select-mysql按月分组,取每月日期小的

DROP TABLE IF EXISTS t_test;

/*!40101 SET @saved_cs_client = @@character_set_client /;
/!40101 SET character_set_client = utf8 /;
CREATE TABLE t_test (
id int(11) NOT NULL AUTO_INCREMENT,
org varchar(10) DEFAULT NULL,
status date DEFAULT NULL,
PRIMARY KEY (id)
) ENGINE=InnoDB AUTO_INCREMENT=13 DEFAULT CHARSET=utf8;
/!40101 SET character_set_client = @saved_cs_client */;

-- Dumping data for table t_test

LOCK TABLES t_test WRITE;
/*!40000 ALTER TABLE t_test DISABLE KEYS /;
INSERT INTO t_test VALUES (1,'qwe','2015-02-09'),(2,'qqq','2015-03-03'),(3,'www','2012-02-11'),(4,'qwe','2015-03-10'),(5,'asd','2015-04-10'),(6,'fff','2015-05-10'),(7,'aaa','2015-10-10'),(8,'fff','2015-03-10'),(9,'www','2012-02-01'),(10,'asd','2015-03-02'),(11,'qwe','2015-03-26'),(12,'www','2012-03-11');
/!40000 ALTER TABLE t_test ENABLE KEYS */;
UNLOCK TABLES;

上面是表里面测试数据，按照月份分组，取每个月日期最小的数据