我在index.jsp上写了一个表单
<form action="/jdbc/servlet/Jdbc" method="post">
ID<input type="text" name="id">
NAME<input type="text" name="user">
<input type="submit" value="submit">
</form>点击提交后转到jdbc这个servlet中处理数据库的插入:
String id=request.getParameter("id");
String name=request.getParameter("user");
String db="com.mysql.jdbc.Driver";
String dbName="jdbc:mysql://localhost:3306/student";
String dbUser="root",dbPass="itelly";
String sql="INSERT INTO STUDENT VALUES("+id+","+name+")";
Connection connection=null;
Statement statement=null;
try {
Class.forName(db);
connection=DriverManager.getConnection(dbName, dbUser, dbPass);
statement=connection.createStatement();
statement.executeUpdate(sql);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
try {
statement.close();
connection.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}可是执行后数据库里面怎么没有插入成功呢?
ps.我这个数据库.用户名.密码都是正确的.myeclipse提示:
com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 'adf' 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:411)
at com.mysql.jdbc.Util.getInstance(Util.java:386)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1052)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4096)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4028)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2490)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2651)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2677)
at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1748)
at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1665)
at com.haolly.Jdbc.doPost(Jdbc.java:101)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:641)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:929)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1002)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:585)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:1813)
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:662)
<form action="/jdbc/servlet/Jdbc" method="post">
ID<input type="text" name="id">
NAME<input type="text" name="user">
<input type="submit" value="submit">
</form>点击提交后转到jdbc这个servlet中处理数据库的插入:
String id=request.getParameter("id");
String name=request.getParameter("user");
String db="com.mysql.jdbc.Driver";
String dbName="jdbc:mysql://localhost:3306/student";
String dbUser="root",dbPass="itelly";
String sql="INSERT INTO STUDENT VALUES("+id+","+name+")";
Connection connection=null;
Statement statement=null;
try {
Class.forName(db);
connection=DriverManager.getConnection(dbName, dbUser, dbPass);
statement=connection.createStatement();
statement.executeUpdate(sql);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
try {
statement.close();
connection.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}可是执行后数据库里面怎么没有插入成功呢?
ps.我这个数据库.用户名.密码都是正确的.myeclipse提示:
com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 'adf' 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:411)
at com.mysql.jdbc.Util.getInstance(Util.java:386)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1052)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4096)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4028)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2490)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2651)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2677)
at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1748)
at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1665)
at com.haolly.Jdbc.doPost(Jdbc.java:101)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:641)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:929)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1002)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:585)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:1813)
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:662)
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+"')";
这么明显的错误信息!!!
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。