如何使用java变量将值插入mysql表？

Question

嗨,我想将值插入到mysql表中.我正在尝试这段代码.我已将值赋给变量,我想将该变量传递给该insert语句.它是否正确？

code
    int tspent = "1";
    String pid = "trng";
    String tid = "2.3.4";
    String rid = "tup";
    String des = " polish my shoes!";

    INSERT INTO `time_entry`(pid,tid,rid,tspend,description) VALUE ('"+pid+"','"+tid+"','"+rid+"',"+tspent+",'"+des+"');

这是我尝试过的,但我无法插入值

try
       {
           conn=DBMgr.openConnection();     
           String sqlQuery = "INSERT INTO `time_entry`(pid,tid,rid,tspend,description) VALUE ('"+pid+"','"+tid+"','"+rid+"',"+tspent+",'"+des+"');";
           st = conn.createStatement();
           rs = st.executeQuery(sqlQuery); 
       }

Answer 1

executeUpdate()只要查询是SQL数据操作语言语句,就应该使用方法.此外,您当前的查询易受SQL注入攻击.

你应该使用PreparedStatement:

PreparedStatement pstmt = conn.prepareStatement("INSERT INTO `time_entry`(pid,tid,rid,tspend,description) VALUES (?, ?, ?, ?, ?)");\

然后在这些索引处设置变量:

pstmt.setString(1, pid);
// Similarly for the remaining 4 

// And then do an executeUpdate
pstmt.executeUpdate();

Answer 2

试试这个,

    String driver="com.mysql.jdbc.Driver";
    String url="jdbc:mysql://localhost:3306/dbname";
    String uname="username";
    String pass="password";
    Class.forName(driver);
    Connection c=(Connection) DriverManager.getConnection(url,uname,pass);
    Statement s=c.createStatement();
    s.executeUpdate("INSERT INTO `time_entry`(pid,tid,rid,tspend,description) VALUE ('"+pid+"','"+tid+"','"+rid+"',"+tspent+",'"+des+"')");

Answer 3

使用PreparedStatement并使用其setXXX（）方法设置值。

PreparedStatement pstmt = con.prepareStatement("INSERT INTO `time_entry`
        (pid,tid,rid,tspend,description) VALUE 
        (?,?,?,?,?)");
pstmt.setString(1, pid );
pstmt.setString(2, tid);
pstmt.setString(3, rid);
pstmt.setInt(4, tspent);
pstmt.setString(5,des );
pstmt.executeUpdate();