A filter assigns a SQL expression to a table column. ### Export filter An export filter is evaluated during the export phase. The column values will be replaced by the result of the expression when the export file is written. ${old-value} is a synonym for the filtered column. With the filter EMPLOYEE.NAME := lower(${old-value}) The employee names will be exported with all letters lowercase: ### Literal filter A literal filter is also evaluated during the export phase. The result will be written literally into the export file. During the import phase, it will be evaluated as a SQL expression. To define a literal filter, add the prefix "literal:" to the filter expression. The filter: replaces employee names with numbers from a sequence in the target database. ### Import filter An import filter is evaluated during the import phase. Import filters are especially useful for filtering primary key columns. Filters on primary key columns are automatically applied to the corresponding foreign key columns. With an import filter, it’s guaranteed that a “null”-value remains null and that a foreign key value is mapped to the same value as the primary key even if the filter expression is not a deterministic function. This filter uses a sequence to generate new EMPNOs during the import phase: ### Filter templates Templates allow defining filters based on a condition on a column.