Library: Interfaces, Database access (OMDB) Import: omdb.xmd

Declaration

  define  external function db.execute
           value       db.procedure procedure
    in     read-only   stream       inshelf   optional
    null   value       stream       null      optional
    out    modifiable  db.field     outshelf  optional
    result modifiable  db.field     result    optional

  or

  define external function db.execute
           value       db.statement statement
     with  read-only   stream      values    optional
     null  value       stream      null      optional
     into  modifiable  db.field     record    optional

Argument definitions

procedure

is the db.procedure object associated with an open procedure.

inshelf

is a shelf of stream items that contain the input and inout parameter values.

null

is a string, rather than an unattached stream, to represent a NULL value in the input parameter values.

outshelf

is a shelf of db.field items to receive output and inout parameter values, and the function procedure return.

result

is a db.field shelf attached to the attached to the result set for any SQL query executed.

statement

is a compiled db.statement object.

values

is a shelf containing the parameter data.

null

is an optional string representing null values.

record

is a shelf of db.field items bound to result set fields.

Executing a Stored Procedure

The database where the procedure is stored must be:

• open (else external exception OMDB104)
• in scope (else external exception OMDB103)

procedure must:

• exist (else external exception OMDB402)
• have a name (else external exception OMDB408)
• be open for processing requests (else external exception OMDB405)

• have an item for every input parameter (else external exception OMDB407)
• contain valid data (else external exception OMDB501)

At the beginning of the function, the output shelf is cleared and filled with db.field items attached to the output and inout (combined input and output) procedure parameters. The input shelf items are sequentially matched to the procedure input parameters by position. You can represent NULL values in the input shelf item by an optional null specifier string or as an unattached stream.

The result shelf can contain multiple records. The input and output shelves can only contain a single record.

The result shelf is cleared in the function. If the procedure returns a result set the result shelf is filled with db.field items attached to the result set. The data value is extracted from the output and return parameters in a subsequent call to the db.reader function.

The output and result db.field field items are keyed with the name of the procedure parameter, if one exists.

If a record used by the procedure has a date, time, or timestamp field, you must represent the field's value in the OmniMark Date and Time library format. (This format returns the time with a time zone offset from UTC time, which most databases do not provide.)

Executing a Compiled SQL Statement

Use db.execute to execute a compiled SQL statement that was produced by the db.compile-statement function.

The db.database object supplied when the statement was compiled must be open (else external exception OMDB101).

The db.statement object statement must be open (else external exception OMDB701).

If the db.statement object is a compiled query, it requires the db.field shelf argument record to receive the results (else external exception OMDB704).

The input shelf values must:

• contain the parameters required by the compiled statement (else external exception OMDB702).
• contain the correct number of parameters (else external exception OMDB703).
• contain the correct size of parameters (else external exception OMDB704).

db.execute allows you to execute a compiled statement and to specify all the parameter values at once. This is more efficient for small parameters.

For large parameters (for example, db.blob-type types) when there is a large amount of data to be inserted, it is more efficient to use the db.streaming-execute function, as that avoids creating an entire copy of the data in memory prior to execution.

See db.compile-statement for additional notes and examples.

Related Syntax    db.database    db.open-procedure    dbProcedureClose    db.procedure

Related Concepts    Using the OMDB library

Other Library Functions    db.advance-recordset    db.close    db.commit    db.compile-statement    db.database    db.delete    db.discard    db.execute    db.execute-in    db.field    db.insert    db.move-record    db.omdb-version    db.omdb-version-oci8    db.omdb-version-oci8i    db.omdb-version-odbc    db.open-oci8    db.open-oci8i    db.open-odbc    db.open-procedure    db.open-table    db.prepare    db.procedure    db.query    db.reader    db.record-exists    db.rollback    db.set-transaction-type    db.statement    db.streaming-execute    db.table    db.update    db.writer

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