isCOBOL Evolve : Language Reference : Embedded SQL Statements : CONNECT
CONNECT
The CONNECT statement allows you to connect to a database.
Format 1
EXEC SQL
 
  CONNECT [ TO [ { Database-Name } ] [ AS Connection-Name ] ]
                 { DEFAULT       }
 
          [ USER User-Name [ USING Password ] ]
 
END-EXEC
Format 2
EXEC SQL
 
  CONNECT  [ {  User-Name IDENTIFIED BY Password }[ AT Database ] USING Database-Name ]
            { Usr-Pwd                          }
END-EXEC
Format 3
EXEC SQL
 
  CONNECT  USING Connection-String
 
END-EXEC
Syntax rules
1. Database-Name, User-Name, Usr-Pwd, Password , DBString, Connection-Name and Connection-String are Nonnumeric Literals, as defined in the Definitions section of the Preface of this document or Host Variables.
General rules
1. The connect statement must precede all statements that access the database.
2. In Format 1, when Database-Name is omitted or DEFAULT is specified, no database name is passed to the jdbc driver. If USER and USING are omitted too, then no parameter is passed to the jdbc driver, assuming that all the necessary information is provided by the iscobol.jdbc.url configuration property.
3. In Format 2, when the USING phrase is omitted no database name is passed to the jdbc driver. If user and password credentials are omitted too, then no parameter is passed to the jdbc driver, assuming that all the necessary information is provided by the iscobol.jdbc.url configuration property.
4. Connection-String should contain all the necessary information for the connection to the database, e.g. driver class and connection URL. The following formats are supported:
o DRIVER=<driver-class>;URL=<connection-url>
o DRIVER=<driver-class>
o URL=<connection-url>
o <connection-url>
 
If either the driver class or the connection URL is not provided, the runtime retrieves the information from the iscobol.jdbc.driver and the iscobol.jdbc.url configuration properties.
5. When the AS phrase is omitted, the connection name is the same as the database name.
6. Once connected you can retrieve the connection handle by invoking the getCurrConnection() method of the com.iscobol.rts.EsqlRuntime object. This method returns a java.sql.Connection that can be passed to other java programs. See EsqlRuntime (com.iscobol.rts.EsqlRuntime) for more information.
7. Usr-Pwd contains both UserName and Password separated by "/". Example: UsrPWD = "scott/tiger".
8. Database must be previously defined using a Format 4 DECLARE statement.
9. If the iscobol.jdbc.datasource configuration property specifies a valid class, then the connect() method of that class is invoked to gain connection. If the property is not set, then the runtime invokes the Java SQL DriverManager to gain connection. The following snippet shows a prototype of a valid class
import java.sql.*;
import javax.sql.*;
public class myDataSource implements com.iscobol.rts.MyDataSource {
   public Connection connect (String dsn, String usr, String pwd)
                                                throws SQLException {
      Connection conn = getMyConnection(usr, pwd);
      return conn;
   }
   private Connection getMyConnection(String usr, String pwd) {
      // do the necessary operation to get the connection
   }
}
Note - The parameters dsn, user and passwd are the ones used in the CONNECT statement. If the program performs just CONNECT because database name and login credentials were put in the JDBC URL, then the class does not receive any parameter.
 
To make isCOBOL use the above class for connection, set
iscobol.jdbc.datasource=myDataSource
10. Connection-Name can be referenced by the SET CONNECTION statement.
Examples
Format 1 - Connect to the ctree database
move "ctreeSQL" to dbname
move "admin"    to userid
move "ADMIN"    to passwd
exec sql 
   connect to :dbname 
         user :userid  
        using :passwd
end-exec