mirror of
https://github.com/postgres/postgres.git
synced 2025-06-03 00:02:26 -04:00
9fe6319dcc
If an ORDER BY item in SELECT is a bare identifier, the parser first seeks it as an output column name of the SELECT (for SQL92 compatibility). However, ruleutils.c is expecting the SQL99 interpretation where such a name is an input column name. So it's possible to produce an incorrect display of a view in the (admittedly pretty ill-advised) case where some other column is renamed in the SELECT output list to match an ORDER BY column. This can be fixed by table-qualifying such names in the dumped view text. To avoid cluttering less-ill-advised queries, we'd like to do so only when there's an actual name conflict. That requires passing the current get_query_def call's resultDesc parameter down to get_variable, so that it can determine what the output column names are. In hopes of reducing rather than increasing notational clutter in ruleutils.c, I moved that value into the deparse_context struct and removed it from the parameter lists of get_query_def's other subroutines. I made a few other cosmetic changes while at it: * Likewise move the colNamesVisible parameter into deparse_context. * Rename deparse_context's windowTList field to targetList, since it's no longer used only in connection with WINDOW clauses. * Replace the special_exprkind field with a bool inGroupBy, since that was all it was being used for, and the apparent flexibility of storing a ParseExprKind proved to be illusory. (We need a separate varInOrderBy field to make this patch work.) * Remove useless save/restore logic in get_select_query_def. In principle, this bug is quite old. However, it seems unreachable before 1b4d280ea, because before that the presence of "new" and "old" entries in a view's rangetable caused us to always table-qualify every Var reference in dumped views. Hence, back-patch to v16 where that came in. Per bug #18589 from Quynh Tran. Discussion: https://postgr.es/m/18589-70091cb81db1a3f1@postgresql.org
PostgreSQL Database Management System ===================================== This directory contains the source code distribution of the PostgreSQL database management system. PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. This distribution also contains C language bindings. PostgreSQL has many language interfaces, many of which are listed here: https://www.postgresql.org/download/ See the file INSTALL for instructions on how to build and install PostgreSQL. That file also lists supported operating systems and hardware platforms and contains information regarding any other software packages that are required to build or run the PostgreSQL system. Copyright and license information can be found in the file COPYRIGHT. A comprehensive documentation set is included in this distribution; it can be read as described in the installation instructions. The latest version of this software may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.