Hi. I recently ran a query that generate the same error as this: SELECT * FROM generate_series(1,10) ORDER BY 'foo'; ERROR: non-integer constant in ORDER BY LINE 1: SELECT * FROM generate_series(1,10) ORDER BY 'foo';
The query was generated by an app (and the result somewhat inadvertent), so it was easy enough to change and I'm not asking here about a practical problem. I am curious though about why this "limitation" exists. I get that integer constants are reserved for sorting by column numbers. But if Postgres already knows that it's a non-integer constant, why not let it go through with the (admittedly pointless) ordering? Also, I couldn't see that this was explictly mentioned in the documentation. The relevant pieces seemed to be: *Each expression can be the name or ordinal number of an output column ( SELECT list item), or it can be an arbitrary expression formed from input-column values.* followed closely by: *It is also possible to use arbitrary expressions in the ORDER BY clause, including columns that do not appear in the SELECT output list. (http://www.postgresql.org/docs/9.1/static/sql-select.html#SQL-ORDERBY) * And looking at the expressions page ( http://www.postgresql.org/docs/8.4/static/sql-expressions.html), the first type of value expression is a "constant or literal expression." So nothing seems to explicitly rule out a literal ORDER BY. I'm not sure if it would do violence to something I'm missing, but would the following combined statement work for the documentation? *"Each expression can be the name or ordinal number of an output column ( SELECT list item), or it can be an arbitrary expression. The expression can include column values--whether they appear in the SELECT output list or not. An expression may not, however, consist solely of a non-integer constant. And an integer constant will be interpreted as the ordinal number of an output column** " * Thanks in advance. Ken -- AGENCY Software A data system that puts you in control *http://agency-software.org/* ken.tan...@agency-software.org (253) 245-3801
