Once you have created a Connection, you can begin using it to execute SQL statements. This is usually done via Statement objects. There are actually three kinds of statements in JDBC:


Represents a basic SQL statement


Represents a precompiled SQL statement, which can offer improved performance


Allows JDBC programs complete access to stored procedures within the database itself

We’re just going to discuss the Statement object for now; PreparedStatement and CallableStatement are covered in detail later in this chapter.

To get a Statement object, call the createStatement( ) method of a Connection:

Statement stmt = con.createStatement(  );

Once you have created a Statement, use it to execute SQL statements. A statement can either be a query that returns results or an operation that manipulates the database in some way. If you are performing a query, use the executeQuery( ) method of the Statement object:

ResultSet rs = stmt.executeQuery("SELECT * FROM CUSTOMERS");

Here we’ve used executeQuery( ) to run a SELECT statement. This call returns a ResultSet object that contains the results of the query (we’ll take a closer look at ResultSet in the next section).

Statement also provides an executeUpdate( ) method, for running SQL statements that don’t return results, such as the UPDATE and DELETE statements. executeUpdate( ) returns an integer that indicates the number of rows in the database that were altered.

If you don’t know whether ...

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