Question

I have 3 tables, called Drivers, Offences and Points and Sofar I’m using 3 sql Strings to insert and update data in the tables

String command1 = "INSERT INTO Drivers (IDNumber, FirstName, LastName) VALUES" + drivID + FName + LName;
String command2 = "INSERT INTO Offences(IDNumber, SpeedLimit, DriverSpeed, SeatBelt, DrunkenDriving, DriversLicense) VALUES" + drivID + intspeed + intDSpeed + strSeat + strDrunk + strLicense;
String command3 = "INSERT INTO DriverPoints(IDNumber, Points) VALUES" + drivID + intpoints;

Each table is coneccted to eachother through the primary key IDNumber

Is there a way instead of having 3 Sql commands/Strings where I can have only 1 but still be able to insert and update all 3 tables?

Answer 1

Roughtly your query should look like this:

SELECT d.IDNumber, d.FirstName, d.LastName, o.SpeedLimit, o.DriverSpeed, o.SeatBelt, o.DrunkenDriving, o.DriversLicense, p.Points 
  FROM Drivers d
JOIN Offences o on (d.IDNumber = o.IDNumber)
JOIN DriverPoints p on (d.IDNumber = p.IDNumber)
WHERE (...) -- Whathever where condition you like

This will read everything.

For updating you have to perform 3 distinct updates statements or use a stored procedure or a view, but this really depends on the database you’re using.

EDIT: for insert I suggest you to use PreparedStatements

String command1 = "INSERT INTO Drivers (IDNumber, FirstName, LastName) VALUES (?, ?, ?)";
PreparedStatement ps = connection.prepareStatement(command1);
ps.setInteger(1, drivID );
ps.setString(2, FName );
ps.setString(3, LName );
ps.execute();