Working with server-side OLE DB data sources

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

Using Recital with PHP

This article describes how to use Recital with PHP.

Published in Blogs

FIX: ssh: Connection closed by remote host

When stress testing our loadbalancer, i was unable to get more than 20 reliable ssh connections. The following error would be reported.

ssh_exchange_identification: Connection closed by remote host

The resolution for this is quite simple.

Edit the /etc/ssh/sshd_config file and increase the MaxStartups. On my server i set this to 200.

Edit /etc/sysctrl.conf and add the following line:

net.core.netdev_max_backlog = 3000

Then apply this change:

# sysctl -p

Published in Blogs

Working with Stored Procedures in the Recital Database Server

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();
}

Published in Blogs

Save and restore state across Recital Web pages

When using Recital Web you can maintain the exact state of each cursor between pages like this.

On entry to the .rsp page.

IF type( _session["state"] ) != "U"
    m_state = _session["state"]
    RESTORE DATASESSION FROM m_state
ELSE
    // open up your tables for the first time 
ENDIF

On exit of the .rsp page.

SAVE DATASESSION TO m_state
_SESSION["state"] = m_state

Published in Blogs

What additional benefits does Recital provide?

Recital provides the following additional benefits:

Easy to Install and Deploy - Users can set up Recital in minutes enabling organizations to deliver new applications faster than other databases.
Easy to Administer - Recital is a low administration database that eliminates the need for highly trained, skilled, and costly database administrators to maintain the database.
High Performance - Superior database performance for the most demanding of OLTP applications. Additionally, Clustered Recital provides 99.999% availability.
Embeddable Library - Recital Embedded Edition provides in-process data storage engine that delivers all the features of a traditional relational database but in a size which makes it ideally suited for ISVs/VARs who need a small footprint and easy to use toolkit.
Platform Independence - Recital runs on Linux, Solaris, AIX, HP-UX, Windows, and Mac OS X giving organizations complete flexibility in delivering a solution on the platform of their choice.

Published in Blogs

Recital Database Security

This article discusses Recital database security: from operating system file permissions through file and field protection to DES3 encryption.

Overview

A company's data is extremely valuable and must be protected, both in operation and in physical file format. Recital products provide a range of ways to protect your data.

Operating System File Permissions

The most basic level of database security is provided by the operating system. Recital database tables and indexes are individual files with their own respective operating system file permissions. Read permission is required to open a table and write permission to update a table. If a user does not have read permission they are denied access. Without write permission, a table will be opened read-only.

Here the owner, root, and members of the recital group have write permission, so can update the example table unless additional protection applies. Other users can only open the example table read-only.

# ls -l example*
-rwxrwxr-x    1 root     recital       147 Nov 29 14:27 example.dbd
-rwxrwxr-x    1 root     recital     41580 Nov 29 14:27 example.dbf
-rwxrwxr-x    1 root     recital     13312 Nov 29 14:28 example.dbt
-rwxrwxr-x    1 root     recital     19456 Nov 29 14:28 example.dbx

Note: As in the example above, a table's associated files should have the same permissions as the table itself:

File Extension	File Type
.dbd	Dictionary
.dbf	Table
.dbt	Memo
.dbx	Index

Database Dictionary

Each Recital table may have a Database Dictionary. The Dictionary can be used both to protect the integrity of the data and to protect access to the data. This section covers Column Constraints, Triggers, Security and Protection.

Column Constraints: Data Integrity

The Dictionary attributes or constraints either prevent the entry of incorrect data, e.g. must_enter and validation or aid the entry of correct data, e.g. default, picture and choicelist. The Dictionary can be modified in the character mode CREATE/MODIFY STRUCTURE worksurface, via SQL statements, or in the Recital Enterprise Studio Database Administrator.

Click image to display full size

Fig 1: MODIFY STRUCTURE Worksurface: Dictionary.

