Java applications that hold some or all classes in the database have significant advantages over traditional SQL stored procedures. At an introductory level, however, it may be helpful to use the parallels with SQL stored procedures to demonstrate the capabilities of JDBC. In the following examples, we write Java classes that insert a row into the Department table.
As with other interfaces, SQL statements in JDBC can be either static or dynamic. Static SQL statements are constructed in the Java application, and sent to the database. The database server parses the statement, and selects an execution plan, and executes the statement. Together, parsing and selecting an execution plan are referred to as preparing the statement.
If a similar statement has to be executed many times (many inserts into one table, for example), there can be significant overhead in static SQL because the preparation step has to be executed each time.
In contrast, a dynamic SQL statement contains placeholders. The statement, prepared once using these placeholders, can be executed many times without the additional expense of preparing.
In this section we use static SQL. Dynamic SQL is discussed in a later section.
