如何根据 MySQL 中的当前值更新字段? [英] How to update a field based on its current value in MySQL?

问题描述

是否可以获取某个字段的当前值，将其用作计算中的变量，然后根据结果更新该字段?

Is it possible to get the current value of a field, use it as a variable in a calculation, then update the field based on the result?

例如table1中ID为1"的记录的值为2"

For example the record with the ID "1" in table1 has a value of "2"

SELECT table1
WHERE ID = "1"
SET RESULT to CurrentID
RESULT = CurrentID + 1;

推荐答案

这会将 result 列设置为 CurrentID 列的值(加 1)同一行，对于任何 ID 列等于1"的行:

This will set the result column to the value of the CurrentID column (plus 1) of the same row, for any row that has an ID column that equals "1":

UPDATE table1
SET result = CurrentID + 1
WHERE ID = "1"

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