Java sql 删除行
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Java sql delete row
提问by user3268379
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!
您好，我正在尝试从我的数据库中删除一行。我没有收到任何错误，但它什么也没做，任何帮助或建议都会很棒！
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);
}
}
采纳答案by SpringLearner
I guess name is a varchar type in DB so do like this
我猜 name 是 DB 中的 varchar 类型，所以这样做
PreparedStatement st = connection.prepareStatement("DELETE FROM Table WHERE name = '" + name + "';");
enclose name within single quotes '
将名称括在单引号内 '
Also this is not the way you are using is not the proper way of using Preparedstatement
此外，这不是您使用的方式，也不是使用 Preparedstatement 的正确方式
Us the following way:
我们通过以下方式：
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);
}
}
回答by Sudharsun
Every open connection must be closed, or it won't get implemented and no errors will be displayed. First learned lesson.
每个打开的连接都必须关闭，否则将无法实现并且不会显示任何错误。第一次吸取教训。
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
希望这可以帮助
回答by jeremyjjbrown
You should never create a SQL statement in Java with String concatenation, it will be vulnerable to sql injection. Please do it this way.
永远不要用字符串连接在 Java 中创建 SQL 语句，它容易受到 sql 注入的攻击。请这样做。
String selectSQL = "DELETE FROM Table WHERE name = ?";
connection.prepareStatement(selectSQL);
preparedStatement.setString(1, name);
回答by wrecklez
try this bro. use Statement
试试这个兄弟。使用声明
Statement stmt = connection.createStatement();
String SQL = "DELETE FROM Table WHERE name = '"+name+"'";
stmt.executeUpdate(SQL);
回答by Asif alam
this will work String del="DELETE FROM table WHERE name =('" + name + "')";
这将起作用 String del="DELETE FROM table WHERE name =('" + name + "')";
:)
:)
回答by Manash Ranjan Dakua
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();
