You can further control the generation of test data for individual columns by adjusting the Column fill parameters specified on the Detail tab of the column propery sheet.
The following column fill parameters are available:
- Null values - [Default: 0%] Specifies the percentage of values that can be left empty.
- Distinct values - [Default: 100%] Specifies the percentage of values that must be unique. This is a maximum value, and can change depending on the referential integrity parameters of primary key columns. Alternately, you can enter a specific value without a percentage sign, to indicate the exact number of column rows that should contain unique entries.
- Average Length - [read only] Used for estimating the size of the database (see Estimating Database Size). The value displayed is the maximum length for the data type defined for the column.
The following column properties also affect test data generation:
- Mandatory (M) - Specifies that the column must contain a value and sets Null value to 0%.
- Unique (U) - Specifies the column must contain a unique value and sets Null value to 0% and Distinct values to 100%.
- Foreign (F) - The column is a foreign key column and takes the value of the corresponding primary key column in the parent table.