Re: Search content within a bytea field

Damiano Bolzoni <damiano(dot)bolzoni(at)gmail(dot)com> writes:
> But...why if I manually query with a SQL client (AquaStudio) as
> follows:

> SELECT myfield FROM mytable WHERE myfield LIKE '%hello%'

> and 'myfield' is a bytea field I get the result I expected?

The unknown-type literal is assumed to be of type bytea in this case.
In general, if the parser finds "known_type_value operator unmarked_literal"
then it preferentially selects an operator with both input types the
same, ie, it prefers to believe the unmarked_literal is the same data
type as the other input.

The JDBC environment behaves differently because setString and so on
do not produce unmarked literals --- there's an implicit cast to
some datatype. So you have to make sure you've picked a
parameter-setting function that is reasonably compatible with the
intended operation. This is a good thing, really; it tends to keep
the system from choosing an unexpected operation.

regards, tom lane