1.  1992-2007 Pearson Education, Inc. All rights reserved. 1 25 Accessing Databases with JDBC

2.  1992-2007 Pearson Education, Inc. All rights reserved. 2 25.1Introduction 25.2Relational Databases 25.3Relational Database Overview: The books Database 25.4SQL 25.4.1 Basic SELECT Query 25.4.2 WHERE Claus 25.4.3 ORDER BY Claus 25.4.4Merging Data from Multiple Tables: INNER JOIN 25.4.5 INSERT Statement 25.4.6 UPDATE Statement 25.4.7 DELETE Statement 25.5Instructions for installing MySQL and MySQL Connector/J

3.  1992-2007 Pearson Education, Inc. All rights reserved. 3 25.6Instructions for Setting Up a MySQL User Account 25.7 Creating Database book in MySQL 25.8 Manipulating Databases with JDBC 25.8.1 Connecting to and Querying a Database 25.8.2 Querying the books Database 25.9 RowSet Interface 25.10 Java DB/Apache Derby 25.11 PreparedStatement s 25.12 Stored Procedures 25.13 Transaction Processing 25.14 Wrap-Up 25.15 Web Resources and Recommended Readings

4.  1992-2007 Pearson Education, Inc. All rights reserved. 4 25.1 Introduction  Database – Collection of data  DBMS – Database management system – Storing and organizing data  SQL – Relational database – Structured Query Language

5.  1992-2007 Pearson Education, Inc. All rights reserved. 5 25.1 Introduction (Cont.)  RDBMS – Relational database management system – MySQL - Open source - Available for both Windows and Linux - dev.mysql.com/downloads/mysql/4.0.hml  JDBC – Java Database Connectivity – JDBC driver - Enable Java applications to connect to database - Enable programmers to manipulate databases using JDBC

6.  1992-2007 Pearson Education, Inc. All rights reserved. 6 Software Engineering Observation 25.1 Using the JDBC API enables developers to change the underlying DBMS without modifying the Java code that accesses the database.

7.  2005 Pearson Education, Inc. All rights reserved. 7 25.2 Relational Databases Relational database – Table Rows, columns – Primary key Unique data SQL queries – Specify which data to select from a table

8.  1992-2007 Pearson Education, Inc. All rights reserved. 8 Fig. 25.1 | Employee table sample data.

9.  1992-2007 Pearson Education, Inc. All rights reserved. 9 Fig. 25.2 | Result of selecting distinct Department and Location data from table Employee.

10.  2005 Pearson Education, Inc. All rights reserved. 10 25.3 Relational Database Overview: The books Database Sample books database – Four tables authors – authorID, firstName, lastName titles – isbn, title, editionNumber, copyright, publisherID, imageFile, price authorISBN – authorID, isbn

11.  1992-2007 Pearson Education, Inc. All rights reserved. 11 Fig. 25.3 | authors table from the books database.

12.  1992-2007 Pearson Education, Inc. All rights reserved. 12 Fig. 25.4 | Sample data from the authors table.

13.  2005 Pearson Education, Inc. All rights reserved. 13 25.3 Relational Database Overview: The books Database (Cont.) Foreign key – A column matches the primary key column in another table – Helps maintain the Rule of Referential Integrity Every foreign key value must appear as another table’s primary key value

14.  1992-2007 Pearson Education, Inc. All rights reserved. 14 Fig. 25.5 | authorISBN table from the books database.

15.  1992-2007 Pearson Education, Inc. All rights reserved. 15 Fig. 25.6 | Sample data from the authorISBN table of books.

16.  1992-2007 Pearson Education, Inc. All rights reserved. 16 Fig. 25.7 | titles table from the books database.

17.  1992-2007 Pearson Education, Inc. All rights reserved. 17 Fig. 25.8 | Sample data from the titles table of the books database.

18.  2005 Pearson Education, Inc. All rights reserved. 18 25.3 Relational Database Overview: The books Database (Cont.) Entity-relationship (ER) diagram – Tables in the database – Relationships among tables Rule of Entity Integrity – Primary key uniquely identifies each row – Every row must have a value for every column of the primary key – Value of the primary key must be unique in the table

19.  1992-2007 Pearson Education, Inc. All rights reserved. 19 Fig. 25.9 | Table relationships in the books database.

20.  1992-2007 Pearson Education, Inc. All rights reserved. 20 Common Programming Error 25.1 Not providing a value for every column in a primary key breaks the Rule of Entity Integrity and causes the DBMS to report an error.

21.  1992-2007 Pearson Education, Inc. All rights reserved. 21 Common Programming Error 25.2 Providing the same value for the primary key in multiple rows causes the DBMS to report an error.

