Using the Nullable Columns Report

The Nullable Column report is helpful tool in identifying the nullable settings in effect for numeric and date columns in your Relativity catalog.

This is especially useful if you are creating writable tables as one of the requirements of a successful SQL UPDATE or INSERT operation is that columns not explicitly specified in the command must be nullable; see Nullable Columns Rule.

A nullable column is one that may be null. Null is not a value; it indicates the absence of a value. Since the rules of ODBC dictate that an error be returned if a numeric column contains non-numeric data, nullable settings can affect which columns can participate in an index, or as earlier mentioned, be a requirement of SQL UPDATE and INSERT operations.

There are a number of ways in which a column is marked as nullable:

In the Catalog tab of the Options pane, the Invalid Numerics Return NULL and Invalid Dates Return NULL options can be selected to set invalid numerics or dates to null.
If the column is derived from a data item that has a null value defined in the FD - see Defining Null Information.
Mark the column as Nullable in the Properties pane from the table definition - see Defining Insertable Tables.