The SQL Column Constraints are as follows:

Constraint	Description
AUTO_INCREMENT \| AUTOINC	Used to auto increment the value of a column.
CALCULATED	Used to calculate the value of a column.
CHECK \| SET CHECK	Used to validate a change to the value of a column.
DEFAULT	Used to set a default value for the specified column.
DESCRIPTION	Used set the column description for the specified column.
ERROR	Used to define an error message to be displayed when a validation check fails.
FOREIGN KEY	Used to define a column as a Foreign Key for a parent table.
NOCPTRANS	Used to prevent code page translation for character and memo fields.
NOT NULL \| NULL	Used to disallow/allow NULL values.
PRIMARY KEY	Used to define a table’s Primary Key.
RANGE	Used to specify minimum and maximum values for a date or numerical column.
RECALCULATE	Used to force recalculation of calculated columns when a column’s value changes.
REFERENCES	Used to create a relationship to an index key of another table.
UNIQUE	Used to define the column as a candidate index for the table

These can be specified in CREATE TABLE or ALTER TABLE statements:

exec sql
  OPEN DATABASE southwind;
exec sql
  ALTER TABLE customers ADD COLUMN timeref char(8) CHECK validtime(timeref)
  ERROR "Not a valid time string";

Click image to display full size

Fig 2: Database Administrator: Column Constraints and Attributes.

TRIGGERS

Table Level Triggers are event-driven procedures called before an I/O operation. These can be used to introduce another layer of checks before a particular operation is permitted to take place or to simply set up logging of those operations.

The CREATE/MODIFY STRUCTURE worksurface <TRIGGERS> menu bar option allows you to specify table level triggers. You may edit a trigger procedure from within the <TRIGGERS> menu by placing the cursor next to the procedure name and pressing the [HELP] key. A text window pops up for editing. If the table triggers are stored in separate <.prg> files, rather than in a procedure library, procedures need not be predefined (SET PROCEDURE) before using the table.

Click image to display full size

Fig 3: MODIFY STRUCTURE Worksurface: Triggers.

The following triggers can be selected and associated with a specified procedure name in the <TRIGGERS> menu.

Trigger	Description
UPDATE	The specified procedure is called prior to an update operation on the table. If the procedure returns .F., then the UPDATE is canceled.
DELETE	The specified procedure is called prior to a delete operation on the table. If the procedure returns .F., then the DELETE is canceled.
APPEND	The specified procedure is called prior to an append operation on the table. If the procedure returns .F., then the APPEND is canceled.
OPEN	The specified procedure is called after an open operation on the table.
CLOSE	The specified procedure is called prior to a close operation on the table.
ROLLBACK	The specified procedure is called when a user presses the [ABANDON] key in a forms based operation.

The Recital Enterprise Studio Database Administrator also allows you to associate existing programs as Table Trigger Procedures.

Click image to display full size

Fig 4: Database Administrator: Triggers.

Programmatically, Trigger Procedures can also be associated with a table using SQL. The following table constraints may be applied in the SQL CREATE TABLE and ALTER TABLE statements:

Trigger	Description
ONUPDATE	The specified procedure is called prior to an update operation on the table. If the procedure returns .F., then the UPDATE is canceled. e.g. SQL> ALTER TABLE customer modify ONUPDATE "p_update";
ONDELETE	The specified procedure is called prior to a delete operation on the table. If the procedure returns .F., then the DELETE is canceled. e.g. SQL> ALTER TABLE customer modify ONDELETE "p_delete";
ONINSERT	The specified procedure is called prior to an insert operation on the table. If the procedure returns .F., then the INSERT is canceled. e.g. SQL> ALTER TABLE customer modify ONINSERT "p_insert";
ONOPEN	The specified procedure is called after an open operation on the table. e.g. SQL> ALTER TABLE customer modify ONOPEN "p_open";
ONCLOSE	The specified procedure is called prior to a close operation on the table. e.g. SQL> ALTER TABLE customer modify ONCLOSE "p_close";
ONROLLBACK	The specified procedure is called when a user presses the [ABANDON] key in a forms based operation. e.g. SQL> ALTER TABLE customer modify ONROLLBACK "p_rollback";

SECURITY

As mentioned above, all Recital files are subject to Operating System read and write permissions. These permissions can be further refined, while still using the Operating System user and group IDs, in the Security and Protection sections of the Dictionary. The Security section handles table based operations and the Protection section focuses on individual fields.

Security and Protection rules can be defined in the CREATE/MODIFY STRUCTURE worksurface of Recital Terminal Developer, via the SQL GRANT and REVOKE statements or in the Recital Enterprise Studio Database Administrator.

Click image to display full size

Fig 5: MODIFY STRUCTURE Worksurface: Security.

