Keep trailing zeros on Timestamp SELECT

Question

This is the issue: I am reading rows with a timestamp column from a table and I need to make sure that the database returns the timestamp with a fixed width. But I am encountering instances where the PostgreSQL database returns the timestamp without the trailing zeros.

The table I am working on contains UUID, Varchar, Smallint and Timestamp. I understand that I can use "to_char" as explained here, but what I am really looking for is a way tell PostgreSQL to always return the Timestamp in a given format, regardless of zeros.

Here is an example of the output from the Timestamp column I get, which contains a trimmed Timestamp:

"2014-09-26 17:17:45.999"
"2014-11-26 17:17:46"
"2015-03-26 17:17:46.001"
"2015-04-26 17:17:46.002"
"2015-05-26 17:17:46.003"

This will naturally cause a problem for me since the function that is reading from the database expects to get a timestamp in a given format.

Is there a way to make the PostgreSQL always return a timestamp with a fixed width on SELECT * FROM [table] queries?

Below you see how the fields are created:

"created_UTC" timestamp NOT NULL DEFAULT (now() AT TIME ZONE 'UTC'),
"last_modified_UTC" timestamp NOT NULL DEFAULT (now() AT TIME ZONE 'UTC')

Answer 1

It seems to me that you need to set the Timestamp column to CURRENT_TIMESTAMP(3). This would set the column to return the time to the three digit precision you are looking for.

Answer 2

After some back and forth, I managed to figure what was actually going on and how to fix it.

the function that is reading from the database expects to get a timestamp in a given format To me this means that the given function expect these to be text parameters, not timestamps. It would otherwise be content with the timestamp... – dezso Jan 27 at 20:22

This was helpful because it lead to me to understand that if you ask the JDBC for PostgreSQL to return a Timestamp as String, it will automatically trim the zeroes at the end.

Example:

ResultSet rs = {get rows from database}
rs.getString(TIMESTAMP_COLUMN);

will return a potentially shortened (trimmed) string with the last zeroes removed.
While:

ResultSet rs = {get rows from database}
rs.getTimestamp(TIMESTAMP_COLUMN);

will actually return a Java Timestamp object, with no trimming issues.

This is unexpected behavior and I'm not sure what the reasoning behind trimming strings can be, but I have at least figured out where the issue is and how to fix it.

Many thanks for the assistance. Huzzah!