Learning video: https://www.bilibili.com/video/av49181542?p=100
Network disk resources: https://pan.baidu.com/s/1fU5crRmv-sJUJq9fDAUuxw Extraction code: 2vpn
Shang Silicon Valley official website: http:/ /www.atguigu.com/download.shtml#JavaSE
equijoin and natural join
outer join: