I'm sure you know this, LanX, but, for those who might not, I've gotta nitpick: Placeholders do not
escape metacharacters. When using placeholders, the placeholder values are sent to the database completely separately from the query structure, which removes any need for escaping of any characters - data cannot be confused for commands because the data and the commands are not sent together.
I know this seems like an academic distinction, but I consider it an important one because referring to placeholders as a way of escaping metacharacters encourages people to think of escaping and placeholders as equivalent, so, if placeholders are inconvenient, then, meh, escaping is just as good - which is false. They are not equivalent. Proper escaping can provide excellent protection against injection attacks, but placeholders provide absolute protection.
(There is one exception to this: Database backends which don't actually support placeholders, so the DBD layer has to fake it by using escaping internally. But it's still better to use placeholders in such cases, both for compatibility with databases which do support real placeholders and because the person who wrote the database driver probably knows more than you do about what's needed to properly escape data for that particular backend.)