The MySQL documentation you cite actually says a little bit more than you mention. It also says,
'” inside a string quoted with “
'” may be written as “
(Also, you linked to the MySQL 5.0 version of Table 8.1. Special Character Escape Sequences, and the current version is 5.6 — but the current Table 8.1. Special Character Escape Sequences looks pretty similar.)
I think the Postgres note on the
backslash_quote (string) parameter is informative:
This controls whether a quote mark can be represented by
\'in a string literal. The preferred, SQL-standard way to represent a quote mark is by doubling it (
'') but PostgreSQL has historically also accepted
\'. However, use of
\'creates security risks…
That says to me that using a doubled single-quote character is a better overall and long-term choice than using a backslash to escape the single-quote.
Now if you also want to add choice of language, choice of SQL database and its non-standard quirks, and choice of query framework to the equation, then you might end up with a different choice. You don’t give much information about your constraints.