Exception in thread "main" java.sql.SQLException
Exception in thread "main" java.sql.SQLException: Column 'user_name,28' not found.
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1055)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:956)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:926)
at com.mysql.jdbc.ResultSetImpl.findColumn(ResultSetImpl.java:1136)
at com.mysql.jdbc.ResultSetImpl.getString(ResultSetImpl.java:5531)
at com.imooc.db.DBUtil.main(DBUtil.java:24)
代码跟老师的一样