问题描述
对此有麻烦..我确定我缺少一些简单的东西，但是我只想要Java mysql select语句中的select语句的结果，但我不断得到:
Having trouble with this..I'm sure I'm missing something simple but I simply want the result of a select statement in a java mysql select statement but I keep getting:
com.mysql.jdbc.JDBC4ResultSet@1c190c99
这是我的代码:
PreparedStatement Findstatement;
Findstatement = con.prepareStatement("SELECT Code from DataMaster where DataName= (?) ");
Findstatement.setString(1, Name); // I have a variable in my file named 'Name'
ResultSet CodeAll = Findstatement.executeQuery();
System.out.println(CodeAll);
我已经尝试过int fundCode = fundCodeAll.getInt(1);在声明的结尾，但仍然没有运气.如何从select语句中获取结果的int值?
I've tried int fundCode = fundCodeAll.getInt(1); at the end of the statement but still no luck. How do I get the int value of the the result from the select statement?
推荐答案
您需要通过ResultSet#next()遍历ResultSet，然后通过任何ResultSet getter获取列值.
You need to iterate over the ResultSet by ResultSet#next() and then get the column values by any of the ResultSet getters.
resultSet = statement.executeQuery();
while (resultSet.next()) {
int code = resultSet.getInt("Code");
// ...
}
如果结果为零或很多，则可以将它们收集在List中.
If there are zero or many results, then you can collect them in a List.
List<Integer> codes = new ArrayList<Integer>();
// ...
resultSet = statement.executeQuery();
while (resultSet.next()) {
codes.add(resultSet.getInt("Code"));
}
// ...
或者如果结果为零或一，则将while替换为if.
Or if there is zero or one result, then replace while by if.
int code = 0;
// ...
resultSet = statement.executeQuery();
if (resultSet.next()) {
code = resultSet.getInt("Code");
}
// ...