21.3 Creating XML Data Models

Oracle Reports Services introduces a greater level of sophistication in the types of data models you can create using Oracle Reports XML tags. Use XML for:

Creating Multiple Data Sources
Linking Between Data Sources
Creating Group Hierarchies Within Each Data Source
Creating Cross-Product (Matrix) Groups
Creating Formulas, Summaries, and Placeholders at Any Level
Creating Parameters

This section provides examples of these uses of XML.

In addition to these data model types, Oracle Reports Services provides support for using PL/SQL in your XML. This includes support for local program units, report-level triggers, and attached PL/SQL libraries.

21.3.1 Creating Multiple Data Sources

The <data> tag now supports the creation of multiple data sources as well as the new pluggable data sources. Each data source is enclosed within its own <dataSource> tag. The data type definition for the dataSource element is:

<!ELEMENT dataSource
  ((select|plugin|plsql),
  comment?,
  displayInfo?,
  formula*,
  group*)>
<!ATTLIST dataSource
  name CDATA #IMPLIED
  defaultGroupName CDATA #IMPLIED
  maximumRowsToFetch CDATA #IMPLIED>

The following example creates two SQL data sources and names them Q_1 and Q_2. It also creates all the necessary columns for the data sources and the default group—giving the group the specified defaultGroupName or defaulting its own name if defaultGroupName is not specified.

<report name="anyname" DTDVersion="9.0.2.0.0">
  <data>
    <dataSource name="Q_1" defaultGroupName="G_DEPARTMENTS">
      <select>
      select * from departments
      </select>
    </dataSource>
    <dataSource name="Q_2" defaultGroupName="G_EMPLOYEES">
      <select>
      select * from employees
    </select>
    </dataSource>
  </data>
</report>

21.3.2 Linking Between Data Sources

In the presence of multiple data sources, it may be desirable to link the data sources together to create the appropriate data model. Oracle Reports data model link objects have also been exposed through Oracle Reports XML. They support both group- and column-level links. You can specify any number of links to create the required data model.

The data type definition for the link element is:

<!ELEMENT link EMPTY>
<!ATTLIST link
  name CDATA #IMPLIED
  parentGroup CDATA #IMPLIED
  parentColumn CDATA #IMPLIED
  childQuery CDATA #IMPLIED
  childColumn CDATA #IMPLIED
  condition (eq|lt|neq|gt|gteq|like|notLike) "eq"
  sqlClause (startWith|having|where) "where">

The link element is placed within a data element and can link any two dataSource objects defined within the data element. For example:

<report name="anyname" DTDVersion="9.0.2.0.0">
  <data>
    <dataSource name="Q_1" defaultGroupName="G_DEPARTMENTS">
      <select>
        select * from departments
      </select>
    </dataSource>
    <dataSource name="Q_2" defaultGroupName="G_EMPLOYEES">
      <select>
        select * from employees
      </select>
    </dataSource>
    <link name="L_1" parentGroup="G_DEPARTMENTS"
          parentColumn="DEPARTMENT_ID" childQuery="Q_2" 
          childColumn="DEPARTMENT_ID1" condition="eq" sqlClause="where"/>
  </data>
</report>

Within the link element, Oracle Reports defaulting mechanism recognizes DEPARTMENT_ID1 as an alias to the DEPARTMENT_ID column in the EMPLOYEES table without your having to explicitly create such an alias.

21.3.3 Creating Group Hierarchies Within Each Data Source

With Oracle Reports Services, the complete group hierarchy is available to you. You can specify all the columns within each group and break the order of those columns. You can use formulas, summaries, and placeholders to further customize the objects within groups.

The data type definition for the group element is:

<!ELEMENT group
  (field|exception|rowDelimiter|xmlSettings|displayInfo|dataItem|formula|
  summary|placeholder|filter|comment)*>
<!ATTLIST group
  name CDATA #IMPLIED
  fillColor CDATA #IMPLIED
  lineColor CDATA #IMPLIED
  formatTrigger CDATA #IMPLIED>

The following example demonstrates the use of a group element to create a break group under a data source.

<report name="anyname" DTDVersion="9.0.2.0.0">
  <data>
    <dataSource name="Q_1">
      <select>
        select * from employees
      </select>
      <group name="G_DEPARTMENTS">
        <dataItem name="DEPARTMENT_ID"/>
      </group>
      <group name="G_EMPLOYEES">
        <dataItem="EMPLOYEE_ID"/>
        <dataItem="FIRST_NAME"/>
        <dataItem="LAST_NAME"/>
        <dataItem="JOB_ID"/>
        <dataItem="MANAGER_ID"/>
        <dataItem="HIRE_DATE"/>
        <dataItem="SALARY"/>
        <dataItem="COMMISSION_PCT"/>
      </group>
    </dataSource>
  </data>
</report>

21.3.4 Creating Cross-Product (Matrix) Groups

Cross-product groups allow you to define a matrix of any number of groups in the data model. The dimension groups in a cross product may exist in the same data source or may be combined from different data sources to create a matrix. In support of this flexibility, the <crossProduct> tag is placed within the <data> tag after all the data sources and groups have been created.

