Why use prepared statements instead of Query / Exec with go sql package?

Question

In the go sql package, I understand that each statement should be closed after execution. Why would someone use prepared statements instead of just the raw Query or Exec methods?

Answer 1

I think the best answer comes from the wikipedia article on Prepared Statements.

Quoting:

The overhead of compiling and optimizing the statement is incurred only once, although the statement is executed multiple times. Not all optimization can be performed at the time the prepared statement is compiled, for two reasons: the best plan may depend on the specific values of the parameters, and the best plan may change as tables and indexes change over time.

Prepared statements are resilient against SQL injection, because parameter values, which are transmitted later using a different protocol, need not be correctly escaped. If the original statement template is not derived from external input, SQL injection cannot occur.