我需要使用插入或内部连接吗？

Question

我正在使用MySQL版本5.我有两个表格，如下所示。

表1

From     To     Time     TravelTime

表2

From    To      Time     CongestionTime

我想实现以下输出。

如果两个表格中From，To和Time相等，则分配TravelTime = CongestionTime

Table2 仅包含 Table1 中可用的From | To | Time组合的子集。

Answer 1

From是mysql保留字。如果您不想转义它，请将列名“From”更改为“TimeFrom”。

UPDATE table1,table2
SET table1.TravelTime=table2.CongestionTime
WHERE table1.From = table2.From
AND table1.To = table2.To

Answer 2

Update Table1 Set Table1.TravelTime = Table2.CongestionTime
FROM Table2
WHERE Table1.From = Table2.From
      AND Table1.To = Table2.To
      AND Table1.Time = Table2.Time

Answer 3

update table1
set traveltime = congestiontime
from table1
inner join table2 on table1.from = table2.from 
and table1.to = table2.to 
and table1.time = table2.time