from是SQL中的关键字.如果不引用，则不能将其用作列名.在MySQL中，列名之类的内容用反引号引起来，即`from`.

from is a keyword in SQL. You may not used it as a column name without quoting it. In MySQL, things like column names are quoted using backticks, i.e. `from`.

我个人不会打扰；我只是重命名该列.

Personally, I wouldn't bother; I'd just rename the column.

PS.如注释中所指出的，to是另一个SQL关键字，因此也需要将其引起来.方便地，drupal.org上的人员维护一个列表SQL中的保留字.

PS. as pointed out in the comments, to is another SQL keyword so it needs to be quoted, too. Conveniently, the folks at drupal.org maintain a list of reserved words in SQL.