Recital

Login Register

In this article Barry Mavin, CEO and Chief Software Architect for Recital, details how to use the Client Drivers provided with the Recital Database Server to work with local or remote server-side OLE DB data sources.

Overview

The Recital Universal .NET Data Provider provides connectivity to the Recital Database Server running on any supported platform (Windows, Linux, Unix, OpenVMS) using the RecitalConnection object.

The Recital Universal JDBC Driver provides the same functionality for java applications.

The Recital Universal ODBC Driver provides the same functionality for applications that use ODBC.

Each of the above Client Drivers use a connection string to describe connections parameters.

The basic format of a connection string consists of a series of keyword/value pairs separated by semicolons. The equal sign (=) connects each keyword and its value.

The following table lists the valid names for keyword/values.


Name Default Description

Data Source
-or-
Server
-or-
Nodename

 

  The name or network address of the instance of the Recital Database Server which to connect to.
Directory   The target directory on the remote server where data to be accessed resides. This is ignored when a Database is specified.

Encrypt
-or-
Encryption

false When true, DES3 encryption is used for all data sent between the client and server.
Initial Catalog
-or-
Database
  The name of the database on the remote server.
Password
-or-
Pwd
  The password used to authenticate access to the remote server.
User ID   The user name used to authenticate access to the remote server.

Connection Pooling
-or-
Pool

false Enable connection pooling to the server. This provides for one connection to be shared.
Logging false Provides for the ability to log all server requests for debugging purposes
Rowid true When Rowid is true (the default) a column will be post-fixed to each SELECT query that is a unique row identifier. This is used to provide optimised UPDATE and DELETE operations. If you use the RecitalSqlGrid, RecitalSqlForm, or RecitalSqlGridForm components then this column is not visible but is used to handle updates to the underlying data source.
Logfile   The name of the logfile for logging
Gateway  

Opens an SQL gateway(Connection) to a foreign SQL data source on the remote server.

Using Gateways, you can transparently access the following local or remote data sources:

  • Recital
  • Oracle
  • ODBC (Server-side ODBC data sources)
  • JDBC (Server-side JDBC data sources)
  • ADO (Use this to connect to SQL Server and other Native Windows OLEDB data sources)
  • MySQL
  • PostgreSQL

The gateway can be specified in several formats:

servertype@nodename:username/password-database

e.g.

oracle@nodename:username/password-database

mysql@nodename:username/password-database

postgresql@nodename:username/password-database

-or-

odbc:odbc_data_source_name_on_server

oledb:oledb_connection_string_on_server

jdbc:jdbc_driver_path_on_server;jdbc:Recital:args


To connect to a server-side OLE DB data source, you use the gateway=value key/value pair in the following way.

gateway=oledb:oledb_connection_string_on_server

Important
When specifying the connection string be sure to quote the gateway= with "...".

You can find examples of connection strings for most ODBC and OLE DB data sources by clicking here.

Example in C# using the Recital Universal .NET Data Provider:
////////////////////////////////////////////////////////////////////////
// include the references below
using System.Data;
using Recital.Data;
 
////////////////////////////////////////////////////////////////////////
// The following code example creates an instance of a DataAdapter that 
// uses a Connection to the Recital Database Server, and a gateway to
// the SQL server Northwind database. It then populates a DataTable 
// in a DataSet with the list of customers. The SQL statement and 
// Connection arguments passed to the DataAdapter constructor are used 
// to create the SelectCommand property of the DataAdapter.
public DataSet SelectCustomers()
{
	string gateway = "oledb:Provider=sqloledb;Initial Catalog=Northwind;
		Data Source=localhost;Integrated Security=SSPI";
	RecitalConnection swindConn = new 
		RecitalConnection("Data Source=localhost;gateway=\""+gateway+"\");
	RecitalCommand selectCMD = new 
		RecitalCommand("SELECT CustomerID, CompanyName FROM Customers", swindConn);
	selectCMD.CommandTimeout = 30;
	RecitalDataAdapter custDA = new RecitalDataAdapter();
	custDA.SelectCommand = selectCMD;
	swindConn.Open();
	DataSet custDS = new DataSet();
	custDA.Fill(custDS, "Customers");
	swindConn.Close();
	return custDS;
}
Example in Java using the Recital Universal JDBC Driver:
////////////////////////////////////////////////////////////////////////
// standard imports required by the JDBC driver
import java.sql.*;
import java.io.*;
import java.net.URL;
import java.math.BigDecimal;
import Recital.sql.*;
 
////////////////////////////////////////////////////////////////////////
// The following code example creates a Connection to the Recital 
// Database Server, and a gateway to the SQL server Northwind database. 
// It then retrieves all the customers.
public void SelectCustomers()
{
    // setup the Connection URL for JDBC
	String gateway = "oledb:Provider=sqloledb;Initial Catalog=Northwind;
		Data Source=localhost;Integrated Security=SSPI";
	String url = "jdbc:Recital:Data Source=localhost;gateway=\""+gateway+"\";
	// load the Recital Universal JDBC Driver
	new RecitalDriver();
 
