Measure with Text Aggregator

Data cubes have multiple measures when different aggregations are required for a column.

Database Schema

The cube defined in this example is based on a single table that stores all the data. The table, named Fact, contains two columns: KEY and VALUE. The KEY column acts as a discriminator, while the VALUE column holds the measurements to be aggregated.

<roma:DatabaseSchema   id="_databaseSchema">
  <tables xsi:type="roma:PhysicalTable" id="_tab" name="Fact">
    <columns xsi:type="roma:PhysicalColumn" id="_col_key" name="KEY"/>
    <columns xsi:type="roma:PhysicalColumn" id="_col" name="VALUE" type="Integer"/>
    <columns xsi:type="roma:PhysicalColumn" id="_col_fact_country" name="COUNTRY"/>
    <columns xsi:type="roma:PhysicalColumn" id="_col_fact_cntinent" name="CONTINENT"/>
    <columns xsi:type="roma:PhysicalColumn" id="_col_fact_year" name="YEAR" type="Integer"/>
    <columns xsi:type="roma:PhysicalColumn" id="_col_fact_month" name="MONTH" type="Integer"/>
    <columns xsi:type="roma:PhysicalColumn" id="_col_fact_month_name" name="MONTH_NAME"/>
    <columns xsi:type="roma:PhysicalColumn" id="_col_fact_user" name="USER"/>
    <columns xsi:type="roma:PhysicalColumn" id="_col_fact_comment" name="COMMENT"/>
  </tables>
</roma:DatabaseSchema>

Note: This is only a symbolic example. For the exact definition, see the Definition section.

Query

This example uses a TableQuery, as it directly references the physical table Fact.

<roma:TableQuery  id="_query" table="_tab"/>

Note: This is only a symbolic example. For the exact definition, see the Definition section.

Cube, MeasureGroup and Measure with Text Aggregator

In this example, multiple measures are defined. All measures reference the VALUE column and use the following aggregation functions:

• SUM – Calculates the sum of the values.
• TextAgg – Text aggregation

<roma:PhysicalCube   id="_cube" name="MeasuresTextAggregatorsCube" query="_query">
  <dimensionConnectors foreignKey="roma:PhysicalColumn _col_fact_country" dimension="roma:StandardDimension _dim_town"/>
  <dimensionConnectors foreignKey="roma:PhysicalColumn _col_fact_year" dimension="roma:TimeDimension _dim_time"/>
  <measureGroups>
    <measures xsi:type="roma:SumMeasure" id="_measure1" name="Sum of Value" column="_col"/>
    <measures xsi:type="roma:TextAggMeasure" id="_measure6" name="Comment" column="roma:SQLExpressionColumn _sql_expression" orderByColumns="orderedColumn" separator=", "/>
  </measureGroups>
</roma:PhysicalCube>

Note: This is only a symbolic example. For the exact definition, see the Definition section.

Definition

This files represent the complete definition of the catalog.

<?xml version="1.0" encoding="UTF-8"?>
<xmi:XMI xmi:version="2.0" xmlns:xmi="http://www.omg.org/XMI" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:roma="https://www.daanse.org/spec/org.eclipse.daanse.rolap.mapping">
  <roma:OrderedColumn id="orderedColumn" column="_col_fact_comment"/>
  <roma:Catalog name="Measure - Text Aggregator" cubes="_cube" dbschemas="_databaseSchema"/>
  <roma:DatabaseSchema id="_databaseSchema">
    <tables xsi:type="roma:PhysicalTable" id="_tab" name="Fact">
      <columns xsi:type="roma:PhysicalColumn" id="_col_key" name="KEY"/>
      <columns xsi:type="roma:PhysicalColumn" id="_col" name="VALUE" type="Integer"/>
      <columns xsi:type="roma:PhysicalColumn" id="_col_fact_country" name="COUNTRY"/>
      <columns xsi:type="roma:PhysicalColumn" id="_col_fact_cntinent" name="CONTINENT"/>
      <columns xsi:type="roma:PhysicalColumn" id="_col_fact_year" name="YEAR" type="Integer"/>
      <columns xsi:type="roma:PhysicalColumn" id="_col_fact_month" name="MONTH" type="Integer"/>
      <columns xsi:type="roma:PhysicalColumn" id="_col_fact_month_name" name="MONTH_NAME"/>
      <columns xsi:type="roma:PhysicalColumn" id="_col_fact_user" name="USER"/>
      <columns xsi:type="roma:PhysicalColumn" id="_col_fact_comment" name="COMMENT"/>
    </tables>
  </roma:DatabaseSchema>
  <roma:SQLExpressionColumn id="_sql_expression" name="sql_expression">
    <sqls sql="CONCAT(&quot;Fact&quot;.&quot;USER&quot;, ' : ',  &quot;Fact&quot;.&quot;COMMENT&quot;)">
      <dialects>generic</dialects>
      <dialects>h2</dialects>
    </sqls>
  </roma:SQLExpressionColumn>
  <roma:TableQuery id="_query" table="_tab"/>
  <roma:Level id="_level_town" name="Town" column="_col_key"/>
  <roma:Level id="_level_month" name="Month" column="_col_fact_month" type="TimeMonths" nameColumn="_col_fact_month_name"/>
  <roma:Level id="_level_country" name="Country" column="_col_fact_country"/>
  <roma:Level id="_level_continent" name="Continent" column="_col_fact_cntinent"/>
  <roma:Level id="_level_year" name="Year" column="_col_fact_year" type="TimeYears"/>
  <roma:Hierarchy id="_hierarchy_town" name="TownHierarchy" levels="_level_continent _level_country _level_town" primaryKey="_col_key" query="_query"/>
  <roma:Hierarchy id="_hierarchy_time" name="TimeHierarchy" levels="_level_year _level_month" primaryKey="_col_key" query="_query"/>
  <roma:StandardDimension id="_dim_town" name="Town" hierarchies="_hierarchy_town"/>
  <roma:TimeDimension id="_dim_time" name="Time" hierarchies="_hierarchy_time"/>
  <roma:PhysicalCube id="_cube" name="MeasuresTextAggregatorsCube" query="_query">
    <dimensionConnectors foreignKey="_col_fact_country" dimension="_dim_town"/>
    <dimensionConnectors foreignKey="_col_fact_year" dimension="_dim_time"/>
    <measureGroups>
      <measures xsi:type="roma:SumMeasure" id="_measure1" name="Sum of Value" column="_col"/>
      <measures xsi:type="roma:TextAggMeasure" id="_measure6" name="Comment" column="_sql_expression" orderByColumns="orderedColumn" separator=", "/>
    </measureGroups>
  </roma:PhysicalCube>
</xmi:XMI>

Turorial Zip

This files contaisn the data-tables as csv and the mapping as xmi file.

Download Zip File