Returning results for the whole of yesterday and not the last 24 hours - sql

Question

I have this query that needs data for yesterday. What i have below returns result for the last 24 hours which is different from yesterday 00.00 - 23.59.
Here is what i have but doesn't solve the problem.
Select * from message where now() - arrival_timestamp <= interval '24 hour'

Answer 1

You could cast the timestamp to date with the syntax expression::type (more info on The Type Casts section of The PostgreSQL Documentation). Sufficient tools for making the comparison between dates can be found from the section 9.9. Date/Time Functions and Operators:
SELECT * FROM message WHERE arrival_timestamp::date = current_date - 1;
If you have an index on arrival_timestamp the cast to date would render the index unusable in the query. In that case use other comparison operators:
SELECT * FROM message WHERE arrival_timestamp >= current_date - 1 AND arrival_timestamp < current_date;

Answer 2

You might try this:
SELECT * FROM message
WHERE date_trunc('day', arrival_timestamp) = current_date - interval '1 day'

Answer 3

When working with time or any other data type, you want to avoid a filter criteria in the form
function( field ) comparison other_field_or_constant
This is non-sargable. What that means is that the optimizer can't take advantage if field is indexed. Since it cannot predict what value will result from the function call, it must perform a complete table scan and submit every field value to the function to make the comparison.
So you want every expression in the where clause to be in the form
field comparison other_field_or_constant
Note that function( constant ) is still a constant as all such results are cached and re-used for each comparison rather than the function being called for each comparison.
In your case, here, in pseudo-code, is what you want to do. You want yesterday. Fine, every DBMS I know has a system function that returns Now. Yesterday is from midnight the day before Now right up to but not including midnight of Now.
where arrival_timestamp >= trunc( now ) - 1 day
and arrival_timestamp < trunc( now );
Translating the expression above to English is: "where the value is on or after midnight yesterday morning and any time up to but not including midnight last nite." In other words, "yesterday." Performing the comparison this way, you don't have to worry about how close to midnight the system clock can generate a timestamp. As soon as the time clicks to midnight last nite, no matter how large or extremely small that click may be, the comparison yields a valid result.
Notice, no manipulation is performed on arrival_timestamp, not even to convert it to a more convenient data type. The expression trunc( now ) (including the one where a day is subtracted) is a constant. The functions are called once and the result used over and over for every row. This is why all such functions must be deterministic. Even functions that are NOT in fact deterministic, like Now, are deemed to be deterministic for the life of the query.
For that reason you can do pretty much whatever you need to do on the right side of the comparison. For example, because SQL Server doesn't have a trunc function, the first line written above would look like this:
where arrival_timestamp >= DateAdd( day, -1, DateAdd( day, DateDiff( day, 0, GetDate()), 0))
It doesn't matter. The calculation is performed once and the result used for the entire duration of the query.
So the where clause can now be seen as
where field >= constant1
and field < constant2;
This means if field is indexed, that index can now be used.

Answer 4

you can use the DATE_PART function
select * from message where DATE_PART('day', now() - arrival_timestamp) <= 1