JAVA DATABASE PROGRAMMING - Introduction to Java Programming: Comprehensive Version - page 1199

71 String courseId = tfCourseId.getText();
72

try {

73 preparedStatement.setString( 1 , ssn);

74 preparedStatement.setString( 2 , courseId);

75 ResultSet rset = preparedStatement.executeQuery(); execute statement

76
77 if (rset.next()) {
78 String lastName = rset.getString( 1 );
79 String mi = rset.getString( 2 );
80 String firstName = rset.getString( 3 );
81 String title = rset.getString( 4 );
82 String grade = rset.getString( 5 );
83
84 // Display result in a label
85 lblStatus.setText(firstName + " " + mi +
86 " " + lastName + "'s grade on course " + title + " is " +
87 grade);
88 } else {
89 lblStatus.setText( "Not found" );
90 }
91 }
92 catch (SQLException ex) {
93 ex.printStackTrace();
94 }
95 }
96 }

show result

This example does exactly the same thing as Listing 32.2 except that it uses the prepared
statement to dynamically set the parameters. The code in this example is almost the same as
in the preceding example. The new code is highlighted.
A prepared query string is defined in lines 56-59 with ssn and courseId as parameters.
An SQL prepared statement is obtained in line 62. Before executing the query, the actual
values of ssn and courseId are set to the parameters in lines 73-74. Line 75 executes the
prepared statement.

32.21

✓ ✓

Describe prepared statements. How do you create instances of
PreparedStatement ? How do you execute a PreparedStatement ? How do
you set parameter values in a PreparedStatement ?

Check

Point

32.22

What are the benefits of using prepared statements?

32.6 CallableStatement
CallableStatement enables you to execute SQL stored procedures.

Key
Point

The CallableStatement interface is designed to execute SQL-stored procedures. The
procedures may have IN , OUT or IN OUT parameters. An IN parameter receives a value
passed to the procedure when it is called. An OUT parameter returns a value after the proce-
dure is completed, but it doesn't contain any value when the procedure is called. An IN OUT
parameter contains a value passed to the procedure when it is called and returns a value after
it is completed. For example, the following procedure in Oracle PL/SQL has IN parameter p1 ,
OUT parameter p2 , and IN OUT parameter p3 .

IN parameter
OUT parameter
IN OUT parameter

create or replace procedure sampleProcedure
(p1 in varchar , p2 out number , p3 in out integer ) is
begin
/* do something */
end sampleProcedure;
/