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select '2018-06-22T02: 00: 00.000' as source_value,
to_date(substr('2018-06-22T02: 00: 00.000', 0, instr('2018-06-22T02: 00: 00.000', '.')-1), 'YYYY-MM-DD"T"hh24: mi: ss')converted_value from dual;
| SOURCE_VALUE | CONVERTED_VALUE |
|---|---|
| 2018-06-22T02: 00: 00.000 | 22-JUN-18 |