Database Interface Concepts

Database Interface Concepts (DBI’s) define statements and rules for moving data between Fox and Oracle.

CONCEPTS

• Allows SQL, DML and PL/SQL statements to be specified
• DBI’s are always defined in the same place, so are easy to find and maintain
• It is good practice to use one DBI for each table subject area. I.E. All statements relating to table EMP in an EMP DBI. For statements that join tables, think about which table drives the resultant cardinality and use DBI accordingly
• EMP join DEPT – use EMP DBI
• EMP join DEPT GROUP BY dept.id – use DEPT DBI
• The tags that are used are <fm:db-interface-list> and <fm:db-interface> and can be found under the <fm:action-list> and above <fm:presentation> at module level.

EXAMPLES

Two very simple DBI’s:

<fm:db-interface-list>
  <fm:db-interface name="dbint-emp">
    <fm:query name="qry-emp">
      <fm:select>
SELECT *
FROM   scott.emp
      </fm:select>
    </fm:query>
  </fm:db-interface>
  <fm:db-interface name="dbint-dept">
    <fm:query name="qry-dept">
      <fm:select>
SELECT *
FROM   scott.dept
      </fm:select>
    </fm:query>
    </fm:db-interface>
</fm:db-interface-list>