image/svg+xml TABLE_NAME Column_Name Column_Name* * An asterisk following a column name indicates the column has a controlled vocabulary, a vocabulary defined by the the keys of a support table. TABLE NAME Column Names Relationship Key Visual Key Relationship betweencolumns of two tables ∅ A ∅ symbol following a column name indicates the column is allowed to be NULL. One-to-one One-to-many One-to-zero-or-one One-to-zero-or-more