I want to combine columns in two tables and use the exported resulting table for statistical analyses. The SQL script is: INSERT INTO waterchem (site, sampdate, param, quant, ceneq1, low, high, stream, basin) SELECT c.site, c.sampdate, c.param, c.quant, c.ceneq1, c.low, c.high, s.stream, s.basin FROM chemistry as c, sites as s WHERE c.site == s.siteid; The problem is that both c.site and s.siteid are of type VARCHAR(16) and postgres tells me, ERROR: operator does not exist: character varying == character varying and provides the hint to add explicit type casts. Since the string length of site/siteid varies I don't see how to cast both to a working type. Please suggest how I can populate this table while avoiding the operator error. Rich -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general