https://community.appian.com/discussions/f/integrations/5696/team-i-have-a-database-view-already-created-i-am-now-trying-to-creaTeam, I have a database view already created. I am now trying to create a data type &amp; data store in appian designer so that i can query the database using a!queryentity(). But it doesn&#39;t allow me stating that a_id is missing as it is the primary key.en-USTelligent Community 12https://community.appian.com/thread/21662?ContentTypeID=1Thu, 20 Aug 2015 21:47:26 GMTd3a83456-d57b-489c-a84c-4e8267bb592a:4a58b32f-ca4b-4ec6-84c9-f198611c621asenthilarThis is what we do to overcome this issue:<br />1) Add rownum as a column in the view (eg CREATE VIEW &lt;viewname&gt; AS SELECT rownum ROW_ID, &lt;other required columns&gt;...)<br />2) In XSD, use @Table annotation to point to this View and designate the ROW_ID column with @Id annotation<div style="clear:both;"></div>https://community.appian.com/thread/21653?ContentTypeID=1Thu, 20 Aug 2015 18:44:57 GMTd3a83456-d57b-489c-a84c-4e8267bb592a:424261ab-23fa-4bfa-9129-196d439ace7eJacob Cohen - Project Leader - Macedon TechnologiesHere&#39;s a link to some documentation on creating your XSD:<br /><a href="https://forum.appian.com/suite/help/7.10/Custom_Data_Types_from_XSD.html#-matching-a-cdt-to-an-existing-table-schema">forum.appian.com/.../Custom_Data_Types_from_XSD.html</a><br />Check out the &quot;&lt;xsd:element name=&quot;id&quot; type=&quot;xsd:int&quot;&gt;&quot; tag for an example of a primary key definition.<div style="clear:both;"></div>https://community.appian.com/thread/21652?ContentTypeID=1Thu, 20 Aug 2015 18:43:40 GMTd3a83456-d57b-489c-a84c-4e8267bb592a:a9bad98a-f48d-4191-9be2-6a6d7845a27csikhivahans@manikandang You need to do two things here:<br />1. Provide the name of the database view to the 'name' attribute of @Table annotation.<br />2. Provide the name of the column (which ever you feel is sufficient to uniquely identify a record) in your view to the 'name' attribute of the @Column annotation and designate this element with @Id annotation. <br /><br />Also please remember that there may not be a need to drop the view (Assuming that a working View is in place) because if the XSD doesn't map to the database entity it means that there is a problem with XSD, and we should try rectifying the problem in same.<br /><br />Here's an example of how you may do it:<br /><br /><xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:tns="test.com" targetNamespace="test.com"><br /> <xsd:complexType name="nameOfCdt"><br /> <xsd:annotation><br /> <xsd:appinfo source="appian.jpa"><br /> @Table(name="nameOfDatabaseView")<br /> </xsd:appinfo><br /> </xsd:annotation><br /> <xsd:sequence><br /> <xsd:element name="nameOfUniqueIdColumnInCdt" type="xsd:int"><br /> <xsd:annotation><br /> <xsd:appinfo source="appian.jpa">@Id @Column(name="nameOfUniqueIdColumnInDatabaseView")</xsd:appinfo><br /> </xsd:annotation><br /> </xsd:element><br />\ t<--\tOther columns goes here\t--><br /> </xsd:sequence><br /> </xsd:complexType><br /></xsd:schema><br /><br />And if you didn't make a search prior to posting, I would like to suggest to do so, as I remember there are some posts which resembles your query.<div style="clear:both;"></div>https://community.appian.com/thread/21647?ContentTypeID=1Thu, 20 Aug 2015 17:34:25 GMTd3a83456-d57b-489c-a84c-4e8267bb592a:d5b96d82-56ef-4098-b8e0-907f16c4fff0neelimajDefine a primary key to the cdt xsd file using @id to define primary key.. If you do not define any primary key.. Appian automatically creates a primary key with name a_id.. Remove the previous table and publish the xsd again with primary key defined..<div style="clear:both;"></div>