XML Database¶

Emakin uses an XML NoSQL database for storing large XML datasets. This is particularly suitable given Emakin's heavy reliance on XML data. Data is stored as a single large XML document with nested elements. Access is provided via server-side scripts using Xml.Load and $XmlRepository.Query methods, and on forms using the XML Database Query data source.

Emakin utilizes two types of XML databases: Domain and Process databases. The Process database is disabled by default and requires explicit administrator enablement.

Domain Database¶

The Domain database is shared across all processes within a domain. It's used for storing domain-wide data. All queries use XQuery. Emakin provides Save and Load functions for simpler operations. Save overwrites existing nodes; Load uses XQuery for retrieval.

Saving Data to the Domain Database¶

This example uses XmlNode.Save to store the Customer node under the Customer/<Id> path:

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$Xml.Save('Customer', 'Customer/' + $Xml.Evaluate('Id'));

Loading Data from the Domain Database¶

This example uses XmlNode.Load to retrieve the Customer node:

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$Xml.SelectSingle('Customer').Load('Customer[Id=1]');

More complex XQuery queries are also supported (see XQuery documentation). For example:

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$Xml.Load('for $c in /Customer ' +
        'where $c/Id=1 ' +
        'return ' +
        '  <Customer> ' +
        '    <Id>{ $c/Id }</Id> ' +
        '    <Name>{ $c/Name }</Name> ' +
        '  </Customer> ');

Process Database¶

The Process database is automatically created for each process and stores workflow data for reporting and statistics. This data mirrors the relational database but in a more compact XML format, facilitating report generation.

Instance Data¶

Instance metadata (within <Instance> tags) includes workflow details and a list of completed work items. A background job ("Instance Xml Database Replication") updates the database upon work item completion. Use the Background Jobs Manager to monitor this job.

Example Instance Data:

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<Instance>
    <Id>...</Id>
    <Number>...</Number>
    <State>...</State>
    <Start>...</Start>
    <End>...</End>
    <WorkItems>
        <WorkItem>
            <Id>...</Id>
            <Name>...</Name>
            <State>...</State>
            <Start>...</Start>
            <End>...</End>
            <CompletedBy>...</CompletedBy>
            <DataId>...</DataId>
            <DataRoot>...</DataRoot>
        </WorkItem>
        ...
    </WorkItems>
</Instance>

Form Data¶

Form data (within <form> tags) is similarly stored and updated upon work item completion. A background job ("Form Data Xml Database Replication") manages this update.

Example Form Data:

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<form Id="...">
    <MyRoot>
        <MyField>MyValue</MyField>
    </MyRoot>
</form>