1  DECLARE_STREAM
   Declares a stream and is thereby able to associate a stream name
   with its RSE. This provides Oracle Rdb with the context needed
   to place the elements of the START_STREAM...FETCH...END_STREAM
   construct across a programming module in any order.

   Example:

   DECLARE_STREAM CURRENT_INFO_STREAM USING
     CI IN CURRENT_INFO SORTED BY DESCENDING CI.SALARY
 

2  More
   If you have invoked a database, you have the necessary privileges
   to use the DECLARE_STREAM statement.

   Use the DECLARE_STREAM statement in conjunction with the declared
   START_STREAM statement. The DECLARE_STREAM statement will not
   work in conjunction with the undeclared START_STREAM statement.

   Rdb recommends that all programs use the DECLARE_STREAM statement 
   (with the declared START_STREAM statement) instead of the undeclared 
   START_STREAM statement. The declared START_STREAM statement provides 
   all the functions of the undeclared START_STREAM statement and 
   provides more flexibility in programming than the undeclared 
   START_STREAM statement.

   Put the DECLARE_STREAM statement before the associated declared
   START_STREAM, FETCH, and END_STREAM statements.

   The DECLARE_STREAM statement allows the use of fewer or more
   END_STREAM statements than START_STREAM statements within the
   same module, as long as at execution time exactly one END_STREAM
   statement is executed for each START_STREAM statement.

   RDO does not allow a record stream from which data values cannot be
   fetched by DBKEY (views that retrieve values from streams defined using
   the SQL GROUP BY or UNION clauses) to be declared or started. Such
   attempts produce the following exception:

     VWNOFETCH view 'view-name' cannot be fetched within a stream
 

2  Format

 (B)0DECLARE_STREAM  qwqqqqqqqqqqq>qqqqqqqqqwq> declared-stream-name qk
                  mqq> handle-options qqj                         x
 lqqqqqqqqqqqqqqqqqqqqqqqqqq<qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqj
 mqqqqqqqqqqqqqqqqqq> USING qqqqqqqqqq> rse qqqqqqqqqqqqqqqqqqqqqq>

 

3  handle-options

 (B)0handle-options =
 
 qq> ( qwq> REQUEST_HANDLE qqq> var qqqqqqqqqqqqqqqqqqqqqqqqqqqwq> ) qq>
        tq> TRANSACTION_HANDLE qqq> var qqqqqqqqqqqqqqqqqqqqqqqu
        mq> REQUEST_HANDLE q> var , TRANSACTION_HANDLE q> var qj

 

4  REQUEST_HANDLE
   A keyword followed by a host language variable. A request handle
   points to the location of a compiled Oracle Rdb request. If you
   do not supply a request handle explicitly, Oracle Rdb associates a
   default request handle with the compiled request. You must use
   a request handle when you want to make an identical query to two
   different databases.

   In Callable RDO, use !VAL as a marker for host language
   variables.

   You can put parentheses around the host language variable name.
 

4  TRANSACTION_HANDLE
   A keyword followed by a host language variable. A transaction
   handle identifies each instance of a transaction. If you do not
   declare the transaction handle explicitly, Oracle Rdb attaches an
   internal identifier to the transaction.

   In Callable RDO, use !VAL as a marker for host language
   variables.

   You can put parentheses around the host language variable name.

   Normally, you do not need to use this argument. The ability to
   declare a transaction handle is provided for compatibility with
   other database products and future releases of Oracle Rdb.
 

3  declared-stream-name
   A name you give to the stream you declare. The stream name must
   be a valid OpenVMS name.
 

3  rse
   A record selection expression. A phrase that defines the specific
   conditions that individual records must meet before Oracle Rdb
   includes them in a record stream.
 

2  Example
   The following example declares a record stream named EMP_STREAM
   in RDO:

   RDO>  DECLARE_STREAM EMP_STREAM USING
   cont>   E IN EMPLOYEES SORTED BY E.LAST_NAME, E.FIRST_NAME