title: tdengine’s restful jdbc using alter will have error of invalid variables
body: <p>I used tdengine in mybaits project,and use Taos-jdbc’s restful connector to manipulate the DB. Everything goes will until I used the alter sql try to modify the columns of the table. Then I met an error that is “invalid variables “ the error trace logs are follow:</p>
  <blockquote>
  <p>Caused by: java.sql.SQLException: ERROR (2303): invalid variables at
  com.taosdata.jdbc.TSDBError.createSQLException(TSDBError.java:71) at
  com.taosdata.jdbc.TSDBError.createSQLException(TSDBError.java:58) at
  com.taosdata.jdbc.rs.RestfulStatement.getAffectedRows(RestfulStatement.java:134)
  at
  com.taosdata.jdbc.rs.RestfulStatement.executeOneUpdate(RestfulStatement.java:125)
  at
  com.taosdata.jdbc.rs.RestfulStatement.execute(RestfulStatement.java:82)
  at
  com.taosdata.jdbc.rs.RestfulPreparedStatement.execute(RestfulPreparedStatement.java:218)
  at
  com.zaxxer.hikari.pool.ProxyPreparedStatement.execute(ProxyPreparedStatement.java:44)
  at
  com.zaxxer.hikari.pool.HikariProxyPreparedStatement.execute(HikariProxyPreparedStatement.java)
  at
  org.apache.ibatis.executor.statement.PreparedStatementHandler.update(PreparedStatementHandler.java:47)
  at
  org.apache.ibatis.executor.statement.RoutingStatementHandler.update(RoutingStatementHandler.java:74)
  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at
  sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
  at
  sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
  at java.lang.reflect.Method.invoke(Method.java:498) at
  org.apache.ibatis.plugin.Plugin.invoke(Plugin.java:64) at
  com.sun.proxy.$Proxy211.update(Unknown Source) at
  org.apache.ibatis.executor.SimpleExecutor.doUpdate(SimpleExecutor.java:50)
  at
  org.apache.ibatis.executor.BaseExecutor.update(BaseExecutor.java:117)
  at
  org.apache.ibatis.executor.CachingExecutor.update(CachingExecutor.java:76)
  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at
  sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
  at
  sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
  at java.lang.reflect.Method.invoke(Method.java:498) at
  org.apache.ibatis.plugin.Invocation.proceed(Invocation.java:49) at
  com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor.intercept(MybatisPlusInterceptor.java:106)
  at org.apache.ibatis.plugin.Plugin.invoke(Plugin.java:62) at
  com.sun.proxy.$Proxy210.update(Unknown Source) at
  org.apache.ibatis.session.defaults.DefaultSqlSession.update(DefaultSqlSession.java:194)
  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at
  sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
  at
  sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
  at java.lang.reflect.Method.invoke(Method.java:498) at
  org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:427)
  ... 85 more</p>
  </blockquote>
  <p>However the error was occured but the columns has been add into the table correctly. I don’t know what’s wrong with that,can someone help me?</p>