TRIM ( [ [ LEADING | TRAILING | BOTH ] [ trim_string ] FROM ] string )
trim_string :
• character string
• NULL
string :
• character string literal
• string valued column
• NULL
--trimming NULL returns NULL
SELECT TRIM (NULL);
trim(both from null)
======================
NULL
--trimming spaces on both leading and trailing parts
SELECT TRIM (' Olympic ');
trim(both from ' Olympic ')
======================
'Olympic'
--trimming specific strings on both leading and trailing parts
SELECT TRIM ('i' FROM 'iiiiiOlympiciiiii');
trim(both 'i' from 'iiiiiOlympiciiiii')
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'Olympic'
--trimming specific strings on the leading part
SELECT TRIM (LEADING 'i' FROM 'iiiiiOlympiciiiii');
trim(leading 'i' from 'iiiiiOlympiciiiii')
======================
'Olympiciiiii'
--trimming specific strings on the trailing part
SELECT TRIM (TRAILING 'i' FROM 'iiiiiOlympiciiiii');
trim(trailing 'i' from 'iiiiiOlympiciiiii')
======================
'iiiiiOlympic'