Java Programming with Oracle JDBC

Chapter 9. Statements

Now that you have a firm understanding of how to create a Connection object for each of the four types of clients outlined in Chapter 1, and you have the DDL to create the example HR database to use as a context for the chapters on relational SQL, we’re ready to change our focus from the Connection object to the Statement object. The Statement object, which you’ll create using a Connection object, allows you to execute both Data Definition Language (DDL) and Data Manipulation Language (DML) statements. The Statement object is the most dynamic of the JDBC objects, because you can use its execute( ) method to execute any valid SQL statement. If you use the execute( ) method, you can use its return value at runtime to determine whether there is a result set and then use the Statement object’s getResultSet( ) method to retrieve the result set, or you can use the Statement object’s getUpdateCount( ) method at runtime to determine the number of rows affected by your statement. For most situations, however, you won’t need that much flexibility. Instead, you’ll need to insert rows into a table, update or delete rows in a table, or select rows from a table. To that end, you’ll most often use one of the Statement object’s other two execute methods, executeUpdate( ) and executeQuery( ) .

In this chapter, we’ll start by covering how to create a Statement object from a Connection object. Then we’ll see how to use the execute( ) method to execute the DDL from Chapter 8 ...