Major Description
According to the SQL standard:
<interval literal> ::=
INTERVAL [ <sign> ] <interval string> <interval qualifier>
<interval string> ::=
<quote> <unquoted interval string> <quote>
<unquoted interval string> ::=
[ <sign> ] { <year-month literal> | <day-time literal> }
<sign> ::=
<plus sign>
| <minus sign>
but the parsing fails:
spark-sql> select interval -'1-1' year to month; Error in query: mismatched input 'to' expecting {<EOF>, ';'}(line 1, pos 28) == SQL == select interval -'1-1' year to month ----------------------------^^^
