Foreign keys of a table (or foreign references)

In MSSQL, at some point, you might need to find the foreign keys of a table.

Below mydb and mytable are placeholders.

You can test this with a table having foreign key but I ‘d like to approach the query as if there is no foreign key in the table.

If the first query results with no column name as header and 9 digit numeric number, that confirms the database and table exists,

and if the rest queries are giving empty results, then there is no foreign key.

USE mydb
SELECT object_id('mytable')

SELECT
  object_name(parent_object_id) ParentTableName,
  object_name(referenced_object_id) RefTableName,
  name 
FROM sys.foreign_keys

select
    PKTABLE_QUALIFIER   = convert(sysname,db_name()),
    PKTABLE_OWNER       = convert(sysname,schema_name(o1.schema_id)),
    PKTABLE_NAME        = convert(sysname,o1.name),
    PKCOLUMN_NAME       = convert(sysname,c1.name),
    FKTABLE_QUALIFIER   = convert(sysname,db_name()),
    FKTABLE_OWNER       = convert(sysname,schema_name(o2.schema_id)),
    FKTABLE_NAME        = convert(sysname,o2.name),
    FKCOLUMN_NAME       = convert(sysname,c2.name),
    -- Force the column to be non-nullable (see SQL BU 325751)
    KEY_SEQ             = isnull(convert(smallint,k.constraint_column_id), 0),
    UPDATE_RULE         = convert(smallint,
                                    case f.update_referential_action
                                    when 1 then 0
                                    when 0 then 1
                                    else f.update_referential_action
                                    end),
    DELETE_RULE         = convert(smallint,
                                    case f.delete_referential_action
                                    when 1 then 0
                                    when 0 then 1
                                    else f.delete_referential_action
                                    end),
    FK_NAME             = convert(sysname,object_name(f.object_id)),
    PK_NAME             = convert(sysname,i.name),
    DEFERRABILITY       = convert(smallint, 7)   -- SQL_NOT_DEFERRABLE
from
    sys.objects o1,
    sys.objects o2,
    sys.columns c1,
    sys.columns c2,
    sys.foreign_keys f inner join
    sys.foreign_key_columns k on (k.constraint_object_id = f.object_id) inner join
    sys.indexes i on (f.referenced_object_id = i.object_id and f.key_index_id = i.index_id)
where
    o1.object_id = f.referenced_object_id and
    (o1.object_id =  object_id('dbo.mytable')) and
    o2.object_id = f.parent_object_id and
    c1.object_id = f.referenced_object_id and
    c2.object_id = f.parent_object_id and
    c1.column_id = k.referenced_column_id and
    c2.column_id = k.parent_column_id
order by 5, 6, 7, 9, 8