Hi, I am trying to map a composite key from a different CDT to another one

RE: Hi, I am trying to map a composite key from a different CDT to another one

Peter Lewis — Fri, 08 May 2020 13:44:54 GMT

You can import it, but you can't actually use it. If you do this, you will see a message that says: "Data types without primary keys, or with more than one primary key, prevent data stores from publishing. In order to publish a data store that contains this data type, you must modify the data type so that it has only one primary key, then publish the data store. Otherwise, the data store will be saved as a draft."

The CDT it self will be created but when you attempt to publish the data store it will fail. This means you can't read or write to the database, so the CDT itself becomes essentially useless. Composite keys are not supported in Appian when reading / writing to a database.

RE: Hi, I am trying to map a composite key from a different CDT to another one

AK47 — Fri, 08 May 2020 01:44:03 GMT

when creating CDT (Data Type), choose "create from database table or view". If your database has the composite primary key, CDT also has it.

RE: Hi,
I am trying to map a composite key from a different CDT to another one

ChristineLHutchison — Tue, 22 Mar 2016 18:21:25 GMT

You need to map the @ID to a real column in the table or view and it can only map to one column. If your table does not have a unique column, one idea is to create a view that has a viewID column. That column can be a concat of the two columns with a separator in between (as 111 is not the same as 1_11 or 11_1). Then use this column as the @ID.

RE: Hi,
I am trying to map a composite key from a different CDT to another one

PhilB — Tue, 22 Mar 2016 17:03:48 GMT

I'll say it again - you can't map a subCDT as an ID as you are doing in that XSD.

RE: Hi,
I am trying to map a composite key from a different CDT to another one

aswinb608 — Tue, 22 Mar 2016 17:01:02 GMT

Hi,
I have several variants of this subCDT inside the main cdt based on the type....attached is a generalized version of the CDT....based on the column "type" inside "default1" cdt i have different types of environments called uat, prod, commercial, test etc which are of type "default1"....which is the subCDT....I had early attached @Id at the beginning before the @Column....seeing above from sonalk's code the only change I see is attaching @Id after @Column....but I still get that same error i mentioned above...attaching the xsd...

default1.xsd

RE: Hi,
I am trying to map a composite key from a different CDT to another one

PhilB — Tue, 22 Mar 2016 14:29:15 GMT

@aswinb608 You can't map a composite key in the way you are attempting to. I believe the @Id annotation can only be used with a single column of, for example, string or integer.

You could select one of the composite keys and map that as an @Id, but you could see odd behaviour, such as only getting a single row when that key is actually repeated several times. This can actually work, provided any query against that table always uses that key.

Your other alternatives (as mentioned above) are to have a view created that provides a unique identifier, or to use the query database smart service.

RE: Hi,
I am trying to map a composite key from a different CDT to another one

sonalk — Tue, 22 Mar 2016 04:06:56 GMT

Hi Ashwin,
With reference to the XSD code provided by you, try with the code mentioned below :
<xsd:element name="subCDT" nillable="true" type="tns:subCDTType">
<xsd:annotation>
<xsd:appinfo source="appian.jpa">@Column(name="foriegn_composite_key_to_sub", columnDefinition="NUMBER(10,0)") @Id </xsd:appinfo>
</xsd:annotation>
</xsd:element>

RE: Hi,
I am trying to map a composite key from a different CDT to another one

aswinb608 — Mon, 21 Mar 2016 22:04:55 GMT

Hi Philb,

Please apologize me if I understood this wrong from Appian forum as mentioned in the link:forum.appian.com/.../Database_Schema_Best_Practices.html

It asks me to denote that key with @Id which I did but seems like what I understood was wrong. Can you please explain the location where I need to put @Id in because I am not following the vague explanation on forum which doesn't have any examples.

RE: Hi,
I am trying to map a composite key from a different CDT to another one

PhilB — Mon, 21 Mar 2016 21:12:26 GMT

@jacobc Good point, I forgot about the Query Database Smart Service :)

@aswinb608 You can't represent a composite key as you've done there. The error message is telling you that you can't use the @Id annotation in that fashion.

RE: Hi,
I am trying to map a composite key from a different CDT to another one

aswinb608 — Mon, 21 Mar 2016 20:37:03 GMT

Hi Philb,

Due to security constraints on the project I am not able to attach the xsd but I can provide a section of the code in a genralized format where the problem is occuring....here's the section:

<xsd:element name="subCDT" nillable="true" type="tns:subCDTType">
<xsd:annotation>
<xsd:appinfo source="appian.jpa">@Id @OneToOne @Column(name="foriegn_composite_key_to_sub", columnDefinition="NUMBER(10,0)")</xsd:appinfo>
</xsd:annotation>
</xsd:element>

The subCDT has two columns which pairs up to form a composite key and "foriegn_composite_key_to_sub" represents that pair....

