Oracle comparing timestamp with date

Question

I have a timestamp field and I just want to compare the date part of it in my query in Oracle

How do I do that,

SELECT * FROM Table1 WHERE date(field1) = '2012-01-01'  

Answer 1

You can truncate the date part:

select * from table1 where trunc(field1) = to_date('2012-01-01', 'YYYY-MM-DD') 

The trouble with this approach is that any index on field1 wouldn't be used due to the function call.

Alternatively (and more index friendly)

select * from table1   where field1 >= to_timestamp('2012-01-01', 'YYYY-MM-DD')     and field1 < to_timestamp('2012-01-02', 'YYYY-MM-DD') 

Answer 2

You can truncate the date

SELECT * FROM Table1 WHERE trunc(field1) = to_Date('2012-01-01','YYY-MM-DD') 

Look at the SQL Fiddle for more examples.