OpenEdge Data Management: DataServer for Microsoft SQL Server

Interfacing with RDBMS stored procedures
Note: The ABL QUOTER function can be useful for quoting values or handling
embedded quotes when building SQL statements that will be passed into
stored procedures with the send-sql-statement option.
Assessing result sets obtained from the proc-text-buffer technique
The advantage of using the proc–text–buffer is that you do not have to worry about
what kind of data the procedure returns. The buffer accepts any type of data, in any
order, and converts it to the character equivalent. Another benefit of the
proc–text–buffer is that it can be used to hold the results from all of the SQL
statements included in a stored procedure. However, a buffer that you create can hold
the results of only one results set record form one result set at a time.
However, a disadvantage in using the proc-text-buffer technique is that it is much
more difficult to manipulate the data after you receive it as it requires parsing the data.
To act on anything but CHARACTER data, you must extract the data from the buffer and
convert it to its original data type before you can use it.
Defining a view to use as a buffer
As an alternative to using the OpenEdge buffer proc–text–buffer definition, you can
define a view in the data source that can serve as a buffer allowing you to retrieve
database results in their original data types. However, keep in mind that using views
creates a database dependency beyond the stored procedure itself.
Technique to define a view to use as a buffer
While a stored procedure can include multiple SQL statements, a buffer that you define
contains the format of only a single results set. You need to define multiple views to
accommodate multiple results sets.
To define a buffer:
1. Define a view in the MS SQL Server data source with the following characteristics:
• The naming convention _BUFFER_buffername
• The same number of columns and data types that the stored procedure
returns in the results set
• The columns in the order that the stored procedure returns them
For example, to return two columns with two types of values, an integer and a
character string, use a SQL utility to define the following view in the data source:
CREATE VIEW _BUFFER_custlist AS SELECT customer.cust_num,
customer.name FROM customer WHERE 1 = 0
GO
Notice that these views are defined to ensure that they never return any results.
This helps to indicate that the purpose of the view is its buffer content and not its
SQL capabilities. It is not necessary to define views that you will use as buffers
this way, but it does allow you to distinguish quickly between views and buffers.
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