David G. Johnston <david.g.johns...@gmail.com> wrote: > On Mon, May 18, 2015 at 3:31 PM, Bruno Harbulot > <br...@distributedmatter.net>wrote:
>> In the discussion on the OpenJDK JDBC list two years ago >> ( >> http://mail.openjdk.java.net/pipermail/jdbc-spec-discuss/2013-February/000050.html >> ), >> Lance Andersen said "There is nothing in the SQL standard that >> would support the use of an '?' as anything but a parameter >> marker.". > "CREATE OPERATOR is a PostgreSQL extension. There are no > provisions for user-defined operators in the SQL standard." Exactly. The standard specifies the characters to use for the predicates that it defines, and provides no mechanism for adding additional predicates; but who in the world would want to exclude all extensions to the standard? > And by extension if indeed the standard does require the use of > "?" for parameters we are in violation there because the backend > protocol deals with $# placeholders and not "?" We're talking about a different specification that has question marks as parameter placeholders. That's in the Java Database Connector (JDBC) specification. (It is apparently also specified in other documents, although I'm not familiar enough with those to comment.) Note that it would create all sorts of pain if both the SQL statements and a connector issuing them used the same convention for substituting parameters; it is a *good* thing that plpgsql and SQL function definitions use a different convention than JDBC! The JDBC spec provides for escapes using curly braces (including product-specific escapes); it seems like a big mistake for us to have chosen a completely different mechanism for escaping the question mark character in a SQL statement. Perhaps the least painful path would be to add support for {?} as the escape for a question mark, and a connection option to supplement that with support for the legacy \? escape. I would bet a lot of money that even with an "if" test for that option, the curly brace escape would be faster than what's there now (when the option was not set). Some operators would look a little funny in Java string literals, but that's not so bad. -- Kevin Grittner EDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
