truncated operation的意思|示意

If the operation occurs in an unchecked context, the result is truncated by discarding any high-order bits that do not fit into the destination type.

如果操作发生在未检查的上下文中，计算的结果被截断，放弃不适合目标类型的任何高序位。

Additionally, there cannot be a foreign key constraint between the table being truncated and other tables, otherwise the truncate table operation fails.

此外，被truncate的表和其他表之间是不能有外键约束的，否则truncate TABLE操作会失败。