Transcript JDBC

Oracle Programming
Instructor: Xintao Wu
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architecture
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JDBC (Java Database Connectivity )
JDBC enables programmers to use SQL
queries from within java programs to access
databases.
 JDBC provides transparent access to
relational databases from different vendors.
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JDBC
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JDBC steps
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Create the database in your dbms
Register the database as a data source
Import java.sql.* at the beginning of your java file.
Connect to a JDBC source
– Connection con =
DriverManager.getConnection(“jdbc:oracle:thin:@cciora02.uncc.edu:1521:class”,”user”,”passwd”)
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Create an SQL statement
– Statement stmt = con.createStatement();
– stmt.executeUpdate("INSERT INTO sailor
VALUES(22,'dustin',7,45.0)");
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JDBC Step
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Execute the statement
– ResultSet rs = stmt.executeQuery(“Select * from …”)
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Parse the result
– rs.next(), rs.getFloat
– ResultSetMetaData contains the information about column
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Close the statement and connection
– stmt.close()
– con.close
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Useful resources
JDBC tutorial
http://java.sun.com/docs/books/tutorial/jd
bc/index.html
 UNCC COIT
https://cci-wiki01.uncc.edu/servlets
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Example
http://www.sis.uncc.edu/~xwu/WEBINF/classes/SampleJDBC.java
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Java Servlets
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Web servers understand requests for pages in http
and return their response in HTML format
Static html vs. dynamic html
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The webpage is based on data submitted by the user
The data changes frequently (a weather-report)
Web pages uses information from a database(stock)
Maintain separate data about each client for personalization
purposes(cookies).
Java servlets are programs that extend the
functionality of a web server and useful for building
dynamic web pages on the fly.
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Java Servlet Advantage
Works as a lightweight thread directly with
the JVM rather than create a new process
 Load once to memory and used by all threads
 Share data among each other
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How to run servlets
Your machine, Java servlet development
kit(JSDK)
 COIT
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– consult the webpage
https://cci-wiki01.uncc.edu/servlets
– Consult TA
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Examples
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HelloWorld
– http://coit-servlet02.uncc.edu:8080/xwu/HelloWorld
– http://www.sis.uncc.edu/~xwu/WEBINF/classes/HelloWorld.java
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More examples
– DBServlet
– http://coit-servlet02.uncc.edu:8080/xwu/DBServlet.html
– http://www.sis.uncc.edu/~xwu/WEBINF/classes/DBServlet.java
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JDBC and Servlet
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Summary:
1. Download PUTTY and WinSCP
2. Download HelloWorld, SampleJDBC and DBServlet source code
3. Modify them and upload to your own space
4. Compile and run it
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Some links
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https://cci-wiki01.uncc.edu/servlets
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http://www.sis.uncc.edu/~xwu/5160/JDBC
-Servlet.doc
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Summary
3-tire architecture
 APIs such as JDBC and ODBC introduce a layer
of abstraction between application and DBMS
 Choose your language from JSP, Servlet, ASP,
VC++, VB.
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