查询构造器

QueryBuilder是一个SQL构造器，用来构造prepare sql。例如：

use EasySwoole\Mysqli\QueryBuilder;

$builder = new QueryBuilder();

//执行条件构造逻辑
$builder->where('col1',2)->get('my_table');

//获取最后的查询参数
echo $builder->getLastQueryOptions();

//获取子查询
echo $builder->getSubQuery();

//获取上次条件构造的预处理sql语句
echo $builder->getLastPrepareQuery();
// SELECT  * FROM whereGet WHERE  col1 = ? 

//获取上次条件构造的预处理sql语句所以需要的绑定参数
echo $builder->getLastBindParams();
//[2]

//获取上次条件构造的sql语句
echo $builder->getLastQuery();
//SELECT  * FROM whereGet WHERE  col1 = 2 

// 获取最后插入的insert_id 使用客户端从swoole mysql获取
$client->mysqlClient()->insert_id