All repository item properties are described in the XML repository definition with <property> tags. You can explicitly map an item property to a database column name through the column-names attribute; otherwise, the property name and database column name are assumed to be the same. For example, you can map the login property to the login_name property as follows:

<property name="login" column-names="login_name" data-types="string"/>

The column-names attribute of a property specifies the database column that stores the property. Each property must also define its data type with the data-types attribute. In the case of a multi-column id property, the data-types attribute is a comma-separated list of data types, where each entry corresponds to an entry in the column-names attribute. Each column can have a different data type. If no data type is specified, the string data type is used by default. The valid data type names and their Java and SQL representations are listed in the Data Type Mappings: Java and SQL section in the SQL Repository Reference chapter.