200 likes | 356 Views
JDBC. Java API for Database Connectivity. Layout of this recitation. Introduction to JDBC API JDBC Architecture Understanding the design of JDBC API Classes and relations among them. What is an API?. a pplication p rogram i nterface
E N D
JDBC Java API for Database Connectivity
Layout of this recitation • Introduction to JDBC API • JDBC Architecture • Understanding the design of JDBC API • Classes and relations among them
What is an API? • application program interface • a set of routines, protocols, and tools for building software applications • provides all the building blocks
What you expect in DB API Java Application Java DB API • Open a Connection • Send a statement • Retrieve results • Close a connection DBMS Engine • Create a connection Session • Execute statement • Send results • Close the session
Big picture Java Application JDBC API JDBC Manager JDBC Driver API JDBC Drivers Grey Area Data Sources
JDBC driver type-1 • Uses the existing API • Not the fastest JDBC-ODBC Bridge Java ODBC Driver Native Driver Non Java Net Driver
JDBC driver type-2 • Uses vendor-provided local libraries • Most efficient JDBC Driver Java Native Driver Non Java Net Driver
JDBC driver type-3 & 4 • 100% java. JDBC – Net Driver Java JDBC Driver Implements a proprietary Protocol in java Java
Complete JDBC Architecture Java Application JDBC Interface JDBC Driver Manager JDBC Driver Interface JDBC Net Driver A JDBC–ODBC Bridge B JDBC Driver C JDBC Driver D ODBC Driver Native Driver C Native Driver B A B C D
On Different Platforms JDBC Driver Classes JDBC API PC DBMS MAC Unix
JDBC Interface classes • Java.sql package • DriverManager • Connection • Statement • CallableStatement • PreparedStatement • Resultset • ResultSetMetaData • DatabaseMetatData
JDBC Interfaces Driver Manager Connection Connection Connection Statement Prepared Statement ResultSet
Simple Example Import java.sql; class SimpleExample { public static void main(String args[]) { String url = “jdbc:odbc:mysource”; try { Class.forName(“sun.jdbc.odbc.JdbcOdbcDriver”); Connection myConnection = DriverManager.getConnection(url,”Bond”,”TopSecret”); myConnection.close(); } catch(java.lang.Exception) { ex.printStackTrace(); } } }
Sending SQL statements …… String query= “Select name,id,salary FROM employees ORDER By salary”; Connection myConnection = DriverManager.getConnection(…..); Statement myStatement = myConnection.createStatement(); ResultSet rs = myStatement.executeQuery(query); While(rs.next){ String empName = rs.getString(1); String empId = rs.getString(2); String empSalary = rs.getString(3); System.out.println(“Employee ” + empName + “ with id ” + empId + “ earns ” + empSalary); } myStatement.close(); myConnection.close(); …….
Statement’s Execute Methods • ResultSet executeQuery() • For SQL selects • int executeUpdate() • For Update,Delete,Insert and Create etc. • boolean execute() • For either type • Returns resultSetisAvailable
Statements • Statement • PreparedStatement • CallableStatement
Additional stuff • Datatypes: basic to CLOB, BLOB • Transaction Management • DDA with/without cursors • Batch updates • Metadata • DatabaseMetaData • ResultSetMetaData • ParameterMetaData
Advanced Techniques • Connection Pooling • Dynamic SQL with Prepared Statements • Auto-generated keys
References • www.google.com • http://java.sun.com/j2se/1.4/docs/api/ • JDBC 3.0: Java Database Connectivity. • Bernard Van Haecke