22.  1992-2007 Pearson Education, Inc. All rights reserved. 22 Common Programming Error 25.3 Providing a foreign-key value that does not appear as a primary-key value in another table breaks the Rule of Referential Integrity and causes the DBMS to report an error.

23.  2005 Pearson Education, Inc. All rights reserved. 23 25.4 SQL SQL keywords – SQL queries and statements

24.  1992-2007 Pearson Education, Inc. All rights reserved. 24 Fig. 25.10 | SQL query keywords.

25.  2005 Pearson Education, Inc. All rights reserved. 25 25.4.1 Basic SELECT Query Simplest format of a SELECT query – SELECT * FROM tableName SELECT * FROM authors Select specific fields from a table – SELECT authorID, lastName FROM authors

26.  1992-2007 Pearson Education, Inc. All rights reserved. 26 Fig. 25.11 | Sample authorID and lastName data from the authors table.

27.  1992-2007 Pearson Education, Inc. All rights reserved. 27 Software Engineering Observation 25.2 For most queries, the asterisk ( * ) should not be used to specify column names. In general, you process results by knowing in advance the order of the columns in the result—for example, selecting authorID and lastName from table authors ensures that the columns will appear in the result with authorID as the first column and lastName as the second column. Programs typically process result columns by specifying the column number in the result (starting from number 1 for the first column). Selecting columns by name also avoids returning unneeded columns and protects against changes in the actual order of the columns in the table(s).

28.  1992-2007 Pearson Education, Inc. All rights reserved. 28 Common Programming Error 25.4 If you assume that the columns are always returned in the same order from a query that uses the asterisk ( * ), the program may process the results incorrectly. If the column order in the table(s) changes or if additional columns are added at a later time, the order of the columns in the result would change accordingly.

29.  2005 Pearson Education, Inc. All rights reserved. 29 25.4.2 WHERE Clause specify the selection criteria – SELECT columnName1, columnName2, … FROM tableName WHERE criteria SELECT title, editionNumber, copyright FROM titles WHERE copyright > 2002

30.  1992-2007 Pearson Education, Inc. All rights reserved. 30 Portability Tip 25.1 See the documentation for your database system to determine whether SQL is case sensitive on your system and to determine the syntax for SQL keywords (i.e., should they be all uppercase letters, all lowercase letters or some combination of the two?).

31.  1992-2007 Pearson Education, Inc. All rights reserved. 31 Fig. 25.12 | Sampling of titles with copyrights after 2005 from table titles.

32.  2005 Pearson Education, Inc. All rights reserved. 32 25.4.2 WHERE Clause (Cont.) WHERE clause condition operators –, =, =, <> – LIKE wildcard characters % and _ SELECT authorID, firstName, lastName FROM authors WHERE lastName LIKE ‘D%’

33.  1992-2007 Pearson Education, Inc. All rights reserved. 33 Fig. 25.13 | Authors whose last name starts with D from the authors table.

34.  1992-2007 Pearson Education, Inc. All rights reserved. 34 Portability Tip 25.2 Read your database system’s documentation carefully to determine whether your system supports the LIKE operator. The SQL we discuss is supported by most RDBMSs, but it is always a good idea to check the features of SQL that are supported by your RDBMS.

35.  2005 Pearson Education, Inc. All rights reserved. 35 25.4.2 WHERE Clause (Cont.) SELECT authorID, firstName, lastName FROM authors WHERE lastName LIKE ‘_i%’

36.  1992-2007 Pearson Education, Inc. All rights reserved. 36 Fig. 25.14 | The only author from the authors table whose last name contains o as the second letter.

37.  2005 Pearson Education, Inc. All rights reserved. 37 25.4.3 ORDER BY Clause Optional ORDER BY clause – SELECT columnName1, columnName2, … FROM tableName ORDER BY column ASC SELECT authorID, firstName, lastName FROM authors ORDER BY lastName ASC – SELECT columnName1, columnName2, … FROM tableName ORDER BY column DESC SELECT authorID, firstName, lastName FROM authors ORDER BY lastName DESC

38.  1992-2007 Pearson Education, Inc. All rights reserved. 38 Fig. 25.15 | Sample data from table authors in ascending order by lastName.

39.  1992-2007 Pearson Education, Inc. All rights reserved. 39 Fig. 25.16 | Sample data from table authors in descending order by lastName.

