Allow NULLs

The allow NULLs option is only available for the details stereotyped attribute on an entity class.

The allow NULLs option determines whether NULL values are permitted on the corresponding database field. Setting this option to no means a Not Null qualifier is included with this field in the generated DDL script.

The default value for this option is dependent on the underlying data type of the field. The default value of this option for the attributes for fields of type SVR_BOOLEAN, SVR_CHAR, SVR_FLOAT, SVR_DOUBLE, SVR_MONEY, SVR_INT8, SVR_INT16, SVR_INT32 is no.

The default value of this option for the attributes of type SVR_BLOB, SVR_DATE, SVR_DATETIME, SVR_STRING, SVR_INT64 is yes.

For more information, see Null considerations.