In this article Yvonne Milne looks at the use of the Recital Remote Data Connectivity Functions with Recital Database Gateways.
SET DATADIR TO [ <directory> ]This command is used to specify a directory where database tables, memos, indexes, and dictionary files are located. When a table is being opened this directory is searched first before the current directory and the file search path to locate the table and its associated files. This allows the database tables to be relocated to a different file system without the need to change an existing application.
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" )
In this article Barry Mavin, CEO and Chief Software Architect for Recital, details on how to use the Client Drivers provided with the Recital Database Server to work with local or remote server-side JDBC 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 equals sign (=) connects each keyword and its value.
The following table lists the valid names for keyword/values.
Name | Default | Description |
---|---|---|
Data Source |
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 |
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 |
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.
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 JDBC data source, you ue the gateway=value key/value pair in the following way.
gateway=jdbc:jdbc_driver_path_on_server;jdbc:Recital:args
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 // Recital Southwind database. It then populates a DataTable // in a DataSet with the list of customers via the JDBC driver. // 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 = "jdbc:/usr/java/lib/RecitalJDBC/Recital/sql/RecitalDriver;"+ "jdbc:Recital:Data Source=localhost;database=southwind"; 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 Recital Southwind database. // It then retrieves all the customers via the JDBC driver. public void SelectCustomers() { // setup the Connection URL for JDBC String gateway = "jdbc:/usr/java/lib/RecitalJDBC/Recital/sql/RecitalDriver;"+ "jdbc:Recital:Data Source=localhost;database=southwind"; 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(); }
// the click event handler private function onclick_sourcetree(e:Event):void { yourTree.editable = false; } // the doubleclick event handler private function ondoubleclick_sourcetree(e:Event):void { yourTree.editable = true; yourTree.editedItemPosition = {columnIndex:0, rowIndex:sourceTree.selectedIndex}; }
APPEND FROM TYPE CSV <file-name.csv>The TYPE keyword has now been enhanced to support a comma separated values (CSV) format
We are pleased to announce the release of Recital 10.0.2.
Here is a brief list of features and functionality that you will find in the 10.0.2 release.
- New commands
SAVE/RESTORE DATASESSION [TO variable]
CONNECT "connectString"
DISCONNECT - New functions (OData compatible)
startsWith(haystack as character, needle as character)
endsWith(haystack as character, needle as character)
indexOf(haystack as character, needle as character)
substringOf(haystack as character, needle as character)
concat(expC1, expC2) - New system variables
_LASTINSERTEDSYNCNUM - Enhanced commands
Added CONNSTRING "connectingString" to the USE command to connect to remote servers (Recital, MySQL, PostgreSQL, Oracle, ODBC) - Further SQL query optimizer improvements to boost performance
- Performance improvements in Recital Web
- Forced all temporary files into temp directory (improves performance when local tmpfs is used as temp directory and reduces network i/o)
- Fixed cookie and session variable problems in Recital Web
- Fixed problem with temporary files being left after some server queries involving memos and object data types
- Improved performance of the Windows ODBC driver
- Fixed a security flaw in Recital Web
- Fixed all reported bugs
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(); }
The Openfiler NAS/SAN Appliance (NSA) is a Storage Management Operating System / NAS Appliance distribution. It is powered by the Linux 2.6 kernel and Open Source applications such as Apache, Samba, LVM2, ext3, Linux NFS and iSCSI Enterprise Target. Openfiler combines these ubiquitous technologies into a small, easy to manage solution fronted by a powerful web-based management interface. Openfiler allows you to build a Network Attached Storage (NAS) and/or Storage Area Network (SAN) appliance, using industry-standard hardware, in less than 10 minutes of installation time.
Building upon the popularity of server virtualization technologies such as VMware, Virtual Iron, and Xen, Openfiler can also be deployed as a virtual machine instance or on a bare metal machine.
This deployment flexibility of Openfiler ensures that storage administrators are able to make the best use of system performance and storage capacity resources when allocating and managing networked storage in a multi-platform environment.
Openfiler is ideally suited for use with High Availability Recital applications as it incorporates:
- Heartbeat cluster manager
- drbd disk replication
- CIFS
- NFS
- Software and hardware RAID
- FTP
- rsync
- HTTP/DAV
- iSCSI
- LVM2
- Multiple NIC bonding for High Availability
- Powerful web-based GUI
http://msdn.microsoft.com/en-us/library/cc351024(VS.85).aspx