PreparedStatement抛出语法错误

我正在使用PreparedStatements准备一个查询，当我用条件参数硬编码查询时它运行正常。

如果参数是从setString（）方法传递的，则抛出错误。

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，我的查询上面看起来很好。

 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("\n\n"+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？

Answer 1

删除此行中的参数：

 rs= pst.executeQuery(query); 

一定是

 rs= pst.executeQuery(); 

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

execute(String sql)inheritance自Statement并将执行satement（sql）而不做好准备。

Answer 2

从中删除参数

 rs= pst.executeQuery(query); 

改成

 rs= pst.executeQuery(); 

如果你在pst.executeQuery(query);传递查询pst.executeQuery(query); 作为参数，此传递的query字符串优先于您在conn.prepareStatement(query);传递的query字符串conn.prepareStatement(query); 并且因为在query （ select * from linkedin_page_messages where company_id = ? ）你dint传递参数你得到错误。