Douglas Little wrote: > I need to evaluate an expression that I have stored in a table, and not sure how to force evaluation > of a column value. [...] > The pass/fail query looks something like this > > Update testscore > Set metricstatus = case when table_a.col_a = table_b.col_b then 'PASS' else 'FAIL' end > .. > Where testrunid=x > > I want to replace the table_a.col_a = table_b.col_b with the expression stored in the test table and > evaluate. > > I'm thinking - it's dynamic sql, so I need to build the statement and then evaluate using a function. > > Anybody have any comments? I would consider composing the statement in the application code: SELECT the expression you need, compose the statement, send it to the database. If you need to do it on the database side, PL/pgSQL is your friend. Since PostgreSQL 9.0 you can also use PL/pgSQL in the DO SQL statement without having to define a function, but that will probably not help if you need a return value. Yours, Laurenz Albe -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
