检查是否在表上启用了外键

Question

我想在特定表上查看是否启用了外键。那么要检查ms-sql服务器中的表上启用了以下哪个选项？

已启用/禁用，如this：

-- Disable the constraints on a table called tableName:
ALTER TABLE tableName NOCHECK CONSTRAINT ALL

-- Re-enable the constraints on a table called tableName:
ALTER TABLE tableName WITH CHECK CHECK CONSTRAINT ALL
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-- Disable constraints for all tables:
EXEC sp_msforeachtable 'ALTER TABLE ? NOCHECK CONSTRAINT all'

-- Re-enable constraints for all tables:
EXEC sp_msforeachtable 'ALTER TABLE ? WITH CHECK CHECK CONSTRAINT all'
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