Question

在我的数据库bean中，我有一段代码如下：

public Integer getTotalOrgPoints() {
        try {
            PreparedStatement stmt = ConnectionHandler.getConnection().prepareStatement(QUERY_TOTAL_ORG_SCORE);
            ResultSet rs = stmt.executeQuery();

            while (rs.next()) {
                totalOrgPoints = rs.getInt(1);
            }
        } catch (SQLException e) {
            System.out.println(e.getMessage());
        }

        return totalOrgPoints;
    }

对于语句QUERY_TOTAL_ORG_SCORE，如果我使用

SELECT SUM(users.score) 
FROM   user_organisation_relationships 
       INNER JOIN users 
               ON user_organisation_relationships.user_id = users.id 
WHERE  organisation_id = 1

它将返回该组织的值，但如果我使用

SELECT SUM(users.score) 
FROM   user_organisation_relationships 
       INNER JOIN users 
               ON user_organisation_relationships.user_id = users.id 
WHERE  organisation_id = ?

我什么都不知道为什么会发生这种情况？

Answer 1

添加此行以在executequery

之前绑定预准备语句的值

stmt.setInt(1, 1);

修改： -

PreparedStatement stmt = ConnectionHandler.getConnection().prepareStatement(QUERY_TOTAL_ORG_SCORE);
stmt.setInt(1, 1);
ResultSet rs = stmt.executeQuery();

数据库Java Bean SQL语句

1 个答案: