Question

我有两张桌子：

reports:
    date, uuid
warns:
    date, uuid, active

date是时间戳（2016-05-16 16:06:58），uuid是用户标识符字符串，active是布尔值。

我想显示每天有多少reports和warns条目。目前我有这个问题：

SELECT DATE(date) Date, count(*) Reports
FROM reports
GROUP BY DATE(date)
ORDER BY DATE(date) DESC

显示如下表格：

Date       | Reports 
-----------+---------
2016-07-05 | 192     
2016-07-04 | 230     
2016-07-03 | 227

但我也希望加入当天发生的warns个条目数，但前提是它的active列是TRUE，所以我希望查询返回像这样的表：

Date       | Reports | Warns
-----------+---------+-------
2016-07-05 | 192     | 47
2016-07-04 | 230     | 59
2016-07-03 | 227     | 56

我是MYSQL的新手，所以我还没有弄清楚我会怎么做。我在JOINS和UNIONS上搜索了一下但是不知道它们是否适用于我的案例。任何帮助将不胜感激。

Answer 1

您可以使用相关查询：

SELECT DATE(reports.date) Date, count(*) Reports,
       (SELECT COUNT(*) FROM warns
        WHERE DATE(warns.date) = DATE(reports.date) and warns.active = 'TRUE') as warns_cnt
FROM reports
GROUP BY DATE(reports.date)
ORDER BY DATE(reports.date) DESC

Answer 2

为了说明联盟你可以： -

float moveSpeed = 3f;
float rotationSpeed = 3f;
float attackThreshold = 3f;   //distance within which to attack
float chaseThreshold = 10f;   //distance within which to start chasing
float giveUpThreshold = 20f;  //distance beyond which AI gives up
float attackRepeatTime = 1f;  //time between attacks
bool attacking = false;
bool chasing = false;
float attackTime;
Transform target;             //the enemy's target
Transform myTransform;        //current transform data of the enemy

void Update()
{
     //rotate to look at the player
     float distance = (target.position - myTransform.position).magnitude;
     if (chasing)
     {
         myTransform.rotation = Quaternion.Slerp(myTransform.rotation, Quaternion.LookRotation(target.position - myTransform.position), rotationSpeed * Time.deltaTime);
     }

     //move towards the player
     if (chasing == true && attacking == false)
         myTransform.position += myTransform.forward * moveSpeed * Time.deltaTime;

     //give up if too far away
     if (distance >= giveUpThreshold)
     {
         chasing = false;
     //    attacking = false;
     }

     //attack, if close enough, and if time is OK
     if (distance <= attackThreshold && Time.time >= attackTime) //if attacking we want to stop moving
     {
         //attack here
         bossAttack.Attack();
         attackTime = Time.time + attackRepeatTime;
         print("Attacking!");
         attacking = true;
       //  anim.SetTrigger("AutoAttack");
         chasing = false;
     }
     else
     {
         //not currently chasing.
         //start chasing if target comes close enough
         if (distance <= chaseThreshold)  //if he gets to chase, and then you move out of range again, he won't chase again. he will only attack if comes into range again
         {
             chasing = true;
           //  attacking = false;
             //   print("Chasing!");
         }
     }
 }

查询在子查询中创建REPORTS和WARNS列，然后在子查询外部进行求和。

每天计算来自不同表的条目

2 个答案: