Long integer variables are stored as 32-bit (4 bytes) signed values ranging from -2,147,483,648 to 2,147,483,647. The type declaration character of Long is ampersand; )。
2. If the automatic numbering starts from 1, once it reaches 2 147483647, it will automatically jump to -2 147483648, and then continue to shrink until 0.
3. If 1 is reached again, if the "Index" attribute of the automatic numbering field is defined as "Yes (no duplicate)" when designing the table, the system will prompt an error. If it is not set, the automatic numbering will continue to increase from 1.