40.  2005 Pearson Education, Inc. All rights reserved. 40 25.4.3 ORDER BY Clause (Cont.) ORDER BY multiple fields – ORDER BY column1 sortingOrder, column2 sortingOrder, … SELECT authorID, firstName, lastName FROM authors ORDER BY lastName, firstName

41.  1992-2007 Pearson Education, Inc. All rights reserved. 41 Fig. 25.17 | Sample data from authors in ascending order by lastName and firstName.

42.  2005 Pearson Education, Inc. All rights reserved. 42 25.4.3 ORDER BY Clause (Cont.) Combine the WHERE and ORDER BY clauses SELECT isbn, title, editionNumber, copyright, price FROM titles WHERE title LIKE ‘%How to Program’ ORDER BY title ASC

43.  1992-2007 Pearson Education, Inc. All rights reserved. 43 Fig. 25.18 | Sampling of books from table titles whose titles end with How to Program in ascending order by title.

44.  2005 Pearson Education, Inc. All rights reserved. 44 25.4.4 Merging Data from Multiple Tables: INNER JOIN Split related data into separate tables Join the tables – Merge data from multiple tables into a single view – INNER JOIN SELECT columnName1, columnName2, … FROM table1 INNER JOIN table2 ON table1.columnName = table2.column2Name SELECT firstName, lastName, isbn FROM authors, authorISBN INNER JOIN authorISBN ON authors.authorID = authorISBN.authorID ORDER BY lastName, firstName

45.  1992-2007 Pearson Education, Inc. All rights reserved. 45 Fig. 25.19 | Sampling of authors and ISBNs for the books they have written in ascending order by lastName and firstName.

46.  1992-2007 Pearson Education, Inc. All rights reserved. 46 Software Engineering Observation 25.3 If a SQL statement includes columns with the same name from multiple tables, the statement must precede those column names with their table names and a dot (e.g., authors.authorID ).

47.  1992-2007 Pearson Education, Inc. All rights reserved. 47 Common Programming Error 25.5 Failure to qualify names for columns that have the same name in two or more tables is an error.

48.  2005 Pearson Education, Inc. All rights reserved. 48 25.4.5 INSERT Statement Insert a row into a table – INSERT INTO tableName ( columnName1, …, columnNameN ) VALUES ( value1, …, valueN ) INSERT INTO authors ( firstName, lastName ) VALUES ( ‘Sue’, ‘Smith’ )

49.  1992-2007 Pearson Education, Inc. All rights reserved. 49 Fig. 25.20 | Sample data from table Authors after an INSERT operation.

50.  1992-2007 Pearson Education, Inc. All rights reserved. 50 Common Programming Error 25.6 It is normally an error to specify a value for an autoincrement column.

51.  1992-2007 Pearson Education, Inc. All rights reserved. 51 Common Programming Error 25.7 SQL uses the single-quote ( ' ) character as a delimiter for strings. To specify a string containing a single quote (e.g., O’Malley) in a SQL statement, the string must have two single quotes in the position where the single-quote character appears in the string (e.g., 'O''Malley' ). The first of the two single-quote characters acts as an escape character for the second. Not escaping single-quote characters in a string that is part of a SQL statement is a SQL syntax error.

52.  2005 Pearson Education, Inc. All rights reserved. 52 25.4.6 UPDATE Statement Modify data in a table – UPDATE tableName SET columnName1 = value1, …, columnNameN = valueN WHERE criteria UPDATE authors SET lastName = ‘Jones’ WHERE lastName = ‘Smith’ AND firstName = ‘Sue’

53.  1992-2007 Pearson Education, Inc. All rights reserved. 53 Fig. 25.21 | Sample data from table authors after an UPDATE operation.

54.  2005 Pearson Education, Inc. All rights reserved. 54 25.4.7 DELETE Statement Remove data from a table – DELETE FROM tableName WHERE criteria DELETE FROM authors WHERE lastName = ‘Jones’ AND firstName = ‘Sue’

55.  1992-2007 Pearson Education, Inc. All rights reserved. 55 Fig. 25.22 | Sample data from table authors after a DELETE operation.

56.  2005 Pearson Education, Inc. All rights reserved. 56 25.5 Instructions to Install MySQL and MySQL Connector/J Install MySQL – Platform-specific installation requirements: dev.mysql.com/doc/refman/5.0/en/general- installation-issues.html – Download your platform’s installer from: dev.mysql.com/downloads/mysql/5.0.html Need only the Windows Essentials package on Microsoft Windows – Follow installation instructions for your platform: dev.mysql.com/doc/refman/5.0/en/installing. html

57.  2005 Pearson Education, Inc. All rights reserved. 57 25.5 Instructions to Install MySQL and MySQL Connector/J MySQL Server Instance Configuration Wizard – Click Next > then select Standard Configuration and click Next > again. – Not necessary to install MySQL as a Windows service for our examples Uncheck Install as a Windows Service Check Include Bin Directory in Windows PATH – Click Next > then click Execute to perform the server configuration. – Click Finish to close the wizard.

