The Mertech Flex2SQL GUI migration tool and Mertech drivers are being modified to use 00-00-0000 as the default NULL value for DataFlex DF_DATE and DF_DATETIME fields.
The default NULL date value was previously set to 0001-01-01 to be consistent with the DataFlex dummy zero date setting.
Note: This value is internally assigned to the DF_LOW constant.
Records are added to the database through the Flex2SQL GUI migration tool or through a DataFlex application. NULL dates are set to DF_LOW.
Additional records are added to the database, possibly outside of DataFlex, that have their NULL dates set to 0000-00-00.
When an application performs a LT or LE FIND on the database using an index with a date column segment and does not assign a minimum date value to the search field, the Mertech drivers automatically fill in the field with the DF_LOW value.
If DF_LOW is set to 0001-01-01, records with a date value of 00-00-0000 will not be found.