Home > Web Front-end > HTML Tutorial > com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column '' in 'field list'_html/css_WEB-ITnose

com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column '' in 'field list'_html/css_WEB-ITnose

WBOY
Release: 2016-06-24 12:03:58
Original
3125 people have browsed it

严重: Servlet.service() for servlet jsp threw exception
com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column '??????' in 'field list'
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
    at com.mysql.jdbc.Util.getInstance(Util.java:381)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1030)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:956)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3491)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3423)
    at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1936)
    at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2060)
    at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2536)
    at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1564)
    at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1485)
    at org.apache.jsp.insert_jsp._jspService(insert_jsp.java:100)
    at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:723)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:388)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:723)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
    at org.apache.coyote.http11.Http11NioProcessor.process(Http11NioProcessor.java:891)
    at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:750)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:2282)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
    at java.lang.Thread.run(Thread.java:619)

 

------解决方案--------------------
这个错很简单
从这代码可以看出 : String sql="INSERT INTO STUDENT VALUES(" id "," name ")";
如果 我的 id=1,name=adf 那么组合成的字符串就是
INSERT INTO STUDENT VALUES(1,adf ) 你可以尝试去执行这句SQL,肯定会报错
正确的写法应该是 INSERT INTO STUDENT VALUES(1,'adf' ); --数字类型可以不用加单引号 

所以
应该是 String sql="INSERT INTO STUDENT VALUES(" id ",'" name "')";
------解决方案--------------------
遇见这种数据库语句的问题,考虑到语句有字符串的的拼接,你可以用
System.out.print(sql);先将你的语句输出,这样就很容易发现有没有错误。

source:php.cn
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Popular Tutorials
More>
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template