58.  2005 Pearson Education, Inc. All rights reserved. 58 25.5 Instructions to Install MySQL and MySQL Connector/J Install MySQL Connector/J – Must install Connector/J JDBC driver from: dev.mysql.com/downloads/connector/j/ 5.0.html – Download mysql-connector-java-5.0.4.zip – Extract mysql-connector-java-5.0.4.zip to your hard disk into the folder mysql-connector-java-5.0.4 – Documentation for MySQL Connector/J is in connector-j.pdf in the docs subdirectory of mysql-connector-java-5.0.4 – Docs also online at dev.mysql.com/doc/connector/j/en/ connector-j.html

59.  2005 Pearson Education, Inc. All rights reserved. 59 25.6 Instructions on Setting MySQL User Account Set up a user account – Start database server mysqld-nt.exe on Windows – Start the MySQL monitor mysql –h localhost –u root – Select the built-in database mysql USE mysql; – Add the user account jhtp7 and specify privileges create user 'jhtp7'@'localhost' identified by 'jhtp7'; grant select, insert, update, delete, create, drop, references, execute on *.* to 'jhtp7'@'localhost'; – Exit the MySQL Monitor exit;

60.  2005 Pearson Education, Inc. All rights reserved. 60 25.7 Creating Database books in MySQL Create books database – Open Command Prompt and change to the directory containing the SQL script books.sql – Start the MySQL monitor mysql –h localhost –u jhtp7 –p – Execute the script source books.sql; – Exit the MySQL Monitor exit;

61.  2005 Pearson Education, Inc. All rights reserved. 61 25.8 Manipulating Databases with JDBC Connect to a database Query the database Display the results of the query in JTable

62.  2005 Pearson Education, Inc. All rights reserved. 62 25.8.1 Connecting to and Querying a Database DisplayAuthors – Retrieves the entire authors table – Displays the data in the standard output stream – Example illustrates Connect to the database Query the database Process the result

63.  1992-2007 Pearson Education, Inc. All rights reserved. 63 Outline DisplayAuthors.java (1 of 3 ) Imports for the JDBC classes and interfaces from package java.sql Declare a String constant that specifies the JDBC driver’s class name Loads the class definition for the database driver. Declare a String constant that specifies the database URL

64.  1992-2007 Pearson Education, Inc. All rights reserved. 64 Outline DisplayAuthors.java (2 of 3 ) Invokes Connection method createStatement to obtain an object that implements interface Statement. Use the Statement object’s executeQuery method to execute a query that selects all the author information from table authors. Obtains the metadata for the ResultSet. Uses ResultSetMetaData method getColumnCount to retrieve the number of columns in the ResultSet. Obtain column name using method getColumnName Position the ResultSet cursor to the first row in the ResultSet with method next Extract the contents of one column in the current row Initialize a Connection reference called connection.

65.  1992-2007 Pearson Education, Inc. All rights reserved. 65 Outline DisplayAuthors.java (3 of 3 ) Catch SQLException, which is thrown if the query execution or ResultSet process fails ClassNotFoundException is thrown if the class loader cannot locate the driver class Close the Statement and the database Connection.

66.  1992-2007 Pearson Education, Inc. All rights reserved. 66 Software Engineering Observation 25.4 Most major database vendors provide their own JDBC database drivers, and many third-party vendors provide JDBC drivers as well. For more information on JDBC drivers, visit the Sun Microsystems JDBC Web site, servlet.java.sun.com/products/ jdbc/drivers.

67.  1992-2007 Pearson Education, Inc. All rights reserved. 67 Software Engineering Observation 25.5 Most database management systems require the user to log in before accessing the database contents. DriverManager method getConnection is overloaded with versions that enable the program to supply the user name and password to gain access.

68.  1992-2007 Pearson Education, Inc. All rights reserved. 68 Fig. 25.24 | Popular JDBC database URL formats.

69.  1992-2007 Pearson Education, Inc. All rights reserved. 69 Software Engineering Observation 25.6 Metadata enables programs to process ResultSet contents dynamically when detailed information about the ResultSet is not known in advance.

70.  1992-2007 Pearson Education, Inc. All rights reserved. 70 Common Programming Error 25.8 Initially, a ResultSet cursor is positioned before the first row. Attempting to access a ResultSet ’s contents before positioning the ResultSet cursor to the first row with method next causes a SQLException.