RE: Hi,
I am trying to map a composite key from a different CDT to another one

Jacob Cohen - Project Leader - Macedon Technologies — Mon, 21 Mar 2016 20:10:28 GMT

As stated in the documentation, "The Query Database Smart Service can read from and write to tables with composite keys." You may have to switch to that.

RE: Hi,
I am trying to map a composite key from a different CDT to another one

PhilB — Mon, 21 Mar 2016 20:02:46 GMT

@ramakg Are you able to have the table owners add a stored procedure to insert to that table? You could then call that instead of doing a direct database write.

@aswinb608 Are you able to attach your XSD?

RE: Hi,
I am trying to map a composite key from a different CDT to another one

aswinb608 — Mon, 21 Mar 2016 19:55:48 GMT

I am getting an error when declaring additional variables in that cdt with @Id representing foriegn key to that composite key table...see attached...

RE: Hi,
I am trying to map a composite key from a different CDT to another one

ramakg — Mon, 21 Mar 2016 19:45:59 GMT

sorry typo. please read done->dont

RE: Hi,
I am trying to map a composite key from a different CDT to another one

ramakg — Mon, 21 Mar 2016 19:43:31 GMT

The table is not belongs to us (which is created by some other department) and done have much control. But we have to insert the data through the Appian? Do we have any workaround solution?

RE: Hi,
I am trying to map a composite key from a different CDT to another one

PhilB — Mon, 21 Mar 2016 19:33:40 GMT

I think it's probably fair to say that Appian doesn't support composite keys.

What we've done in the past is have a view built over the table which adds a new column that provides a unique key per row - but that doesn't help much if you need to write to the table.

RE: Hi,
I am trying to map a composite key from a different CDT to another one

Jacob Cohen - Project Leader - Macedon Technologies — Mon, 21 Mar 2016 19:24:57 GMT

Here is the documentation on composite keys: forum.appian.com/.../Database_Schema_Best_Practices.html

RE: Hi,
I am trying to map a composite key from a different CDT to another one

ramakg — Mon, 21 Mar 2016 18:48:10 GMT

We are also having similar requirement. The database table contains the composite primary key (on 2keys). How to define a composite primary key in cdt?

Hi, I am trying to map a composite key from a different CDT to another one

RE: Hi, I am trying to map a composite key from a different CDT to another one

RE: Hi, I am trying to map a composite key from a different CDT to another one

RE: Hi,I am trying to map a composite key from a different CDT to another one

RE: Hi,I am trying to map a composite key from a different CDT to another one

RE: Hi,I am trying to map a composite key from a different CDT to another one

RE: Hi,I am trying to map a composite key from a different CDT to another one

RE: Hi,I am trying to map a composite key from a different CDT to another one

RE: Hi,I am trying to map a composite key from a different CDT to another one

RE: Hi,I am trying to map a composite key from a different CDT to another one

RE: Hi,I am trying to map a composite key from a different CDT to another one

RE: Hi,I am trying to map a composite key from a different CDT to another one

RE: Hi,I am trying to map a composite key from a different CDT to another one

RE: Hi,I am trying to map a composite key from a different CDT to another one

RE: Hi,I am trying to map a composite key from a different CDT to another one

RE: Hi,I am trying to map a composite key from a different CDT to another one

RE: Hi,I am trying to map a composite key from a different CDT to another one

RE: Hi,I am trying to map a composite key from a different CDT to another one

RE: Hi,I am trying to map a composite key from a different CDT to another one

RE: Hi,
I am trying to map a composite key from a different CDT to another one

RE: Hi,
I am trying to map a composite key from a different CDT to another one

RE: Hi,
I am trying to map a composite key from a different CDT to another one

RE: Hi,
I am trying to map a composite key from a different CDT to another one

RE: Hi,
I am trying to map a composite key from a different CDT to another one

RE: Hi,
I am trying to map a composite key from a different CDT to another one

RE: Hi,
I am trying to map a composite key from a different CDT to another one

RE: Hi,
I am trying to map a composite key from a different CDT to another one

RE: Hi,
I am trying to map a composite key from a different CDT to another one

RE: Hi,
I am trying to map a composite key from a different CDT to another one

RE: Hi,
I am trying to map a composite key from a different CDT to another one

RE: Hi,
I am trying to map a composite key from a different CDT to another one

RE: Hi,
I am trying to map a composite key from a different CDT to another one

RE: Hi,
I am trying to map a composite key from a different CDT to another one

RE: Hi,
I am trying to map a composite key from a different CDT to another one

RE: Hi,
I am trying to map a composite key from a different CDT to another one