You have an error in your SQL syntax

Exception in thread "main" 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 'str' at line 1
 at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
 at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
 at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
 at java.lang.reflect.Constructor.newInstance(Unknown Source)
 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:3515)
 at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3447)
 at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1951)
 at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2101)
 at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2548)
 at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2477)
 at com.mysql.jdbc.StatementImpl.executeQuery(StatementImpl.java:1422)
 at test.JDBCTest.main(JDBCTest.java:15)

 

 

ResultSet找不到指定的列