java - java中sql的字符串参数和SELECT准备语句

Question

我有问题>>

编程语言:java数据库:Mysql数据库

我编写了一个java代码，用于根据方法中的数据参数从数据库中检索记录>>

代码是:

public static void Get_patient_data(String Hospital1_ID,String Hospital2_ID {       
   try {
      Connection con = getConnection2();
      PreparedStatement statement = (com.mysql.jdbc.PreparedStatement)
         con.prepareStatement(
            "SELECT PatientGender "+
            "FROM patientcorepopulatedtable "+
               "WHERE PatientID = Hospital1_ID LIMIT 1" );
      ResultSet result = statement.executeQuery();
      ArrayList<String> array = new ArrayList<String>();
      while( result.next()) {
         System.out.print("the patient Gender is"  +
            result.getString("PatientGender"));
      }
   }
   catch(Exception e) {
      System.out.println("Error"+e);
   }
}

如您所见，问题是 Hospital1_ID 参数 .. 来自该方法，而 patientID 是表 patientcorepopulatedtable 中的一列 ...

= 等于运算符不起作用。

Answer 1

试试这个

String query =
   "SELECT PatientGender FROM patientcorepopulatedtable "+
      " WHERE PatientID = ? LIMIT ?";
      PreparedStatement preparedStmt = conn.prepareStatement(query);
      preparedStmt.setString   (1, Hospital1_ID);
      preparedStmt.setInt   (2, 1);
      preparedStmt.executeQuery();