The Security section has table operations for which Access Control Strings can be specified. An Access Control String (ACS) is a range of valid user identification codes, and is used to restrict table operations to certain individuals or groups. Each user on the system is allocated a group number and a user number. The user identification code is the combination of group and user numbers. When constructing an Access Control String of linked user identification codes, wild card characters may be used.

Example ACS	Description
[1,2]	In group 1, user 2
[100,*]	In group 100, all users
[2-7,*]	In groups 2-7, all users
[*,100-200]	In all groups, users 100-200
[1,*]&[2-7,1-7]	In group 1, all users, in groups 2-7, users 1-7

Please note that the maximum ACS length is 254 characters. OpenVMS group and user numbers are stored and specified in octal. On other Operating Systems, group and user numbers are stored and specified in decimal.

Access Control Strings may be associated with the following operations:

Operation	Description
READONLY	Users specified in the ACS have read-only access to the table. All other users have update access.
UPDATE	Users specified in the ACS have update access to the table. All other users are restricted to read-only access.
APPEND	Users specified in the ACS can append records into the table. No other users can append.
DELETE	Users specified in the ACS can delete records from the table. No other users can delete.
COPY	Users specified in the ACS can copy records from the table. No other users can copy.
ADMIN	Users specified in the ACS can use the following commands: SET DICTIONARY TO MODIFY STRUCTURE PACK ZAP REINDEX All other users cannot, except the creator of the table, who is always granted ADMIN access.

The corresponding SQL privileges are:

Operation	Description
SELECT	Users specified in the ACS may name any column in a SELECT statement. All other users have update access.
UPDATE	Users specified in the ACS may name any column in an UPDATE statement. All other users are restricted to read-only access.
INSERT	Users specified in the ACS can INSERT rows into the table. No other users can INSERT.
DELETE	Users specified in the ACS can DELETE rows from the table. No other users can DELETE.
ALTER	Users specified in the ACS can use the ALTER TABLE statement on this table.
READONLY	Users specified in the ACS may read any column in a SELECT statement. All other users have update access.

// Grant insert privilege for the customer table
exec sql
  OPEN DATABASE southwind;
exec sql
  GRANT UPDATE (lastname, firstname)
  INSERT ON customers
  TO '[20,100]'; 
	
// Grant all privileges to all users
exec sql
  OPEN DATABASE southwind;
exec sql
  GRANT ALL 
  ON shippers TO PUBLIC;

PROTECTION

Click image to display full size

Fig 6: Database Administrator: Protection.

The format of the ACS is the same as in <SECURITY> above. The following protection can be defined:

Operation	Description
READONLY	Users specified in the ACS have read-only access to the field. All other users have update access.
UPDATE	Users specified in the ACS have update access to the field. All other users are restricted to read-only access.

Recital Terminal Developer also has 'HIDDEN' Protection:

Operation	Description
HIDDEN	Users specified in the ACS see the 'hiddenfield'character rather than the data in the field. All other users see the data.

Hidden fields can be accessed and viewed on a work surface, but the field contains the hiddenfield character, ‘?’. If the field is referenced in an expression, it will contain the following: blanks for character fields, ‘F’ for logical fields, 00/00/0000 for date fields and blank for memo fields.

The corresponding SQL privileges are:

Operation	Description
SELECT	Users specified in the ACS may name the column in a SELECT statement. All other users have update access.
UPDATE	Users specified in the ACS may name the column in an UPDATE statement. All other users are restricted to read-only access.
READONLY	Users specified in the ACS may read the column in a SELECT statement. All other users have update access.

// Grant update privilege for columns lastname and firstname from the customer table
exec sql
  OPEN DATABASE southwind;
exec sql
  GRANT UPDATE (lastname, firstname)
  customers TO '[20,100]';

Encryption

From Recital 8.5 onwards, Recital installations that have the additional DES3 license option have the ability to encrypt the data held in Recital database tables. Once a database table has been encrypted, the data cannot be accessed unless the correct three-part encryption key is specified, providing additional security for sensitive data.

ENCRYPT

The ENCRYPT Recital 4GL command is used to encrypt the data in the specified table or tables matching a skeleton. If the skeleton syntax is used, then all matching tables will be given the same encryption key. The encryption key is a three part comma-separated key and may optionally be enclosed in angled brackets. Each part of the key can be a maximum of 8 characters. The key is DES3 encrypted and stored in a .dkf file with the same basename as the table. After encryption, the three parts of the key must be specified correctly before the table can be accessed.

