There is no requirement to have both the tags for the same representation. Instead of writing the way you have written above following is the way to write it.
<property column="LOGIN_NAME" generated="insert" lazy="false" name="loginName" not-null="true" type="java.lang.String" unique="true" sql-type="VARCHAR(128)" length="128">
</property>
The column tag is part of the property tag itself. You only need to define it once. Its not required to add same properties again and again.