71.  1992-2007 Pearson Education, Inc. All rights reserved. 71 Performance Tip 25.1 If a query specifies the exact columns to select from the database, the ResultSet contains the columns in the specified order. In this case, using the column number to obtain the column’s value is more efficient than using the column name. The column number provides direct access to the specified column. Using the column name requires a search of the column names to locate the appropriate column.

72.  1992-2007 Pearson Education, Inc. All rights reserved. 72 Common Programming Error 25.9 Specifying column number 0 when obtaining values from a ResultSet causes a SQLException.

73.  1992-2007 Pearson Education, Inc. All rights reserved. 73 Common Programming Error 25.10 Attempting to manipulate a ResultSet after closing the Statement that created the ResultSet causes a SQLException. The program discards the ResultSet when the corresponding Statement is closed.

74.  1992-2007 Pearson Education, Inc. All rights reserved. 74 Software Engineering Observation 25.7 Each Statement object can open only one ResultSet object at a time. When a Statement returns a new ResultSet, the Statement closes the prior ResultSet. To use multiple ResultSet s in parallel, separate Statement objects must return the ResultSet s.

75.  2005 Pearson Education, Inc. All rights reserved. 75 25.8.2 Querying the books Database Allow the user to enter any query into the program Display the results of a query in a JTable

76.  1992-2007 Pearson Education, Inc. All rights reserved. 76 Outline ResultSetTable Model.java (1 of 7 ) Class ResultSetTableModel extends class AbstractTableModel, which implements interface TableModel. Instance variable keeps track of database connection status

77.  1992-2007 Pearson Education, Inc. All rights reserved. 77 Outline ResultSetTable Model.java (2 of 7 ) Establishes a connection to the database. Invokes Connection method createStatement to create a Statement object. Constructor accepts five String arguments—the driver class name, the database URL, the username, the password and the default query to perform Indicate that connect to database is successful Invokes ResultSetTableModel method setQuery to perform the default query.

78.  1992-2007 Pearson Education, Inc. All rights reserved. 78 Outline ResultSetTable Model.java (3 of 7 ) Override method getColumnClass to obtain a Class object that represents the superclass of all objects in a particular column Verify database connection status Loads the class definition for the class and returns the corresponding Class object. Returns the default type. Obtains the fully qualified class name for the specified column. Override method getColumnCount to obtain the number of columns in the model’s underlying ResultSet

79.  1992-2007 Pearson Education, Inc. All rights reserved. 79 Outline ResultSetTable Model.java (4 of 7 ) Obtains the number of columns in the ResultSet. Override method getColumnName to obtain the name of the column in the model’s underlying ResultSet Obtains the column name from the ResultSet.

80.  1992-2007 Pearson Education, Inc. All rights reserved. 80 Outline ResultSetTable Model.java (5 of 7 ) Override method getColumnCount to obtain the number of rows in the model’s underlying ResultSet Uses ResultSet method absolute to position the ResultSet cursor at a specific row. Override method getValueAt to obtain the Object in a particular row and column of the model’s underlying ResultSet Uses ResultSet method getObject to obtain the Object in a specific column of the current row.

81.  1992-2007 Pearson Education, Inc. All rights reserved. 81 Outline ResultSetTable Model.java (6 of 7 ) Executes the query to obtain a new ResultSet. Uses ResultSet method last to position the ResultSet cursor at the last row in the ResultSet. Uses ResultSet method getRow to obtain the row number for the current row in the ResultSet. Invokes method fireTableAStructureChanged to notify any JTable using this ResultSetTableModel object as its model that the structure of the model has changed.

82.  1992-2007 Pearson Education, Inc. All rights reserved. 82 Outline ResultSetTable Model.java (7 of 7 ) Method disconnectFromDatabase implement an appropriate termination method for class ResultSetTableModel Verify whether the connection is already terminated Close the Statement and Connection if a ResultSetTableModel object is garbage collected. Set connectedToDatabase to false to ensure that clients do not use an instance of ResultSetTableModel after that instance has already been terminated

83.  1992-2007 Pearson Education, Inc. All rights reserved. 83 Fig. 25.26 | ResultSet constants for specifying ResultSet type.

84.  1992-2007 Pearson Education, Inc. All rights reserved. 84 Portability Tip 25.3 Some JDBC drivers do not support scrollable ResultSet s. In such cases, the driver typically returns a ResultSet in which the cursor can move only forward. For more information, see your database driver documentation.

