Let's ask a thinkphp about the save question.

If I want to implement the Update table set a=a-1 where a>=1 such sql

How did you write it with thinkphp? SAVE?

Reply to discussion (solution)

Update
Update ($DATA, $options)

Update
Update ($DATA, $options)

Well, I see in the bottom class, there is a way to change the value of the update to the type of the database definition, the above A-1 is a string, the intval is converted to 0.

Thinkphp have this kind of things, but not very perfect, look at the manual will be able to find Setdec

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