// declare some simple procedures
proc display(cArg)
echo "display=" + cArg
endproc
proc show(cArg)
echo "show=" + cArg
endproc
// create an object based on an anonymous class
myobj = new object()
// add some properties
myobj["name"] = "barry"
myobj["company"] = "recital"
// now declare an anonymous method
myobj["mymethod"] = display
// call the method
myobj.mymethod("hello world") // displays "display=hello world"
// redeclare the method
myobj["mymethod"] = show
// call the method
myobj.mymethod("hello world") // displays "show=hello world"
Where this becomes particularly useful is when you have a procedure that calls anonymous methods in order to process data. This technique can be used to call anonymous procedures in your code.
proc processdata(oArg)
oArg.mymethod(oArg.name)
endproc
proc show(cArg)
echo "show=" + cArg
endproc
myobj = new object()
myobj["name"] = "barry"
myobj["mymethod"] = show
processdata(myobj) // displays "show=barry" 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 tables 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 columns 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. |
|
ONDELETE |
The specified procedure is called prior to a delete operation
on the table. If the procedure returns .F., then the DELETE
is canceled. |
|
ONINSERT |
The specified procedure is called prior to an insert operation
on the table. If the procedure returns .F., then the INSERT
is canceled. |
|
ONOPEN |
The specified procedure is called after an open operation
on the table. |
|
ONCLOSE |
The specified procedure is called prior to a close operation
on the table. |
|
ONROLLBACK |
The specified procedure is called when a user presses the
[ABANDON] key in a forms based operation. |
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: |
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
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 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.
When you start the loadbalancer.org appliance you will see the following:
Default login:
Username: root
Password: loadbalancer
Access to webclient from an external client is:
http://192.168.1.129:9080
http://192.168.1.129:9443
You can access the web administrator using the IP and ports described onscreen.
For the sri lanka porject we are looking for performance and the network diagram indicates we are happy to have the cluster on the same subnet as the rest of the network.
Direct routing is the fasted performance possible, it has the advantage over NAT that the Loadbalancer does not become a bottleneck for incoming and outgoing packets. With DR the loadbalancer simply examines incoming packets and the servers to route the packets directly back to the requesting user.
The web interfaceis the only way to fully configure the loadbalancer vm. The console tool lbwizard will get it initiallised and any further configurations can then be done via the webinterface.
Using lbwizard for the Sri lanka configuration follow these steps.
On the first Loadbalancer:
//Start
Is this unit part for a HA Pair?
YES
Have you already setup the Slave?
NO
Is this a one-armed configuration?
YES
Enter the IP Address for the interface eth0?
Enter IP address you wish to be assigned to the SLAVE loadbalancer.
Enter the netmask for interface eth0?
Enter netmask for the subnet.
Enter the Floating IP adrress?
Enter the IP address that will be IP assosiacted the the HA-pair of loadbalancers.
//Finish
On the 2nd loadbalancer VM, run the lbwizard.
//Start
Is this unit part of an HA-Pair?
YES
Have you already set up the Slave?
YES
What is the slave units UP address?
Enter the IP which you entered when configuring the other loadbalancer VM.
Is this a one-armed configuration?
YES
Enter the IP Address for the interface eth0?
Enter the IP that will be assigned to the MASTER loadbalancer
Enter the netmask for interface eth0?
Enter the subnet netmask.
Enter the Floating IP address?
Enter the IP address that will be IP assosiacted the the HA-pair of loadbalancers.
Enter the address of the default gateway?
Enter the deafult gateway for the subnet.
Enter the IP of the nameserver?
Enter the dns server.
Enter the port for the first Virtual server?
Enter 22 for ssh
Enter the IP address of the first real server?
Enter the real IP of the first appserver
//Finish
Now this is complete we need to go to the web admin interface to configure the 2nd Real Server. As the lbwizard program will only allow you to configure 1 real server.
Now login to the web admin using the default password:
username: loadbalancer
password: loadbalancer
Note: Connect to the IP you have now set for your master loadbalancer
Goto the edit configuration tab
Now click add a real server:
Enter a label
IP address of the server plus the port of the service i.e. 192.168.1.125:22
Edit Configuration -> Virtual Servers
persistancte -> NO
Scheduler-> LC
LC - Least-Connection: assign more jobs to real servers with
fewer active jobs.
Service to check -> custom1
Check port -> 22
Forwarding Method -> DR
Feedback Method -> Agent
Arp Problem when using DR
Every real server must be configured to respond to the VIP address as well as the RIP
address.
You can use iptables (netfilter) on the real server to re-direct incoming packets destined for the virtual
server IP address.
This is a simple case of adding the following command to your start up script (rc.local):
//replace 10.0.0.21 with the Virtual Server IP
iptables -t nat -A PREROUTING -p tcp -d 10.0.0.21 -j REDIRECT
chkconfig iptables on
Recital is a proven and cost-effective database solution that will help reduce the cost of your database and application software infrastructure substantially. As an added benefit, Recital can run many legacy applications with little to no change as it understands FoxBASE, FoxPRO and Clipper languages as a subset of it's overall capability.
http://kbala.com/ie-9-supports-corner-radius/
Recital is a rich and versatile product with many ways to do the same thing. Developers usually write code in the way that they are accustomed to without paying much attention to how this will perform in a multi-user environment with large amounts of users and transactions. The best way to optimize Recital applications is to use the built-in tuning capabilities introduced in Recital 10.
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
|
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. Using Gateways, you can transparently access the following local or remote data sources:
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
ImportantWhen 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();
}
Key features of the Recital scripting language include:
What are the key feature of the Recital database?
- High performance database application scripting language
- Modern object-oriented language features
- Easy to learn, easy to use
- Fast, just-in-time compiled
- Develop desktop or web applications
- Cross-platform support
- Extensive built-in functions
- Superb built-in SQL command integration
- Navigational data access for the most demanding applications