Java JDBC API

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Java JDBC API
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A Java API

• To Access almost any kind of tabular data
• Trademarked (not an acronym)
• A set of classes and interfaces written in Java
• Supports all dialects of SQL
• Goes beyond SQL makes it possible to interact
  with other kinds of data sources such as files
  containing tabular data

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Features

• Can access almost any data source
• Can run on any platform with a Java Virtual
  Machine

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Examples

• Possible to publish a web page containing an
  applet that uses information obtained from a
  remote data source
• A company can connect all employees (using a
  collection of Windows, Mac, UNIX machines) to
  internal databases through an intranet
• One can write a single program to send SQL
  statements to, e.g., an Oracle DB, a Sybase DB,
  and IBM DB2 DB.

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What Does the Java API Do?

• Establish a connection with a data source
• Send queries and update statements to the data
  source
• Process the results

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Code Snippet

• Connection con DriverManager.getConnection(
• jdbcoraclethin_at_c
  s.gonzaga.edu1521basicdb,
• myLogin,
  myPasswd)
• Statement stmt con.createStatement()
• ResultSet rs stmt.executeQuery(select lname
  from employee)
• while (rs.next())
• System.out.println(rs.getString(1))
• stmt.close()

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JDBC is similar to ODBC

• An API for accessing data stores
• But
• It is partly written in C and so loses Javas
  portability, security
• JDBC is simpler than ODBC
• JDBC is written in Java for Java applications

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JDBC Application (2-Tier Model)
Java Application
JDBC
DBMS
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JDBC Applet (3-Tier Model)
Browser (Java Applet)
Java Program
JDBC
DBMS
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Java Strengths

• Java is portable
• Java is object-oriented
• Large library of classes and interfaces
• Examples
• Applets
• Graphics
• Sql
• Security

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Continued

• Java makes it easier to write correct code
• Automatic garbage collection
• No pointers
• Strong typing
• Exception handling
• Simplicity (no templates or multiple inheritance)

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Continued

• Security Features
• Memory layout is determined at run-time (unlike
  c/c where compiler makes layout decisions)
• Therefore, a programmer cant look at a class
  def. and figure out how it might be laid out
• JVM checks incoming code for forged pointers,
  access restrictions
• Classes from across the network cant be
  substituted for built-in classes
• Built-in classes cant accidentally reference
  classes from across the network.