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连续聚合是按时间顺序对有序数据进行聚合的操作。
CREATE TABLE EmpOrders (empid INT NOT NULL,ordermonth DATE NOT NULL,qty INT NOT NULL,testPRIMARY KEY (empid,ordermonth));
INSERT INTO EmpOrders SELECT a.employeeid,orderdate AS Order date,SUM(quantity) AS qty FROM orders aINNER JOIN orderdetails bON a.orderid=b.orderidGROUP BY employid,DATE_FORMAT(orderdate,'%Y-m');
下面给出生成示例数据的php文件
';$insert_sql = '';for($empid=1;$empid<=8;$empid++){ for($year=2009;$year<=2015;$year++) { for($month=1;$month<=12;$month++) { $num = rand(20,800); $insert_sql .= sprintf($sql,$empid,$year,$month,$num); } $insert_sql .= ''; }}echo $insert_sql; 转载地址：http://wclkz.baihongyu.com/