Summary: This tutorial walks you through 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. If you want the statement to take parameters, 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 warehouse with id 3 in the warehouses table of the my.db database created in the creating table tutorial.
import java.sql.DriverManager;
import java.sql.SQLException;
public class Main {
public static void main(String[] args) {
var url = "jdbc:sqlite:my.db";
var sql = "DELETE FROM warehouses WHERE id = ?";
var id = 3;
try (var conn = DriverManager.getConnection(url);
var pstmt = conn.prepareStatement(sql)) {
pstmt.setInt(1, id);
// execute the delete statement
pstmt.executeUpdate();
} catch (SQLException e) {
System.err.println(e.getMessage());
}
}
}Code language: Java (java)Verify the deletion
First, use the following SELECT statement to check the warehouses table before executing the program:
SELECT
id,
name,
capacity
FROM
warehouses;Code language: SQL (Structured Query Language) (sql)Output:
id name capacity
-- ------------------ --------
1 Raw Materials 3000.0
2 Semifinished Goods 4000.0
3 Finished Products 5500.0Code language: CSS (css)Second, run the program.
Third, use the same SELECT statement above to query data from the warehouses table:
SELECT
id,
name,
capacity
FROM
warehouses;Output:
id name capacity
-- ------------------ --------
1 Raw Materials 3000.0
2 Semifinished Goods 4000.0Code language: CSS (css)The output shows that the row with id 2 is deleted.
In this tutorial, you have learned how to delete data in the SQLite database from the Java program.