JDBC summary

We now have an overview of JDBC. The rest of this chapter will concentrate on writing abstractions that sit above JDBC, making database accesses feel more natural. Before we do this, let's summarize what we have seen so far.

We have used three JDBC classes:

• The Connection class represents a connection to a specific SQL database. Instantiate a connection as follows:

  import java.sql._
  Class.forName("com.mysql.jdbc.Driver")val connection = DriverManager.getConnection(
    "jdbc:mysql://127.0.0.1:3306/test",
    "root", // username when connecting
    "" // password
  )

  Our main use of Connection instances has been to generate PreparedStatement objects:

  connection.prepareStatement("SELECT * FROM physicists")

• A PreparedStatement instance represents a SQL statement about to be sent to the database. It also represents the template for a SQL statement with placeholders for values yet to be filled in. The class exposes the following methods:
  
• A ResultSet instance represents a set of rows returned by a SELECT or SHOW statement. ResultSet exposes methods to access fields in the current row:
  

The ResultSet instance exposes the .next method to move to the next row; .next returns true until the ResultSet has advanced to just beyond the last row.