85.  1992-2007 Pearson Education, Inc. All rights reserved. 85 Portability Tip 25.4 Some JDBC drivers do not support updatable ResultSet s. In such cases, the driver typically returns a read-only ResultSet. For more information, see your database driver documentation.

86.  1992-2007 Pearson Education, Inc. All rights reserved. 86 Common Programming Error 25.11 Attempting to update a ResultSet when the database driver does not support updatable ResultSet s causes SQLFeatureNotSupportedException s.

87.  1992-2007 Pearson Education, Inc. All rights reserved. 87 Common Programming Error 25.12 Attempting to move the cursor backward through a ResultSet when the database driver does not support backward scrolling causes a SQLException.

88.  1992-2007 Pearson Education, Inc. All rights reserved. 88 Fig. 25.27 | ResultSet constants for specifying result properties.

89.  1992-2007 Pearson Education, Inc. All rights reserved. 89 Outline DisplayQuery Results.java (1 of 8 ) Declare the database driver class name, database URL, username and password for accessing the database

90.  1992-2007 Pearson Education, Inc. All rights reserved. 90 Outline DisplayQuery Results.java (2 of 8 ) Declare the default queryDeclare tableModel to be a reference to ResultSetTableModel Create TableModel for results of default query “SELECT * FROM authors”

91.  1992-2007 Pearson Education, Inc. All rights reserved. 91 Outline DisplayQuery Results.java (3 of 8 ) Create JTable delegate for tableModel

92.  1992-2007 Pearson Education, Inc. All rights reserved. 92 Outline DisplayQuery Results.java (4 of 8 ) Register an event handler for the submitButton that the user clicks to submit a query to the database Invoke ResultSetTableModel method setQuery to execute the new query

93.  1992-2007 Pearson Education, Inc. All rights reserved. 93 Outline DisplayQuery Results.java (5 of 8 ) Ensure that the database connection is closed Set up TableRowSorter No filter initially

94.  1992-2007 Pearson Education, Inc. All rights reserved. 94 Outline DisplayQuery Results.java (6 of 8 ) Set filter using regular expression

95.  1992-2007 Pearson Education, Inc. All rights reserved. 95 Outline DisplayQuery Results.java (7 of 8 ) Ensure that the database connection is closed Ensure that the database connection is closed when window is closed

96.  1992-2007 Pearson Education, Inc. All rights reserved. 96 Outline DisplayQuery Results.java (8 of 8 )

97.  2005 Pearson Education, Inc. All rights reserved. 97 25.10 RowSet Interface Interface RowSet – Configures the database connection automatically – Prepares query statements automatically – Provides set methods to specify the properties needed to establish a connection – Part of the javax.sql package Two types of RowSet – Connected RowSet Connects to database once and remain connected – Disconnected RowSet Connects to database, executes a query and then closes connection

98.  2005 Pearson Education, Inc. All rights reserved. 98 25.10 RowSet Interface (Cont.) Package javax.sql.rowset – JdbcRowSet Connected RowSet Wrapper around a ResultSet Scrollable and updatable by default – CachedRowSet Disconnected RowSet Cache the data of ResultSet in memory Scrollable and updatable by default Serializable – Can be passed between Java application Limitation – Amount of data that can be stored in memory is limited

99.  1992-2007 Pearson Education, Inc. All rights reserved. 99 Portability Tip 25.5 A RowSet can provide scrolling capability for drivers that do not support scrollable ResultSet s.

100.  1992-2007 Pearson Education, Inc. All rights reserved. 100 Outline JdbcRowSetTest.java (1 of 3 )

101.  1992-2007 Pearson Education, Inc. All rights reserved. 101 Outline JdbcRowSetTest.java (2 of 3 ) Use Sun’s reference implementation of JdbcRowSet interface ( JdbcRowSetImpl ) to create a JdbcRowSet object Invoke JdbcRowSet method setUrl to specify the database URL Invoke JdbcRowSet method setUsername to specify the username Invoke JdbcRowSet method setUsername to specify the password Invoke JdbcRowSet method setCommand to specify the query Invoke JdbcRowSet method execute to execute the query

102.  1992-2007 Pearson Education, Inc. All rights reserved. 102 Outline JdbcRowSetTest.java (3 of 3 )

103.  2005 Pearson Education, Inc. All rights reserved. 103 25.11 Java DB/Apache Derby As of JDK 6, Sun Microsystems now bundles the open-source, pure Java database Java DB (the Sun branded version of Apache Derby) with the JDK We use the embedded version of Java DB There is also a network version that executes similarly to the MySQL DBMS introduced earlier in the chapter

