Java sql delete row

Question

Hello I am trying to delete a row from my database. I am getting no errors but it is doing nothing, any help or advice would be great!

public static void DeleteRow(String name) {
    try {  
        Class.forName("com.mysql.jdbc.Driver");
        Connection connection = DriverManager.getConnection(url, username, password);

        PreparedStatement st = connection.prepareStatement("DELETE FROM Table WHERE name = " + name + ";");
        st.executeUpdate();
    } catch(Exception e) {
        System.out.println(e);
    }
}

What do you expect it to do? – Sotirios Delimanolis Feb 04 '14 at 04:13 — Sotirios Delimanolis, Feb 04 '14 at 04:13

score 23 · Accepted Answer · edited Dec 06 '19 at 10:41

23

I guess name is a varchar type in DB so do like this

PreparedStatement st = connection.prepareStatement("DELETE FROM Table WHERE name = '" + name + "';");

enclose name within single quotes '

Also this is not the way you are using is not the proper way of using Preparedstatement

Us the following way:

PreparedStatement st = connection.prepareStatement("DELETE FROM Table WHERE name = ?");
st.setString(1,name);
st.executeUpdate(); 

// your full code after Proper PreparedStatement

public static void DeleteRow(String name) {
    try {  
        Class.forName("com.mysql.jdbc.Driver");
        Connection connection = DriverManager.getConnection(url, username, password);
        PreparedStatement st = connection.prepareStatement("DELETE FROM Table WHERE name = ?");
        st.setString(1,name);
        st.executeUpdate(); 
    } catch(Exception e) {
        System.out.println(e);
    }
}

edited Dec 06 '19 at 10:41

Miss Chanandler Bong

4,081
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answered Feb 04 '14 at 04:14

SpringLearner

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1

@jeremyjjbrown no need to escape single quotes – SpringLearner Feb 04 '14 at 04:18
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'Table WHERE name = 'UserTest'' – user3268379 Feb 04 '14 at 04:23
@user3268379 what is your table name? Table is a reserved keyword in mysql – SpringLearner Feb 04 '14 at 04:26
@jeremyjjbrown yes thats why I mentioned that this is not the proper way of preparedstament and also I have suggested how to do – SpringLearner Feb 04 '14 at 04:27

jeremyjjbrown · Answer 2 · 2014-02-04T04:28:30.683

2

You should never create a SQL statement in Java with String concatenation, it will be vulnerable to sql injection. Please do it this way.

String selectSQL = "DELETE FROM Table WHERE name = ?";
connection.prepareStatement(selectSQL);
preparedStatement.setString(1, name);

edited Feb 04 '14 at 04:28

answered Feb 04 '14 at 04:21

jeremyjjbrown

7,772
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score 1 · Answer 3 · answered Nov 18 '16 at 10:11

          Class.forName("oracle.jdbc.driver.OracleDriver");
          Connection con = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:XE", "MANASH_APPN","MANASH");
          PreparedStatement ps = con.prepareStatement("delete from EMP21 where empid = ?");
           ps.setInt(1,90);
           ps.executeUpdate();
          con.commit();
          System.out.println("Records Delete Successfully....");
         con.close();

score 0 · Answer 4 · edited Dec 06 '19 at 10:38

0

Every open connection must be closed, or it won't get implemented and no errors will be displayed. First learned lesson.

public static void DeleteRow(String name) {
    try {  
        Class.forName("com.mysql.jdbc.Driver");
        Connection connection = DriverManager.getConnection(url, username, password);

        PreparedStatement st = connection.prepareStatement("DELETE FROM Table WHERE name = " + name + ";");
        st.executeUpdate(); 
        connection.close();
    } catch(Exception e) {
        System.out.println(e);
    }
}

Hope this helps

edited Dec 06 '19 at 10:38

Miss Chanandler Bong

4,081
10
26
36

answered Feb 04 '14 at 04:17

Sudharsun

741
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23

Your code is vulnerable to SQl injection. https://www.owasp.org/index.php/Preventing_SQL_Injection_in_Java – jeremyjjbrown Feb 04 '14 at 04:27

score 0 · Answer 5 · answered Jun 18 '14 at 06:07

0

try this bro. use Statement

Statement stmt = connection.createStatement();
String SQL = "DELETE FROM Table WHERE name = '"+name+"'";
stmt.executeUpdate(SQL);

answered Jun 18 '14 at 06:07

wrecklez

343
2
4

score -1 · Answer 6 · answered Nov 25 '15 at 21:08

-1

this will work String del="DELETE FROM table WHERE name =('" + name + "')";

:)

answered Nov 25 '15 at 21:08

Asif alam

1
6

Java sql delete row

6 Answers6