If N is 1, the ELT function returns string1 and if N is 2, it returns string2. The return value is a VARCHAR type. You can add conditional expressions as needed.
The maximum length of the character string is 33,554,432 and if this length is exceeded, NULL will be returned.
If N is 0 or a negative number, an empty string will be returned. If N is greater than the number of this input character string, NULL will be returned as it is out of range. If N is a type that can not be converted to an integer, an error will be returned.
ELT(N, string1, string2, ... )
string :
• character string
• NULL
SELECT ELT(3,'string1','string2','string3');
elt(3, 'string1', 'string2', 'string3')
======================
'string3'
SELECT ELT('3','1/1/1','23:00:00','2001-03-04');
elt('3', '1/1/1', '23:00:00', '2001-03-04')
======================
'2001-03-04'
SELECT ELT(-1, 'string1','string2','string3');
elt(-1, 'string1','string2','string3')
======================
NULL
SELECT ELT(4,'string1','string2','string3');
elt(4, 'string1', 'string2', 'string3')
======================
NULL
SELECT ELT(3.2,'string1','string2','string3');
elt(3.2, 'string1', 'string2', 'string3')
======================
'string3'
SELECT ELT('a','string1','string2','string3');
ERROR: Cannot coerce value of domain "character" to domain "bigint".