On Tue, 12 Feb 2019, Laurenz Albe wrote:
If you insert a string into a "date" column, PostgreSQL will try to convert the string to a date with the type input function. The type input function fails on an empty string, since it cannot parse it into a valid "date" value. This also applies to the empty string.
Laurenz, All my previous databases with date columns were required to have an entry because each row contatined spatio-temporal sampling data. The table in this business-oriented application is not required to have a next_contact date and (the crucial point) is that I conflated date values with string values. As you wrote, a date column is converted from the entered string to a non-string date type and requires an explicit null when there is no value to be stored for that column. Thanks very much, Rich