104.  2005 Pearson Education, Inc. All rights reserved. 104 25.11 Java DB/Apache Derby Java DB comes with several batch files to configure and run it First set the environment variable JAVA_HOME to refer to the JDK’s C:\Program Files\Java\jdk1.6.0 installation directory Open the batch file setEmbeddedCP.bat (located in C:\Program Files\Java\jdk1.6.0\db\frameworks\embedded\bin ) in a text editor such as Notepad Locate the line rem set DERBY_INSTALL= and change it to set DERBY_INSTALL=C:\Program Files\Java\jdk1.6.0\db Also, comment out the line @FOR %X in ("%DERBY_HOME%") DO SET DERBY_HOME=%~sX by preceding it with REM Save your changes and close this file

105.  2005 Pearson Education, Inc. All rights reserved. 105 25.11 Java DB/Apache Derby Change directories to C:\Program Files\Java\ jdk1.6.0\db\frameworks\embedded\bin\. Then, type setEmbeddedCP.bat and press Enter to set the environment variables required by Java DB. Embedded Java DB database must reside in the same location as the application that manipulates the database – Change to the directory that contains the code for Figs. 25.30– 25.32 Execute the command "C:\Program Files\Java\jdk1.6.0\db\frameworks\embedded\bin\ij" to start the command-line tool for interacting with Java DB. The double quotes are necessary because the path contains a space.

106.  2005 Pearson Education, Inc. All rights reserved. 106 25.11 Java DB/Apache Derby At the ij> prompt type connect 'jdbc:derby:AddressBook;create=true; user=jhtp7;password=jhtp7'; to create the AddressBook database in the current directory. This command also creates the user jhtp7 with the password jhtp7 for accessing the database. To create the database table and insert sample data in the database type run 'address.sql'; To terminate the Java DB command-line tool, type exit;

107.  2005 Pearson Education, Inc. All rights reserved. 107 25.12 PreparedStatements PreparedStatement s execute more efficiently than Statement objects PreparedStatement s can specify parameters

108.  2005 Pearson Education, Inc. All rights reserved. 108 25.12 PreparedStatements PreparedStatement to locate all book titles for an author with a specific last name and first name, and to execute that query for several authors: – PreparedStatement authorBooks = connection.prepareStatement( "SELECT lastName, firstName, title " + "FROM authors INNER JOIN authorISBN " + "ON authors.authorID=authorISBN.authorID " + "INNER JOIN titles " + "ON authorISBN.isbn=titles.isbn " + "WHERE lastName = ? AND firstName = ?" ); Question marks (?) are placeholders for values that will be passed as part of the query to the database

109.  2005 Pearson Education, Inc. All rights reserved. 109 25.12 PreparedStatements Program must specify the parameter values by using the PreparedStatement interface’s set methods. For the preceding query, both parameters are strings that can be set with PreparedStatement method setString as follows: authorBooks.setString( 1, "Deitel" ); authorBooks.setString( 2, "Paul" ); setString automatically escapes String parameter values as necessary (e.g., the quote in the name O’Brien) More info at java.sun.com/javase/6/docs/api/ java/sql/PreparedStatement.html

110.  1992-2007 Pearson Education, Inc. All rights reserved. 110 Performance Tip 25.2 PreparedStatement s are more efficient than Statement s when executing SQL statements multiple times and with different parameter values.

111.  1992-2007 Pearson Education, Inc. All rights reserved. 111 Error-Prevention Tip 25.1 Use PreparedStatement s with parameters for queries that receive String values as arguments to ensure that the String s are quoted properly in the SQL statement.

112.  1992-2007 Pearson Education, Inc. All rights reserved. 112 Outline Person.java (1 of 3 )

113.  1992-2007 Pearson Education, Inc. All rights reserved. 113 Outline Person.java (2 of 3 )

114.  1992-2007 Pearson Education, Inc. All rights reserved. 114 Outline Person.java (3 of 3 )

115.  1992-2007 Pearson Education, Inc. All rights reserved. 115 Outline PersonQueries.java (1 of 7 ) All program to use PreparedStatement s Declare PreparedStatement s Note that we do not load the Java DB driver first. JDBC 4’s automatic driver discovery is used here.

116.  1992-2007 Pearson Education, Inc. All rights reserved. 116 Outline PersonQueries.java (2 of 7 ) Configure each PreparedStatement. Each ? represents a parameter.

117.  1992-2007 Pearson Education, Inc. All rights reserved. 117 Outline PersonQueries.java (3 of 7 ) Executes the query in PreparedStatement selectAllPeople. Process the ResultSet.

