Java · Theory

Java Database Connectivity with MySQL

Theory

246/270

Java Database Connectivity with MySQL

Database Connectivity with MySQL sits in JDBC — Java talking to a database with SQL. Five steps: driver → Connection → Statement/PreparedStatement → ResultSet → close (try-with-resources).

For Database Connectivity with MySQL: prefer PreparedStatement. Never paste user input into SQL with +. That is SQL injection.

Database Connectivity with MySQL session: connection URL, user, and password. ResultSet is read row by row with next(). Close everything when done.

Let's take this on the board with one tiny Main class — no extra files. Output: Asha scored 72 then Pass. Real Main. Swap marks/name to show one idea from Java Database Connectivity with MySQL. Start from main, go line by line, and stop at each print. That output is the proof for Database Connectivity with MySQL.

Exam tip

Explain Java Database Connectivity with MySQL as: definition → why → one code idea.

Example

// Java
public class Main {
  public static void main(String[] args) {
    int marks = 72;
    String name = "Asha";
    System.out.println(name + " scored " + marks);
    if (marks >= 40) System.out.println("Pass");
  }
}

Output: Asha scored 72 then Pass. Real Main. Swap marks/name to show one idea from Java Database Connectivity with MySQL.

Short notes

DefDatabase Connectivity with MySQL — JDBC = Java API to talk to a database with SQL.
FlowDatabase Connectivity with MySQL — driver → Connection → Statement → ResultSet → close.
RuleDatabase Connectivity with MySQL — prefer PreparedStatement. Use try-with-resources.
TrapDatabase Connectivity with MySQL — string-concatenating user input into SQL.

// Java public class Main { public static void main(String[] args) { int marks = 72; String name = "Asha"; System.out.println(name + " scored " + marks); if (marks >= 40) System.out.println("Pass"); } }

Java Database Connectivity with MySQL

Example

Short notes

Questions

Java Database Connectivity with MySQL

Example

Short notes

Questions