// Encrypt individual tables
encrypt customers key "key_1,key_2,key_3"
encrypt employees key "<key_1,key_2,key_3>"

// Encrypt all .dbf files in the directory
encrypt *.dbf key "key_1,key_2,key_3"

SET ENCRYPTION

If a database table is encrypted, the correct three-part encryption key must be specified before the table's data or structure can be accessed. The SET ENCRYPTION TO set command can be used to specify a default encryption key to be used whenever an encrypted table is accessed without the key being specified. The encryption key is a three part comma-separated key.

If the command to access the table includes the key, either by appending it to the table filename specification or using an explicit clause, this will take precedence over the key defined by SET ENCRYPTION TO.

Issuing SET ENCRYPTION TO without a key causes any previous setting to be cleared. The key must then be specified for each individual encrypted table.

The default key defined by SET ENCRYPTION is only active when SET ENCRYPTION is ON. SET ENCRYPTION OFF can be used to temporarily disable the default key. The SET ENCRYPTION ON | OFF setting does not change the default key itself. SET ENCRYPTION is ON by default.

// Encrypt individual tables
encrypt customers key "key_1,key_2,key_3"
encrypt shippers key "key_2,key_3,key_4"
// Specify a default encryption key
set encryption to "key_1,key_2,key_3"
// Open customers table using the default encryption key
use customers
// Specify shippers table's encryption key
use shippers<key_2,key_3,key_4>
// Disable the default encryption key
set encryption to
// Specify the individual encryption keys
use customers encryption "key_1,key_2,key_3"
use shippers<key_2,key_3,key_4>

DECRYPT

The DECRYPT command is used to decrypt the data in the specified table or tables matching a skeleton. The specified key must contain the three part comma-separated key used to previously encrypt the table and may optionally be enclosed in angled brackets. The skeleton syntax can only be used if all tables matching the skeletonhave the same key.

The DECRYPT command decrypts the data and removes the table’s .dkf file. After decryption, the key need no longer be specified to gain access to the table.

// Decrypt individual tables
decrypt customers key "key_1,key_2,key_3"
decrypt employees key "<key_1,key_2,key_3>"

// Decrypt all .dbf files in the directory
decrypt *.dbf key "key_1,key_2,key_3"

All of the following commands are affected when a table is encrypted:

APPEND FROM
COPY FILE
COPY STRUCTURE
COPY TO
DIR
USE
SQL INSERT
SQL SELECT
SQL UPDATE

APPEND FROM

Used to append records to the active table from another table.

// The key must be specified for an encrypted source table
use mycustomers
append from customers encryption "key_1,key_2,key_3";
for country = "UK"

COPY FILE

Used to copy a file.

// The key file must also be copied for an encrypted source table
// as the target table will be encrypted
encrypt customers key "key_1,key_2,key_3"
copy file customers.dbf to newcustomers.dbf
copy file customers.dkf to newcustomers.dkf
use newcustomers encryption "key_1,key_2,key_3"

COPY STRUCTURE

Used to copy a table's structure to a new table.

// The key file is automatically copied for an encrypted source table
// and the target table encrypted
encrypt customers key "key_1,key_2,key_3"
use customers encryption "key_1,key_2,key_3"
copy structure to blankcust
use blankcust encryption "key_1,key_2,key_3"

COPY TO

Used to copy a table.

// By default, the key file is automatically copied for an encrypted
// source table and the target table encrypted with the same key
encrypt customers key "key_1,key_2,key_3"
use customers encryption "key_1,key_2,key_3"
copy to newcustomers
use newcustomers encryption "key_1,key_2,key_3"

// You can also create a copy with a different key
encrypt customers key "key_1,key_2,key_3"
use customers encryption "key_1,key_2,key_3"
copy to newcustomers encrypt "newkey_1,newkey_2,newkey_3"
use newcustomers encryption "newkey_1,newkey_2,newkey_3"

// Or create a decrypted copy
encrypt customers key "key_1,key_2,key_3"
use customers encryption "key_1,key_2,key_3"
copy to newcustomers decrypt
use newcustomers

// You can also create an encrypted copy of a non-encrypted source table
use orders
copy to encorders encrypt "newkey_1,newkey_2,newkey_3"
use encorders encryption "newkey_1,newkey_2,newkey_3"

DIR

Used to display a directory listing of tables.

