jdbc mysql executeUpdate不能正常工作

Question

PreparedStatement  stmt1 = con.prepareCall("update khol SET emailcnf =  'ya' where khol.id = 
     (SELECT guiid.id FROM guiid WHERE guiid.gchbi = 'htg1' and guiid.typ = 'reg')");

System.out.println("rows COUNT "+stmt1.executeUpdate());

stmt1.close();

输出是：

  

行COUNT 0

0由executeUpdate返回并且当我直接运行相同的语句在Mysql中它工作正常。

Answer 1

您应该使用con.prepareStatement()代替con.prepareCall()

请查看以下链接，以帮助您了解createStatement() prepareSatement()和prepareCall()

之间的区别

http://javaconceptoftheday.com/statement-vs-preparedstatement-vs-callablestatement-in-java/

以下内容应该有效：

PreparedStatement  stmt1 = con.prepareStatement("update khol SET emailcnf =  'ya' where khol.id = 
            (SELECT guiid.id FROM guiid WHERE guiid.gchbi = 'htg1' and guiid.typ = 'reg')");

System.out.println("rows COUNT "+stmt1.executeUpdate());

stmt1.close();