PreparedStatement 抛出语法错误 [英] PreparedStatement throws syntax error

问题描述

我正在使用 PreparedStatements 准备一个查询，当我使用条件参数对 te 查询进行硬编码时，它运行良好.

Im preparing a query using PreparedStatements and it runs fine when i hardcode te query with the condition parameter.

但是如果参数是从 setString() 方法传递过来的，则会抛出错误.

but throws error , if the parameter is passed from setString() method.

com.mysql.jdbc.JDBC4PreparedStatement@2cf63e26: select * from linkedin_page_mess ages where company_id = '2414183' com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '?' at line 1

在错误日志中，上面我的查询看起来不错.

In the error log, above my query looks fine.

public JSONObject getLinkedInMessages(String compId)
    {
            linlogger.log(Level.INFO, "Called getLinkedInMessages method");
        Connection conn = null;
        Statement stmt = null;
        ResultSet rs = null;

        JSONObject resObj = new JSONObject();
        JSONArray tempArray = new JSONArray();
        try
        {
            conn = InitOrGetConnection();
            String query = "select * from linkedin_page_messages where company_id = ?";
            PreparedStatement pst=conn.prepareStatement(query);
            pst.setString(1, compId);
            System.out.println("

"+pst.toString());
            rs= pst.executeQuery(query);


             // process resultset logics
        }
       catch(Exception e)
        {   
            System.out.println(e);
            linlogger.log(Level.INFO, "Exception occured "+e.toString());
        }
    }

PreparedStatements 有什么问题吗?

Is there anything wrong with the PreparedStatements?

推荐答案

去掉这一行的参数:

rs= pst.executeQuery(query);

一定是

rs= pst.executeQuery();

因为语句是在PreparedStatement pst=conn.prepareStatement(query);

execute(String sql) 继承自 语句 并且会在没有准备好的情况下执行语句(sql).

execute(String sql) is inherited from Statement and will execute the satement (sql) without prepared it.

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