Pseudo-columns
This article is about pseudo-columns as part of the SQL syntax that USoft supports.
Pseudo-columns
A pseudo-column is an expression that you can use in the SELECT list of a SQL statement as if it were a column name, but that does not refer to a physical column in a table.
You can use pseudo-columns in SELECT output lists but also as the value of certain attributes in USoft Definer, in particular, in the Default Value attribute of Columns and Domains.
| Pseudo-column | Description |
|---|---|
| ROWNUM | The sequence number of a given record in a query result set. |
| SYSDATE | The current server date. SYSDATE is Oracle-only. For portability to other platforms, use $$CURRENTDATE$$ or the CURRENT_DATE SQL function instead. |
| $$CURRENTDATE$$ | The current server date. |
| $$CURRENTDATETIME$$ | The current server date and time. |
| $$GUID$$ | A generated GUID, same result as the GUID() SQL function. |
| $$TRANSACTIONDATE$$ | The server date of the first time this function is processed within the transaction. |
| $$TRANSACTIONDATETIME$$ | The server date and time of the first time this function is processed within the transaction. |
| USER | The name of the USoft application user currently logged in. |
| $$RDBMSUSER$$ | The name of the user used to access the RDBMS resources. |
| $$RDBMSOWNER$$ | The name of the user who owns the RDBMS objects being accessed. |
| $$USER$$ | The name of the USoft application user currently logged in. |
Notes
Pseudo-columns are similar to SQL functions that take no arguments, such as TRANSACTION_DATE(). They differ from such functions in that the call syntax does not use empty parentheses ():
SELECT USER
SELECT $$USER$$
SELECT TRANSACTION_DATE()
Another difference is that you can use a pseudo-column, but not a SQL function, as the Default Value attribute of a Column or Domain.