SQL Server deleted column, error. " Because one or more objects access this column, ALTER TABLE DROP column ... Failed

The teammate gave me the statement to modify the data. Always fails to execute. I wonder. For example:

Look carefully at this column, and there is nothing special. such as:

But it does have a constraint: ' df__his_drug___all_i__04e4bc85 '. Why do we have this constraint???

When I finally searched this article, I understood. Because the column ' All_inventory_state ' is assigned a default value when it is created. That's why we have this constraint.

Reference:

http://blog.csdn.net/rodjohnsondoctor/article/details/7486213

Http://www.ithao123.cn/content-626739.html

=============================================

Reference:

SQL Server deleted column, error. " Because one or more objects access this column, ALTER TABLE DROP column ... Failed