC', -2, 1), substr('ABC', -2, 2), substr('ABC', -2, 3), substr('ABC', -2, 4),
  substr('ABC', -3, 1), substr('ABC', -3, 2), substr('ABC', -3, 3), substr('ABC', -3, 4),
  substr('ABC', -4, 1)
FROM src LIMIT 1
POSTHOOK: type: QUERY
POSTHOOK: Input: default@src
#### A masked pattern was here ####
C	C	C	C	B	BC	BC	BC	A	AB	ABC	ABC	
PREHOOK: query: -- substring() is a synonim of substr(), so just perform some basic tests
SELECT
  substring('ABCDEFG', 3, 4), substring('ABCDEFG', -5, 4),
  substring('ABCDEFG', 3), substring('ABCDEFG', -5),
  substring('ABC', 0), substring('ABC', 1), substring('ABC', 2), substring('ABC', 3),
  substring('ABC', 1, 2147483647), substring('ABC', 2, 2147483647),
  substring('A', 0), substring('A', 1), substring('A', -1)
FROM src LIMIT 1
PREHOOK: type: QUERY
PREHOOK: Input: default@src
#### A masked pattern was here ####
POSTHOOK: query: -- substring() is a synonim of substr(), so just perform some basic tests
SELECT
  substring('ABCDEFG', 3, 4), substring('ABCDEFG', -5, 4),
  substring('ABCDEFG', 3), substring('ABCDEFG', -5),
  substring('ABC', 0), substring('ABC', 1), substring('ABC', 2), substring('ABC', 3),
  substring('ABC', 1, 2147483647), substring('ABC', 2, 2147483647),
  substring('A', 0), substring('A', 1), substring('A', -1)
FROM src LIMIT 1
POSTHOOK: type: QUERY
POSTHOOK: Input: default@src
#### A masked pattern was here ####
CDEF	CDEF	CDEFG	CDEFG	ABC	ABC	BC	C	ABC	BC	A	A	A
PREHOOK: query: -- test for binary substr
SELECT
  substr(null, 1), substr(null, 1, 1),
  substr(ABC, null), substr(ABC, null, 1),
  substr(ABC, 1, null),
  substr(ABC, 0, 1), substr(ABC, 0, 2), substr(ABC, 0, 3), substr(ABC, 0, 4),
  substr(ABC, 1, 1), substr(ABC, 1, 2), substr(ABC, 1, 3), substr(ABC, 1, 4),
  substr(ABC, 2, 1), substr(ABC, 2, 2), substr(ABC, 2, 3), substr(ABC, 2, 4),
  substr(ABC, 3, 1), substr(ABC, 3, 2), substr(ABC, 3, 3), substr(ABC, 3, 4),
  substr(ABC, 4, 1),
  substr(ABC, -1, 1), substr(ABC, -1, 2), substr(ABC, -1, 3), substr(ABC, -1, 4),
  substr(ABC, -2, 1), substr(ABC, -2, 2), substr(ABC, -2, 3), substr(ABC, -2, 4),
  substr(ABC, -3, 1), substr(ABC, -3, 2), substr(ABC, -3, 3), substr(ABC, -3, 4),
  substr(ABC, -4, 1)
FROM (
   select CAST(concat(substr(value, 1, 0), 'ABC') as BINARY) as ABC from src LIMIT 1
) X
PREHOOK: type: QUERY
PREHOOK: Input: default@src
#### A masked pattern was here ####
POSTHOOK: query: -- test for binary substr
SELECT
  substr(null, 1), substr(null, 1, 1),
  substr(ABC, null), substr(ABC, null, 1),
  substr(ABC, 1, null),
  substr(ABC, 0, 1), substr(ABC, 0, 2), substr(ABC, 0, 3), substr(ABC, 0, 4),
  substr(ABC, 1, 1), substr(ABC, 1, 2), substr(ABC, 1, 3), substr(ABC, 1, 4),
  substr(ABC, 2, 1), substr(ABC, 2, 2), substr(ABC, 2, 3), substr(ABC, 2, 4),
  substr(ABC, 3, 1), substr(ABC, 3, 2), substr(ABC, 3, 3), substr(ABC, 3, 4),
  substr(ABC, 4, 1),
  substr(ABC, -1, 1), substr(ABC, -1, 2), substr(ABC, -1, 3), substr(ABC, -1, 4),
  substr(ABC, -2, 1), substr(ABC, -2, 2), substr(ABC, -2, 3), substr(ABC, -2, 4),
  substr(ABC, -3, 1), substr(ABC, -3, 2), substr(ABC, -3, 3), substr(ABC, -3, 4),
  substr(ABC, -4, 1)
FROM (
   select CAST(concat(substr(value, 1, 0), 'ABC') as BINARY) as ABC from src LIMIT 1
) X
POSTHOOK: type: QUERY
POSTHOOK: Input: default@src
#### A masked pattern was here ####
NULL	NULL	null	null	null	A	AB	ABC	ABC	A	AB	ABC	ABC	B	BC	BC	BC	C	C	C	C		C	C	C	C	B	BC	BC	BC	A	AB	ABC	ABC	
PREHOOK: query: -- test UTF-8 substr
SELECT
  substr("玩", 1),
  substr("abc 玩", 5),
  substr("abc 玩玩玩 abc", 5),
  substr("abc 玩玩玩 abc", 5, 3)
FROM src LIMIT 1
PREHOOK: type: QUERY
PREHOOK: Input: default@src
#### A masked pattern was here ####
POSTHOOK: query: -- test UTF-8 substr
SELECT
  substr("玩", 1),
  substr("abc 玩", 5),
  substr("abc 玩玩玩 abc", 5),
  substr("abc 玩玩玩 abc", 5, 3)
FROM src LIMIT 1
POSTHOOK: type: QUERY
POSTHOOK: Input: default@src
#### A masked pattern was here ####
玩	玩	玩玩玩 abc	玩玩玩