In this article Barry Mavin, CEO and Chief Software Architect for Recital, details Working with Stored Procedures in the Recital Database Server.

Overview

Stored procedures and user-defined functions are collections of SQL statements and optional control-of-flow statements written in the Recital 4GL (compatible with VFP) stored under a name and saved in a Database. Both stored procedures and user-defined functions are just-in-time compiled by the Recital database engine. Using the Database Administrator in Recital Enterprise Studio, you can easily create, view, modify, and test Stored Procedures, Triggers, and user-defined functions

Creating and Editing Stored Procedures

To create a new Stored Procedure,  right-click the Procedures node in the Databases tree of the Project Explorer and choose Create. To modify an existing stored procedure select the Stored Procedure in the Databases Tree in the Project Explorer by double-clicking on it or selecting Modify from the context menu . By convertion we recommend that you name your Stored Procedures beginning with "sp_xxx_", user-defined functions with "f_xxx_", and Triggers with "dt_xxx_", where xxx is the name of the table that they are associated with.

Testing the Procedure

To test run the Stored Procedure, select the Stored Procedure in the Databases Tree in the Project Explorer by double-clicking on it. Once the Database Administrator is displayed, click the Run button to run the procedure.

Getting return values

Example Stored Procedure called "sp_myproc":

parameter arg1, arg2
return arg1 + arg2

Example calling the Stored Procedure from C# .NET:

////////////////////////////////////////////////////////////////////////
// include the references below
using System.Data;
using Recital.Data;

////////////////////////////////////////////////////////////////////////
// sample code to call a Stored Procedure that adds to numeric values together
public int CallStoredProcedure()
{
	RecitalConnection conn = new 
		RecitalConnection("Data Source=localhost;Database=southwind;uid=?;pwd=?");
	RecitalCommand cmd = new RecitalCommand();
	cmd.Connection = conn;
	cmd.CommandText = "sp_myproc(@arg1, @arg2)";
	cmd.CommandType = CommandType.StoredProcedure;
	cmd.Parameters["@arg1"].Value = 10;
	cmd.Parameters["@arg2"].Value = 20;
	conn.Open();
	cmd.ExecuteNonQuery();
	int result = (int)(cmd.Parameters["retvalue"].Value);    // get the return value from the sp
	conn.Close();
	return result;
	}

Writing Stored Procedures that return a Resultset

If you want to write a Stored Procedure that returns a ResultSet, you use the SETRESULTSET() function of the 4GL. Using the Universal .NET Data Provider, you can then execute the 4GL Stored Procedure and return the ResultSet to the client application for processing. ResultSets that are returned from Stored Procedures are read-only.

Example Stored Procedure called "sp_myproc":

parameter query
select * from customers &query into cursor "mydata"
return setresultset("mydata")

Example calling the Stored Procedure from C# .NET:

////////////////////////////////////////////////////////////////////////
// include the references below
using System.Data;
using Recital.Data;

////////////////////////////////////////////////////////////////////////
// sample code to call a stored procedure that returns a ResultSet
public void CallStoredProcedure()
{
	RecitalConnection conn = new 
		RecitalConnection("Data Source=localhost;Database=southwind;uid=?;pwd=?");
	RecitalCommand cmd = new RecitalCommand();
	cmd.Connection = conn;
	cmd.CommandText = "sp_myproc(@query)";
	cmd.CommandType = CommandType.StoredProcedure;
	cmd.Parameters["@query"].Value = "where not deleted()";
	conn.Open();
	RecitalDataReader dreader = cmd.ExecuteReader();
	int sqlcnt = (int)(cmd.Parameters["sqlcnt"].Value);    // returns number of affected rows
	while (dreader.Read())
	{
		// read and process the data
	}
	dreader.Close();
	conn.Close();
}