// Encrypted tables are flagged as such with (DES3)
> open database southwind
> dir

Current database: southwind
Tables				# Records		Last Update	Size		Dictionary	Triggers	Security
categories.dbf			8			01/10/06		24576	None		None		None
cisamdemo.dbf       ---> CISAM/Bridge        [cisamdemo]
customers.dbf (DES3)		91			05/12/04		49600	None		None		None
employees.dbf			9			05/12/04		25520	None		None		None
example.dbf   (DES3)		100			12/24/05		38080	Yes		Yes		None
order_details.dbf			2155			05/12/04		296320	None		None		None
orders.dbf				829			05/12/04		232704	None		None		None
products.dbf			77			05/12/04		37112	None		None		None
productsbyname.dbf		77			05/12/04		29104	None		None		None
shippers.dbf  (DES3)		3			05/12/04		20864	None		None		None
suppliers.dbf			29			12/08/05		29992	Yes		None		None

   0.765 MB in 11 files.
   1.093 GB remaining on drive.

USE

Used to open a table.

// The three part key must be specified to open an
// encrypted table.  All of the following are valid.
// 1. Specifying a default encryption key before opening the table
set encryption to "key_1,key_2,key_3"
use customers
// 2. Appending the key to the filename
use customers<key_1,key_2,key_3>
// 3. Using the ENCRYPTION clause, optionally specifying angled brackets
use customers encryption "key_1,key_2,key_3"
use customers encryption "<key_1,key_2,key_3>"

SQL INSERT

Used to add a row to a table via SQL.

// The three part key can be specified using a
// default encryption key before opening the table
exec sql
  OPEN DATABASE southwind;
exec sql
  SET ENCRYPTION TO "key_1,key_2,key_3";
exec sql
  INSERT INTO customers
  (customerid, companyname)
  VALUES
  ('RECIT','Recital Corporation');
// Or by appending the key to the filename
exec sql
  OPEN DATABASE southwind;
exec sql
  INSERT INTO customers<key_1,key_2,key_3>
  (customerid, companyname)
  VALUES
  ('RECIT','Recital Corporation');

SQL SELECT

Used to return data from a table via SQL.

// The three part key can be specified using a
// default encryption key before opening the table
exec sql
  OPEN DATABASE southwind;
exec sql
  SET ENCRYPTION TO "key_1,key_2,key_3";
exec sql
  SELECT * FROM customers;
// Or by appending the key to the filename
exec sql
  OPEN DATABASE southwind;
exec sql
  SELECT * FROM customers<key_1,key_2,key_3>;

SQL UPDATE

Used to update data in a table via SQL.

// The three part key can be specified using a
// default encryption key before opening the table
exec sql
  OPEN DATABASE southwind;
exec sql
  SET ENCRYPTION TO "key_1,key_2,key_3";
exec sql
  UPDATE customers
  SET companyname='Recital Corporation Inc.'
  WHERE customerid='RECIT';
// Or by appending the key to the filename
exec sql
  OPEN DATABASE southwind;
exec sql
  UPDATE customers<key_1,key_2,key_3>
  SET companyname='Recital Corporation Inc.'
  WHERE customerid='RECIT';

Summary

Recital offers a range of ways to keep your data secure. These start with the Operating System read/write permissions, which can be further refined to the level of table I/O operations and then field access in the Dictionary based Security and Protection rules. The Dictionary also provides the means to protect the integrity of the data via data validation and to assist in correct data entry through the use of choicelists, help messages and picture clauses etc. A further role of the Dictionary is in the provision of Table Triggers, which can be used to enable a programmatic response to table operations to add in additional checks or audit trails. For the most sensitive data, DES3 encryption is the ultimate protection: encrypting the physical data on the disk and only permitting table access on the production of the three part encryption key.

Published in Blogs

Can I use the Recital scripting language with MySQL, Oracle, DB2 or Postgres?

Yes. This article explains how.

Published in Blogs

Typography

Warnings
Headers
Icon set 1
Icon set 2
Icon set 3
Tooltips
Highlights
Code
Unordered lists
Ordered lists
Abbrs and acronyms
Definition lists
Legends
Dropcaps
Floated blocks
Other span blocks
Blockquotes
Tables

Warnings

This is a sample info message. Use Your info message goes here!.

This is a sample tips message. Use Your tips goes here!.

This is a sample warning message. Use Your warning message goes here!.