Placeholder (?) when using PreparedStatement to execute an SQL statement (?) Usage, preparedstatement

Placeholder (?) when using PreparedStatement to execute an SQL statement (?) Usage, preparedstatement

1. Student database table

ID	Name	Gender

 

 

 

 

 

2. Java code

Public static void main (String [] args ){
Int _ id = 1;
String _ name = "zhangsan ";
String _ gender = "male ";
Connection con = null;
PreparedStatement ps = null;

Try {
// Load the driver
Class. forName ("com. mysql. jdbc. Driver ");
// Use the driver to create a connection
Con = DriverManager. getConnection ("jdbc: mysql: // localhost: 3306/mysql", "root", "111111 ");
// Define an SQL statement
String SQL = "insert into hehe values (?,?,?) ";
// Create an execution command object
Ps = con. prepareStatement (SQL );
// Set parameters
Ps. setInt (1, 1 );
Ps. setString (2, _ name );
Ps. setString (3, _ gender );

// Execute the command and accept the result
Int result=ps.exe cuteUpdate ();
System. out. println (result );

} Catch (ClassNotFoundException e ){

E. printStackTrace ();
} Catch (SQLException e ){

E. printStackTrace ();
} Finally {
Try {
If (null! = Ps)
Ps. close ();
If (null! = Con)
Con. close ();
} Catch (SQLException e ){

E. printStackTrace ();
}
}

}

}

3. The result is displayed.

ID	Name	Gender
1	Zhang San	Male