Database Services

Description

Database services allow to create pvmanager services based on database queries. Each service represents a database and each method represents a query. The query results are automatically mapped to VTable, based on the metadata coming from the database driver.

XML syntax

Here is an example of an XML file describing a jdbc service:

<?xml version="1.0" encoding="UTF-8"?>
<jdbcService ver="1" name="jdbcSample" description="A test service">
    <jdbcUrl>jdbc:mysql://localhost/test?user=username&amp;password=mypwd</jdbcUrl>
    <methods>
        <method name="query" description="A test query">
            <query>SELECT * FROM Data</query>
            <result name="result" description="The query result"/>
        </method>
        <method name="insert" description="A test insert query">
            <query>INSERT INTO `test`.`Data` (`Name`, `Index`, `Value`) VALUES (?, ?, ?)</query>
            <argument name="name" description="The name" type="VString"/>
            <argument name="index" description="The index" type="VNumber"/>
            <argument name="value" description="The value" type="VNumber"/>
        </method>
    </methods>
</jdbcService>

Each service method correspon to one command, with specific mappings. A service is a collection of different mehods.

Syntax	Description
`jdbcService`	Version is required to be "1". Name and description of the service are required
`jdbcUrl`	Database url for the JDBC driver. The correct driver must have been initialized. The syntax is driver dependent. Consult JDBC documentation.
`methods`	List of methods must be provided
`method`	Each method must have a name and a description
`query`	The query passed to the database driver. It can contain parameters marked as '?'. Parameters are distinguished by position.
`argument`	Arguments are optional, but they must match the number of '?' specified in the query. Each argument must have a name, a description and a type. Supported type include: VString, VNumber.
`result`	Result must include a name and a description. If the result is present, the query is executed expecting a result, and the result is mapped to a VTable.