The Tamino forms handler allows database queries to be automatically constructed using the values in multiple fields of an HTML form.

The commands used for building and sending a query to Tamino are very similar to those required for creating an XML document.

To compose a query and send it to Tamino, encode the following into the HTML form:

• The name of the database and collection to be queried;

• The fact that you want to compose a query (rather than create an XML document);

• The query itself.

The following example illustrates the principle:

Performing a Query

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Specifying the Database, Collection and Doctype

This is the same as for creating an XML document, as described above.

Composing a Query

To indicate that you want to use the HTML form to compose a query, use the following code in the HTML form:

<input type=hidden name="_HTMLreq" value="_XQL">

Specifying the Query's Nodes and Filters

A query consists of node selectors and filters. A node selector specifies the family of elements to be retrieved. A filter specifies a required subset of the elements (i.e. the part of a query that is enclosed in square brackets "[" and "]").

The node selector is specified in an HTML input statement with the following syntax:

<input type=hidden name="XQLNode" value="NodeAddress">

where NodeAddress is an XPath expression that identifies the location of the element within the document.

The filter is specified in another HTML input statement for a field that is visible in the browser.

Example

<input type=hidden name="XQLNode" value="patient">
<input type="text" size="30" name="name/surname~">

This generates a query of the form

/patient[name/surname~="ValueOfInputEntry"]

where ValueOfInputEntry stands for the value that you type in to the input field in the browser.