I came a situation during some analysis where i had to figure out all dependency of a column across database. This also required when we do some changes on table columns and wanted to know the impact of such changes. One way is that we can use SYSCOMMENTS table. It is a table which contains entries for each views, rules, default, trigger, CHECK constraint, DEFAULT constraint, and stored procedure. The column TEXT in the syscomments table contains the actual code for all these objects, and knowing it you can write a code to check the dependencies. I am explaining different approach.
/* Table Name for which we need to find the dependency of columns.*/
Declare @TableNamevarchar(max)='tblSupplierRequestOrder'
/* Column name for which we need to find the dependnecy in a database*/
Declare @ColumnNamevarchar(max)='OrderDate'
select OBJECT_NAME(k.parent_object_id) as parentTableName
, c1.name as parentColumn
, OBJECT_NAME(k.referenced_object_id)as referencedTableName
, c2.name as referencedColumn
from sys.foreign_keys k
innerjoin sys.foreign_key_columnsf
on f.parent_object_id = k.parent_object_id
innerjoin sys.columns c1
on c1.column_id = f.parent_column_id
andc1.object_id = k.parent_object_id
innerjoin sys.columns c2
on c2.column_id = f.referenced_column_id
andc2.object_id = k.referenced_object_id
where c2.name = @ColumnName
and OBJECT_NAME(k.referenced_object_id)=@TableName
