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Nearly every command in the Omnidex SQL library supports the ON CURSOR
n or ON INSTANCE n clause to allow Omnidex applications to make use of
multiple cursors. This clause is appended to the end of an SQL statement,
but before the optional WITH options statement.
In ODXSQL, use the CURSORDISPLAY ON set option to automatically display
the current cursor and instance numbers.
>SET CURSORDISPLAY ON
>connect /users/garment.env
Connected to /users/garment.env on instance 2, cursor 2
>SELECT COMPANY, CONTACT, PHONE FROM CUSTOMERS WHERE STATE='CO'
ON CURSOR 2
The ON CURSOR n clause is optional. If it is not specified, the SQL statement
will be executed on the current cursor defined in the cursor parameter
of the status array.
The ON INSTANCE n clause can only be used by statements that do not require
a cursor to be open. This includes statements like INSERT, INSERTINDEX,
and many more. See the individual statement definitions for information
on whether the statement uses an instance or a cursor. If omitted, the
SQL statement will be executed on the instance owning the cursor passed
in the cursor parameter of oaexecsql or in the instance member of the
status array.
 Each
individual JDBC Statement object and ODBC CLI HSTMT objects are created
on their own cursors. Likewise, each Connection object in both types of
applications are created on their own instances. Therefore, the use of
the ON CURSOR and ON INSTANCE clauses is unnecessary. To switch between
multiple cursors or instances, simply reference the appropriate object.
Syntax
statement [ON [CURSOR] n | [INSTANCE] n] [WITH options]
statement
Required. Any valid SQL statement supported by Omnidex.
ON
Required if specifying the cursor or instance number. Omit if using the
default current cursor or instance.
[CURSOR | INSTANCE]
Optional. The CURSOR and INSTANCE keywords are optional.
n
Required if specifying the cursor or instance number. Omit if using the
default current cursor or instance. This is the cursor or instance number
that the current command will be executed on. Cursors and instances are
numbered automatically as they are created. In OdxSQL, use the CURSORDISPLAY
ON set option to automatically display the current cursor and instance
numbers.
[WITH options]
Optional. A comma separated list of options to use for the current statement.
ODXSQL Example
>SET CURSORDISPLAY ON
>connect /users/garment.env
Connected to /users/garment.env on instance 1, cursor 1
>connect / users/orders.env
Connected to /users/orders.env on instance 2, cursor 2
SELECT COMPANY, CONTACT, PHONE FROM CUSTOMERS WHERE STATE='CO'
ON CURSOR 2
...
INSERT INTO CUSTOMERS (COMPANY, CONTACT) VALUES ('New Wave',
'Mr. Smith') ON CURSOR 1
...
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