On Wed, Mar 26, 2014 at 7:12 PM, RSmith <rsm...@rsweb.co.za> wrote: > > Double quotes are not part of the standard, just allowed by most systems > in lieu of single quotes, but you are correct about back-quotes not being > part of the standard either, but they will be understood by most SQL > engines to mean `NOT a string`. (Which is why it is easier to use them in > stead of double quotes around things that are explicitely not strings, like > identifiers). What is in the standard seems to not always be adhered to and > different in every Engine, but my advice was more towards making life > easier on the programmer with respect to the SQL, not prescribing standard > adherence at all - though I would strongly advise avid use of legibility > punctuation and format as they are great tools for being able to comprehend > your own SQL 6-months down the line. > > I'm somewhat a fan of MSSQL's brackets for the above reason - looking at a > complex bit of SQL in MSSQL guise might look cumbersome with those very > bold word-boundaries, but you cannot ever claim that it isn't vividly clear > in one glance which bits are identifiers and which not, though it's hard to > make a real case for it.
You may be right. I do have have the text of the actual standard in front of me. My reference for double quote being part of the standard is: http://savage.net.au/SQL/sql-92.bnf which states its source: Using Appendix G of "Understanding the New SQL: A Complete Guide" by J Melton and A R Simon (Morgan Kaufmann, 1993, ISBN 0-55860-245-3) as the source of the syntax, here is (most of) the BNF syntax for SQL-92. The missing parts are the Cobol, Fortran, MUMPS, Pascal and PL/I variable definition rules. And goes on to show the following snippets: <double quote> ::= " <delimited identifier> ::= <double quote> <delimited identifier body> <double quote> Since it is not the standard, it could be wrong, but my experience indicates that double quotes are never "officially" a string delimiter, only an identifier delimiter. Implementations vary, of course. In any case, I agree with you about the MSSQL use of brackets. They stand out and are unambiguously not a string! -- Scott Robison _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
