Tiktok actual battle ~ take off the blogger

One 、 Demand analysis

1. Take off flow chart

2. Brief description of customs clearance process

• 1. The front-end carries users ID And short video publishers ID Request back-end access interface
• 2. Judge whether we are friends
  • 2.1. Non friend relationship , Delete your own related table records
  • 2.2. Friendship , Erase the friendship between the two sides , Set non friend status , Update the database
• 3. I focus on total -1（redis）
• 4. The number of bloggers' fans -1（redis）
• 5. Delete my relationship with the short video blogger （redis）

Two 、 Source code combat

2.1. Take off ~ front end

//  Cancel the attention 
			cancelFollow(vlogerId) {
    
				var me = this;
				var userId = getApp().getUserInfoSession().id;
				var serverUrl = app.globalData.serverUrl;
				uni.request({
    
					method: "POST",
					header: {
    
						headerUserId: userId,
						headerUserToken: app.getUserSessionToken()
					},
					url: serverUrl + "/fans/cancel?myId=" + userId + "&vlogerId=" + vlogerId,
					success(result) {
    
						
						if (result.data.status == 200) {
    
							me.reFreshList(vlogerId, false);
						} else {
    
							uni.showToast({
    
								title: result.data.msg,
								icon: "none",
								duration: 3000
							});
						}
					}
				});
				
			},

2.2. Take off ~ Back end

/**
     *  Take off 
     *
     * @param myId      My users ID
     * @param vlogerId  Video publisher ID
     * @return
     */
    @PostMapping("cancel")
    public GraceJSONResult cancel(@RequestParam String myId,
                                  @RequestParam String vlogerId) {
    

        //  Delete the execution of the business 
        fansService.doCancel(myId, vlogerId);

        //  Blogger fans -1, My attention -1
        // My total number of concerns 
        redis.decrement(REDIS_MY_FOLLOWS_COUNTS + ":" + myId, 1);
        //  The total number of bloggers' fans 
        redis.decrement(REDIS_MY_FANS_COUNTS + ":" + vlogerId, 1);

        //  My relationship with bloggers , rely on redis, Do not store databases , avoid db Performance bottlenecks 
        redis.del(REDIS_FANS_AND_VLOGGER_RELATIONSHIP + ":" + myId + ":" + vlogerId);

        return GraceJSONResult.ok();
    }

/** *  Take off  * * @param myId  My users ID * @param vlogerId  Video publisher ID * @return */
    @Transactional
    @Override
    public void doCancel(String myId, String vlogerId) {
    

        //  Judge whether we are friends , If it is , You need to cancel the relationship between the two sides 
        Fans fan = queryFansRelationship(myId, vlogerId);
        if (fan != null && fan.getIsFanFriendOfMine() == YesOrNo.YES.type) {
    
            //  Erase the friendship between the two sides , Delete your own relationship 
            Fans pendingFan = queryFansRelationship(vlogerId, myId);
            pendingFan.setIsFanFriendOfMine(YesOrNo.NO.type);
            fansMapper.updateByPrimaryKeySelective(pendingFan);
        }

        //  Delete your own related table records 
        fansMapper.delete(fan);
    }

3、 ... and 、5217 Actual combat of customs clearance

3.1. Data analysis before customs clearance

Tail number ~0009
Focus on ：1
fans ：2

Tail number ~5217
Focus on ：3
fans ：2

3.2. account number 5217 Take off

Tail number ~0009
Focus on ：1
fans ：1 -> from 2 Turned into 1

Tail number ~5217
Focus on ：2 -> from 3 Turned into 2
fans ：2

The piece of data I am concerned about has been deleted , Blogger and I are not friends anymore

Four 、 account number 0009 Actual combat of customs clearance

4.1. account number 0009 Take off

Tail number ~0009
Focus on ：0 from 1 Turned into 0
fans ：1

Tail number ~5217
Focus on ：2 -> from 3 Turned into 2
fans ：1 -> from 2 Turned into 1

4.2. Data changes

0009 The information about the account has also been deleted