118.  1992-2007 Pearson Education, Inc. All rights reserved. 118 Outline PersonQueries.java (4 of 7 ) Specify the parameter to PreparedStatement selectPeopleByLastName. Executes the query in PreparedStatement selectPeopleByLastName.

119.  1992-2007 Pearson Education, Inc. All rights reserved. 119 Outline PersonQueries.java (5 of 7 ) Process the ResultSet.

120.  1992-2007 Pearson Education, Inc. All rights reserved. 120 Outline PersonQueries.java (6 of 7 ) Specify the parameters to PreparedStatement insertNewPerson. Executes the insert operation in PreparedStatement insertNewPerson.

121.  1992-2007 Pearson Education, Inc. All rights reserved. 121 Outline PersonQueries.java (7 of 7 )

122.  1992-2007 Pearson Education, Inc. All rights reserved. 122 Outline AddressBook Display.java (1 of 14 )

123.  1992-2007 Pearson Education, Inc. All rights reserved. 123 Outline AddressBook Display.java (2 of 14 )

124.  1992-2007 Pearson Education, Inc. All rights reserved. 124 Outline AddressBook Display.java (3 of 14 )

125.  1992-2007 Pearson Education, Inc. All rights reserved. 125 Outline AddressBook Display.java (4 of 14 )

126.  1992-2007 Pearson Education, Inc. All rights reserved. 126 Outline AddressBook Display.java (5 of 14 )

127.  1992-2007 Pearson Education, Inc. All rights reserved. 127 Outline AddressBook Display.java (6 of 14 )

128.  1992-2007 Pearson Education, Inc. All rights reserved. 128 Outline AddressBook Display.java (7 of 14 )

129.  1992-2007 Pearson Education, Inc. All rights reserved. 129 Outline AddressBook Display.java (8 of 14 )

130.  1992-2007 Pearson Education, Inc. All rights reserved. 130 Outline AddressBook Display.java (9 of 14 )

131.  1992-2007 Pearson Education, Inc. All rights reserved. 131 Outline AddressBook Display.java (10 of 14 ) Executes the query in PreparedStatement selectPeopleByLastName from class PersonQueries.

132.  1992-2007 Pearson Education, Inc. All rights reserved. 132 Outline AddressBook Display.java (11 of 14 )

133.  1992-2007 Pearson Education, Inc. All rights reserved. 133 Outline AddressBook Display.java (12 of 14 ) Executes the query in PreparedStatement selectAllPeople from class PersonQueries.

134.  1992-2007 Pearson Education, Inc. All rights reserved. 134 Outline AddressBook Display.java (13 of 14 ) Executes the insert operation in PreparedStatement insertNewPerson from class PersonQueries.

135.  1992-2007 Pearson Education, Inc. All rights reserved. 135 Outline AddressBook Display.java (14 of 14 )

136.  2005 Pearson Education, Inc. All rights reserved. 136 25.12 Stored Procedures Stored procedures – Store SQL statements in a database – Invoke SQL statements by programs accessing the database Interface CallableStatement – Receive arguments – Output parameters

137.  1992-2007 Pearson Education, Inc. All rights reserved. 137 Portability Tip 25.6 Although the syntax for creating stored procedures differs across database management systems, the interface CallableStatement provides a uniform interface for specifying input and output parameters for stored procedures and for invoking stored procedures.

138.  1992-2007 Pearson Education, Inc. All rights reserved. 138 Portability Tip 25.7 According to the Java API documentation for interface CallableStatement, for maximum portability between database systems, programs should process the update counts or ResultSet s returned from a CallableStatement before obtaining the values of any output parameters.

139.  2005 Pearson Education, Inc. All rights reserved. 139 25.13 Transaction Processing Many applications require guarantees that a series of database insertions, updates and deletions executes properly before the applications continue processing the next database operation Enables a program that interacts with a database to treat a database operation (or set of operations) as a single operation – Known as an atomic operation or a transaction – At the end of a transaction, decide to commit or roll back

140.  2005 Pearson Education, Inc. All rights reserved. 140 25.13 Transaction Processing Committing a transaction finalizes the database operation(s); all insertions, updates and deletions performed as part of the transaction cannot be reversed without performing a new database operation Rolling back a transaction leaves the database in its state prior to the database operation

141.  2005 Pearson Education, Inc. All rights reserved. 141 25.13 Transaction Processing Methods of interface Connection – setAutoCommit specifies whether each SQL statement commits after it completes (a true argument) or if several SQL statements should be grouped as a transaction (a false argument) If the argument to setAutoCommit is false, the program must follow the last SQL statement in the transaction with a call to Connection method commit or rollback – getAutoCommit determines the autocommit state for the Connection.