	// create the connection
	Connection con = DriverManager.getConnection(url);
	// create the statement
	Statement stmt = con.createStatement();
	// perform the SQL query
	ResultSet rs = stmt.executeQuery("SELECT CustomerID, CompanyName FROM Customers");
	// fetch the data
	while (rs.next()) 
	{
		String CompanyID = rs.getString("CustomerID");
		String CompanyName = rs.getString("CompanyName");
		// do something with the data...
	}
    
	// Release the statement
	stmt.close();
	
	// Disconnect from the server
	con.close();
}
Published in Blogs
Read more...
Each Recital table can have one or more data dictionaries to provide a central repository for constraints and other metadata. 

Here's how to set up field validation for a field with a small static number of acceptable values.

Using the example.dbf table from the southwind sample database, validation can be added to the title field to ensure it matches one of a list values.
open database southwind
alter table example add constraint;
(title set check inlist(alltrim(title),"Miss","Mr","Mrs","Ms"))
The inlist() function checks whether the specified expression exists in the comma-separated list which follows.  An attempt to update title with a value not in the list will give an error: Validation on field 'TITLE' failed.

If you have access to the Recital Workbench, you can use the modify structure worksurface to add and alter your dictionary entries, including a customized error message if required.

validation


Published in Blogs
Read more...

 
Key features of the Recital database include:

  • SQL-92 and a broad subset of ANSI SQL 99, as well as extensions
  • Cross-platform support
  • Stored procedures
  • Triggers
  • Cursors
  • Updatable Views
  • System Tables
  • Query caching
  • High-performance
  • Single-User and Multi-User
  • Multi-Process
  • ACID Transactions
  • Referential Integrity
  • Cascading Updates and Deletes
  • Multi-table Joins
  • Row-level Locking
  • BLOBs (Binary Large Objects)
  • UDFs (User Defined Functions)
  • OLTP (On-Line Transaction Processing)
  • Drivers for ODBC, JDBC, and .NET
  • Sub-SELECTs (i.e. nested SELECTs)
  • Embedded database library
  • Database timelines providing data undo functionality
  • Fault tolerant clustering support
  • Hot backup
Published in Blogs
Read more...
Recital 10 introduced the ECHO command. This command operates in the same way as the PHP ECHO command. It does not append a newline to the output but rather operates in the same way as the existing ?? command in Recital. The string being output can contain C-style string escapes \n \t or \r (newline, tab and carriage return respectively) e.g.
echo "Hello world\n"
Published in Blogs
Read more...
Recital 10 introduced the REQUIRE() and REQUIRE_ONCE() statement.

The REQUIRE() statement includes and executes the contents of the specified file at the current program execution level.

When a file is included, the code it contains inherits the variable scope of the line on which the include occurs. Any variables, procedures, functions or classes declared in the included file will be available at the current program execution level.

The REQUIRE_ONCE() statement is identical to the REQUIRE() statement except that Recital will check to see if the file as already been included and if so ignore the command.

The full syntax is:
REQUIRE( expC )
REQUIRE_ONCE( expC )

e.g.

REQUIRE_ONCE( "myapp/myglobals.prg" )
Published in Blogs
Read more...

This guide will assist you in setting up an rsnapshot backup server on your network. rsnapshot uses rsync via ssh to perform unattended backups of multiple systems in your network. The guide can be found on the centos website here.

Published in Blogs
Read more...
Found a nice subversion plugin for finder on the MAC.

The goal of the SCPlugin project is to integrate Subversion into the Mac OS X Finder. 

  • Support for Subversion.
  • Access to commonly used source control operations via contextual menu [screenshot]
  • Dynamic icon badging for files under version control. Shows the status of your files visually. [ screenshot ]
Published in Blogs
Read more...
By default Recital uses PAM to authenticate users.  It is also possible to tell PAM to use Kerberos.  Simply replace the existing entries in the /etc/pam.d/recital file with the ones below:

auth       sufficient   pam_krb5.so try_first_pass
auth       sufficient   pam_unix.so shadow nullok try_first_pass
account    required     pam_unix.so broken_shadow
account    [default=bad success=ok user_unknown=ignore] pam_krb5.so
Published in Blogs
Read more...

If you want details about how storage devices are performing on Redhat/Centos/Fedora use the vmstat and iostat commands.

After installing Centos 5.3 the iostat command is not available. To install it use yum:

# yum install sysstat
Published in Blogs
Read more...
The Komodo Editor is a free project based editor that runs on the mac, linux and windows. It color codes and handles auto completion for lots of languages (including Recital/PHP/Perl/C etc). You can download it free from here.
Published in Blogs
Read more...
Twitter

Copyright © 2019 Recital Software Inc.

Login

Register

User Registration
or Cancel