如何查找外键引用表上的索引

Question

我有一个非聚集索引我想删除(它是聚集索引的副本).但是,它正由外键约束使用.我希望能够确定哪个约束正在使用索引,因此我可以更新它以使用主键索引.

当我试图放弃它时:

DROP INDEX [idx_duplicate] ON [dbo].[MyTable]

我收到一个错误:

索引'dbo.MyTable.idx_duplicate'上不允许显式DROP INDEX.它用于FOREIGN KEY约束实施.

我试图通过以下查询找到罪魁祸首,但没有运气:

SELECT name
FROM sys.foreign_keys
WHERE OBJECT_NAME (referenced_object_id) = 'idx_duplicate'

Answer 1

就像是

Select
    f.name,
    object_name(f.parent_object_id)
From
    sys.foreign_keys f
        inner join
    sys.indexes i
        on f.referenced_object_id = i.object_id and
           f.key_index_id = i.index_id
Where
    i.name = 'idx_duplicate' and
    i.object_id = object_id('[dbo].[MyTable]')

Answer 2

这将告诉您表,外键和涉及的列:

select f.name
  , parentTable = o.name
  , parentColumn = c.name
  , foreignTable = ofr.name
  , foreignColumn = cfr.name
from sys.foreign_keys f
  inner join sys.foreign_key_columns fc on f.object_id = fc.constraint_object_id
  inner join sys.objects o on fc.parent_object_id = o.object_id
  inner join sys.columns c on fc.parent_column_id = c.column_id
    and o.object_id = c.object_id
  inner join sys.objects ofr on fc.referenced_object_id = ofr.object_id
  inner join sys.columns cfr on fc.referenced_column_id = cfr.column_id
    and ofr.object_id = cfr.object_id
  inner join sys.indexes i on ofr.object_id = i.object_id
where i.name = 'MyIndex'

SQL小提琴演示.