Do You Make These Mistakes?

The smallest meaningful grouping of code is known as a block. A block is a unit of code that provides execution and scoping boundaries for variable declarations and exception handling. PL/SQL allows you to create anonymous blocks (blocks of code that have no name) and named blocks, which may be packages, procedures, functions, triggers, or object types. A PL/SQL block has up to four different sections, only one of which is mandatory: Example:- --Header Section PROCEDURE myFirstProcedure(NAME IN Varchar2) IS --Declaration Section SALARY NUMBER; JOINING_DATE DATE; BEGIN --Execution Section INSERT INTO EMPLOYEE (emp_name, salary, joining_date) VALUES (name, salary, joining_date); EXCEPTION --Exception Section WHEN DUP_VAL_IN_INDEX THEN DBMS_OUTPUT.PUT_LINE ("Duplicate Value, Cannot Insert."); END; /

You want to save output from a SQL*Plus session to a file to get record of your actions, or because you are dynamically generating commands to execute later. This can be done in SQL*Plus with the help of SPOOL command: SQL> SPOOL report.txt SQL> @run_report.sql ...output scrolls past and gets written to the file report.txt... SQL> SPOOL OFF The first command, SPOOL report, tells SQL*Plus to save everything from that point forward into the file report.txt. The file extension of .lst is the default and can be overridden by supplying your own extension in the SPOOL command like specified above. SPOOL OFF tells SQL*Plus to stop saving the output and to close the file.

SQL*Plus can also create and manipulate its own in-memory variables, and it sets aside a few special variables that will affect its behavior. Actually, there are two separate types of variables in SQL*Plus: DEFINEs and bind variables. To assign a value to a DEFINE variable, you can use the DEFINE command: SQL> DEFINE X = "UMASARATH" To view the value of x, specify: SQL> DEFINE X DEFINE X               = "UMASARATH" (CHAR) SQL> You would refer to such a variable using an ampersand (&). SQL*Plus does a simple substitution before sending the statement to the Oracle database, so you will need single-quote marks around the variable when you want to use it as a literal string. SQL> select '&x' from dual; old   1: select '&x' from dual new   1: select 'UMASARATH' from dual 'UMASARAT --------- UMASARATH SQL>

The javax.servlet package contains a number of interfaces and classes that establish the framework in which servlets operate. The most significant of these is Servlet. All servlets must implement this interface or extend a class that implements the interface Interface Description Servlet Declares life cycle methods for a servlet. ServletConfig Allows servlets to get initialization parameters ServletContext Enables servlets to log events and access information about their environment. ServletRequest Used to read data from a client request. ServletResponse Used to write data to a client response. The following table summarizes the core classes that are provided in the javax.servlet package: Class Description GenericServlet Implements the Servlet and ServletConfig interfaces. ServletInputStream Provides an input stream for reading requests from a client. ...

Two packages contain the classes and interfaces that are required to build servlets. javax.servlet javax.servlet.http These packages are the standard extensions provided by Tomcat. Hence, these are not included in Java 6. Please follow the links for more information.

There might be a chance in your company is that a firewall is set up a and an HTTP proxy server to stop user to connect to internet directly. If you are behind a proxy, Maven will fail to download any dependencies. To make it work, you have to declare the proxy server setting in Maven configuration file settings.xml .  It can be found in conf directory, i.e.,  {M2_HOME}/conf/settings.xml. {M2_HOME}/conf/settings.xml <! -- proxies | This is a list of proxies which can be used on this machine to connect to the network. | Unless otherwise specified ( by system property or command-line switch ) , the first proxy | specification in this list marked as active will be used. | -- > < proxies > <! -- proxy | Specification for one proxy, to be used in connecting to the network. | < proxy > < id > optional </ id > < active > true </ active > < protocol > http </...

Apache Maven is an innovative software project management tool, provides new concept of a project object model ( POM ) file to manage project’s build, dependency and documentation. The most powerful feature is able to download the project dependency libraries automatically. We will show you how to install Apache Maven 3 on Ubuntu 12. Searching for Maven Package In a terminal, run apt-cache search maven  to get all the available Maven package. The maven  package always comes with latest Apache Maven. $ apt-cache search maven .... libxmlbeans-maven-plugin-java-doc - Documentation for Maven XMLBeans Plugin maven - Java software project management and comprehension tool maven-debian-helper - Helper tools for building Debian packages with Maven maven2 - Java software project management and comprehension tool Installing Maven Package Run the below command  to install the latest Apache Maven. $ sudo apt-get install maven Verifying Maven Installation Run the be...