Summary: this tutorial walks you through the steps of deleting data in a table from a Java program using JDBC.
To delete one or more rows of a database table from a Java program, you use the following steps:
- First, create a database connection to the SQLite database.
- Next, prepare the DELETE statement. In case you want the statement takes parameters, you use the question mark (?) placeholder inside the statement.
- Then, create a new instance of the
PreparedStatementclass by calling theprepareStatement()method of theConnectionobject. - After that, supply values in place of the question mark placeholder using the set* method of the
PreparedStatementobject e.g.,setInt(),setString(), etc. - Finally, execute the
DELETEstatement by calling theexecuteUpdate()method of thePreparedStatementobject.
The following program deletes the row with id 3 in the warehouses table of the test.db database that we created in the creating table tutorial.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 | package net.sqlitetutorial; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.SQLException; /** * * @author sqlitetutorial.net */ public class DeleteApp { /** * Connect to the test.db database * * @return the Connection object */ private Connection connect() { // SQLite connection string String url = "jdbc:sqlite:C://sqlite/db/test.db"; Connection conn = null; try { conn = DriverManager.getConnection(url); } catch (SQLException e) { System.out.println(e.getMessage()); } return conn; } /** * Delete a warehouse specified by the id * * @param id */ public void delete(int id) { String sql = "DELETE FROM warehouses WHERE id = ?"; try (Connection conn = this.connect(); PreparedStatement pstmt = conn.prepareStatement(sql)) { // set the corresponding param pstmt.setInt(1, id); // execute the delete statement pstmt.executeUpdate(); } catch (SQLException e) { System.out.println(e.getMessage()); } } /** * @param args the command line arguments */ public static void main(String[] args) { DeleteApp app = new DeleteApp(); // delete the row with id 3 app.delete(3); } } |
First, you use the following SELECT statement TO check the warehouses table before executing the delete program.
1 2 3 4 5 6 | SELECT id, name, capacity FROM warehouses; |
Second, run the DeleteApp program.
Third, use the same SELECT statement above to query data from the warehouses table.
In this tutorial, you have learned how to delete data in the SQLite database from the Java program.