The data type definition for the crossProduct element is:

<!ELEMENT crossProduct
  (xmlSettings|displayInfo|dimension|(formula|summary|placeholder)*|comment)*>
<ATTLIST crossProduct
  name CDDATA #IMPLIED
  mailText CDDATA #IMPLIED>

The following example demonstrates the creation of a single-query matrix.

<report name="anyname" DTDVersion="9.0.2.0.0">
  <data>
    <dataSource name="Q_1">
      <select>
        select * from employees
      </select>
      <group name="G_DEPARTMENTS">
        <dataItem name="DEPARTMENT_ID"/>
      </group>
      <group name="G_JOB_ID>
        <dataItem name="JOB_ID"/>
      </group>
      <group name="G_MANAGER_ID">
        <dataItem name="MANAGER_ID"
      </group>
      <group name="G_EMPLOYEE_ID">
        <dataItem name="EMPLOYEE_ID"/>
      <dataItem name="FIRST_NAME"/>
        <dataItem name="LAST_NAME"/>
        <dataItem name="HIRE_DATE"/>
        <dataItem name="SALARY"/>
        <dataItem name="COMMISSION_PCT"/>
      </group>
    </dataSource>
    <crossProduct name="G_Matrix">
      <dimension>
        <group name="G_DEPARTMENTS">
      </dimension>
      <dimension>
      <group name="G_JOB_ID">
      </dimension>
      <dimension>
      <group name="G_MANAGER_ID">
      </dimension>
    </crossProduct>
  </data>
</report>

21.3.5 Creating Formulas, Summaries, and Placeholders at Any Level

You can place formulas, summaries, and placeholders at any level within the data model. Additionally, you have complete control over all the attributes for each of these objects.

The following example demonstrates the creation of a report-level summary whose source is based on a group-level formula column.

<report name="anyname" DTDVersion="9.0.2.0.0">
  <data>
    <dataSource name="Q_1">
      <select>
        select * from employees
      </select>
      <group name="G_EMPLOYEES">
        <dataItem="EMPLOYEE_ID"/>
        <dataItem name="EMPLOYEE_ID"/>
        <dataItem name="FIRST_NAME"/>
        <dataItem name="LAST_NAME"/>
        <dataItem name="HIRE_DATE"/>
        <dataItem name="SALARY"/>
        <dataItem name="COMMISSION_PCT"/>
        <dataItem name="DEPARTMENT_ID"/>
        <formula name="CF_REMUNERATION" source="cf_1formula"
          datatype="number" width="20" precision="10"/>
      </group>
    </dataSource>
    <summary name="CS_REPORT_LEVEL_SUMMARY" function="sum" width="20"
      precision="10" reset="report" compute="report"/>
  </data>
  <programUnits>
    <function name="cf_1formula" returnType="number">
      <textSource>
        <![CDATA[
          function CF_1Formula return Number is
          begin
          return (:salary + nvl(:commission_pct,0));
          end;
        ]]>
      </textSource>
    </function>
  </programUnits>
</report>

21.3.6 Creating Parameters

In Oracle Reports XML, the parameter element is placed between open and close data tags. The data type definition for the parameter element is:

<!ELEMENT parameter (comment?|listOfValues?)>
<!ATTLIST parameter
  name CDATA #REQUIRED
  datatype (number|character|date) "number"
  width CDATA "20"
  scale CDATA "0"
  precision CDATA "0"
  initialValue CDATA #IMPLIED
  inputMask CDATA #IMPLIED
  validationTrigger CDATA #IMPLIED
  label CDATA #IMPLIED
  defaultWidth CDATA #IMPLIED
  defaultHeight CDATA #IMPLIED>

The following example demonstrates a dynamic list of values (LOV), an initial value, and a validation trigger.

<report name="anyname" DTDVersion="9.0.2.0.0">
  <data>
    <dataSource name="Q_1" defaultGroupName="G_DEPARTMENTS">
      <select>
        select * from departments
      </select>
      </dataSource>
        <parameter name="P_LAST_NAME" datatype="character" precision="10"
          initialValue="SMITH" validationTrigger="p_last_namevalidtrigger"
          defaultWidth="0" defaultHeight="0">
          <listOfValues restrictToList="yes">
            <selectStatement hideFirstColumn="yes">
              <![CDATA[select last_name, 'last_name||'-'||employee_id'
                from employees]]>
            </selectStatement>
          </listOfValues>
        </parameter>
  </data>
  <programUnits>
    <function name="p_last_namevalidtrigger" returnType="character">
      <textSource>
        <![CDATA[function P_LAST_NAMEValidTrigger return boolean is 
          last_name char(20);
          begin
            select count(*) into last_name from employees
              where upper(last_name)=upper(:p_last_name);
            exception when OTHERS then return(FALSE);
            end;
            return(TRUE);
          end;
        ]]>
      </textSource>
    </function>
  </programUnits>
</report>