import pymysql
sql = "select id,name,category,price,category1,publish_time from hadoopdata"
def main():
    try:
        db = pymysql.connect(host="localhost",user="root",password="123456",database="pysql")
        cursor = db.cursor()
        cursor.execute(query=sql)
        for user_row in cursor.fetchall():
            id = user_row[0]
            name =user_row[1]
            category = user_row[2]
            price = user_row[3]
            category1 = user_row[4]
            publish_time = user_row[5]
        print("%s %s %s %s %s %s " % (id,name,category,price,category1,publish_time))
    except exception:
        print("error"+traceback.format_exc())
    finally:
        db.close()
if __name__=="__main__":
    main()

#运行结果只显示最后一行第218行的数据，前面的不显示，错在哪里？表在MYSQL里查询此表格是有218条数据的
#218 自粘聚合物改性沥青防水卷材 -218 -218.00 -218 2019-08-01
#进程已结束,退出代码0

问题出在for循环中，循环体内的print语句应该与for循环同级别，即在for循环内部，而不是在循环外部。因为在循环外部，只会输出最后一次循环的结果。

修改后的代码应该是这样的：

import pymysql

sql = "select id,name,category,price,category1,publish_time from hadoopdata"

def main():
    try:
        db = pymysql.connect(host="localhost",user="root",password="123456",database="pysql")
        cursor = db.cursor()
        cursor.execute(query=sql)
        for user_row in cursor.fetchall():
            id = user_row[0]
            name =user_row[1]
            category = user_row[2]
            price = user_row[3]
            category1 = user_row[4]
            publish_time = user_row[5]
            print("%s %s %s %s %s %s " % (id,name,category,price,category1,publish_time))
    except Exception as e:
        print("error: " + str(e))
    finally:
        db.close()

if __name__=="__main__":
    main()

这样就可以输出所有查询结果了。另外，原代码中except exception应该改为except Exception，因为异常类型应该是Exception而不是exception。

谢谢，太感谢了！