Ever since we created our first stored packaged function, we have had to suffer a continual trade-off between the encapsulation of business rules and optimal performance. We have usually paid a performance penalty for good programming practices in one or more of the following ways: The last issue in the list has, however, been addressed for many releases of Oracle and we will see how in this article.
The basic steps in creating a JDBC application involve importing JDBC packages, loading and registering the JDBC driver, opening a connection to the database, creating a statement object to perform a query, executing the statement object, returning a query resultset, processing the resultset, closing the resultset and statement objects, and finally closing the connection.
This chapter explains the use of Java Database Connectivity for database access in Java. The various methods of using JDBC starting from the querying and returning of resultsets to executing DML from the Oracle 8i database are described in detail. A case study is presented to illustrate the concepts.
It also highlights the JDBC 2.
The details of the case study used to illustrate the various JDBC concepts throughout are presented. About JDBC JDBC provides a standard interface for accessing a relational database from a Java application regardless of where the application is running and where the database is. In other words it is a way to execute SQL statements and also call stored database procedures.
One important feature of JDBC is location independence. Java programs with database access can be written and deployed as an application or as a Web-based applet. The ease of development, robustness, and security of Java programs makes it a good choice for writing database applications in Java.
There are four types of drivers defined by JDBC as follows: It provides no host redirection capability. It also provides no host redirection. How the net server component accesses the database is transparent to the client. The client driver communicates with the net server using a database-independent protocol and the net server translates this protocol into database calls.
This type of driver can access any database. Again this is all transparent to the client. Load a JDBC driver. Optionally interrogate the database for capability subset. Optionally retrieve schema metadata information. Construct a SQL or callable statement object and send queries or database tasks.
Execute the database tasks or process resultsets. Close the statement object and resultset. These client-side and server-side drivers provide the same functionality and have the same syntax and APIs and they share the same Oracle extensions.Dynamic SQL is a programming methodology for generating and running SQL statements at run time..
It is useful when writing general-purpose and flexible programs like ad hoc query systems, when writing programs that must run database definition language (DDL) statements, or when you do not know at compile time the full text of a SQL statement .
PL/SQL - PL/SQL interview questions and answers by expert members with experience in PL/SQL subject.
Discuss each question in detail for better understanding and in-depth knowledge of PL/SQL. A PL/SQL subprogram is a named PL/SQL block that can be invoked repeatedly.
If the subprogram has parameters, their values can differ for each invocation.
A subprogram is either a procedure or a function. Typically, you use a procedure to perform an action and a function to compute and return a value. Compiling PL/SQL in Oracle 10g and beyond Mike Ault. As we noted, starting in Oracle 10g, PL/SQL can be compiled to native code.
The compiling, along with overall improvements in PL/SQL compilation can mean speeding up PL/SQL execution by up to 60%. Beginning PL/SQL: From Novice to Professional (Expert's Voice in Oracle) [Donald Bales] on srmvision.com *FREE* shipping on qualifying offers.
Beginning PL/SQL is a fast-paced and blissfully short introduction to Oracle's PL/SQL language. PL/SQL is the built-in language that every Oracle developer and database administrator simply must know.
Learning to design, build and manage database applications in Oracle 12c; Writing PL/SQL codes for developing stored procedures, triggers and packages.