HDBSequence
Overview
The information on this page will help you lesrn how to develop the design-time data-persistence model for an XSK application using the HDBSequence syntax.
Reference
SAP Help Portal
- SAP HANA XS Classic: For more information, see Create a Sequence.
- SAP HANA XS Advanced: For more information, see CREATE SEQUENCE Statement (Data Definition).
Sample
schema= "TEST_DUMMY";
start_with= 10;
maxvalue= 30;
nomaxvalue=false;
minvalue= 1;
nominvalue=true;
cycles= false;
reset_by= "SELECT T1.\"Column2\" FROM \"MYSCHEMA\".\"com.acme.test.tables::MY_TABLE1\" AS T1 LEFT JOIN \"MYSCHEMA\".\"com.acme.test.tables::MY_TABLE2\" AS T2 ON T1.\"Column1\" = T2.\"Column1\"";
depends_on=["com.acme.test.tables::MY_TABLE1", "com.acme.test.tables::MY_TABLE2"];
SEQUENCE "com.sap.hana.example::CUSTOMER_ID"
RESET BY
SELECT IFNULL(MAX(ID), 0) + 1 FROM "com.sap.hana.example::CUSTOMERS"
Configuration Schema
| Name | Description | Type | Default value | Required |
|---|---|---|---|---|
| schema | Name of the schema that contains the sequence you are defining. | String | None | Yes |
| increment_by | Specifies that the sequence increments by a defined value. | Integer | 1 | No |
| start_with | Specifies that the sequence starts with a specific value. Cannot be less than the minimum value. | Integer | 1 | No |
| maxvalue | Specifies that the sequence stops at a specific maximum value. | Integer | Different for each DB | No |
| nomaxvalue | Specifies that the sequence does not stop at any specific maximum value. | Boolean | False | No |
| minvalue | Specifies that the sequence stops at a specific minimum value. | Integer | 1 | No |
| nominvalue | Specifies that the sequence does not stop at any specific minimum value. | Boolean | False | No |
| cycles | Enables you to specify whether the sequence number will be restarted after it reaches its maximum or minimum value. | Boolean | None | No |
| reset_by | Enables you to reset the sequence using a query on any view, table or even table function. However, any dependency must be declared explicitly, for example, with the depends_on_view or depends_on_table keyword. If the table or view specified in the dependency does not exist, the activation of the sequence object in the repository fails. | String | None | No |
| public | Specifies if it is public or not. | Boolean | False | No |
| depends_on_table | Enables you to define a dependency to one or more specific tables. | List(String) | None | No |
| depends_on_view | Enables you to define a dependency to one or more specific views. | List(String) | None | No |
| depends_on | Enables you to define a dependency to one or more specific tables or views, for example, when using the reset_by option to specify the query to use when resetting the sequence. | List(String) | None | No |
Caution
Reserved keywords, used as table or column names in queries, must be escaped.