sp_Blitz: include affected foreign key count in “Foreign Keys Not Trusted” details

[Copilot]

The sp_Blitz “Foreign Keys Not Trusted” finding (CheckID 48) currently reports only that a database has untrusted foreign keys. This update makes the details message include the number of affected foreign keys in that database.

• What changed

  • Updated the CheckID 48 query in sp_Blitz.sql to compute and inject the FK count into Details.
  • Replaced the non-counted wording:
    • The [X] database has foreign keys that were...
    • with:
    • The [X] database has Y foreign keys that were...

• Query shape adjustment for counted output

  • Switched from SELECT DISTINCT 48 to an aggregate SELECT 48 with COUNT(*).
  • Added HAVING COUNT(*) > 0 so rows are emitted only when untrusted FKs exist.

• Scope

  • Only sp_Blitz.sql was modified.
  • Install%.sql scripts were intentionally not edited.

(''The ['' + DB_NAME() + ''] database has '' + CAST(COUNT(*) AS NVARCHAR(20)) 
 + '' foreign keys that were probably disabled, data was changed, and then the key was enabled again...'')

[BrentOzar]

Doesn't this query now need a group by since it's got a HAVING and a SUM?

[Copilot]

Doesn't this query now need a group by since it's got a HAVING and a SUM?

Good catch to ask. In this case, no GROUP BY is required in SQL Server because the query is a single aggregate group (COUNT(*)) with no grouped columns, and HAVING COUNT(*) > 0 is valid on that implicit group. Also, it’s COUNT(*) (not SUM) in commit 9fad54c.

[BrentOzar]

Looks good! Thanks, Captain Circuits.

[Copilot]

Pull request overview

Updates sp_Blitz CheckID 48 (“Foreign Keys Not Trusted”) to include the number of untrusted foreign keys in the Details message for each affected database.

Changes:

• Switched CheckID 48 output to an aggregate query so it can compute COUNT(*) of untrusted foreign keys.
• Injected the computed FK count into the Details string.
• Added HAVING COUNT(*) > 0 to avoid emitting a row when no untrusted foreign keys exist.

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[Copilot]

The updated Details string will produce grammatically incorrect output when exactly 1 foreign key is affected ("1 foreign keys"). Consider adding singular/plural handling so the message reads correctly for both 1 and >1.

Suggested change

(''The ['' + DB_NAME() + ''] database has '' + CAST(COUNT(*) AS NVARCHAR(20)) + '' foreign keys that were probably disabled, data was changed, and then the key was enabled again. Simply enabling the key is not enough for the optimizer to use this key - we have to alter the table using the WITH CHECK CHECK CONSTRAINT parameter.'')

(''The ['' + DB_NAME() + ''] database has '' + CAST(COUNT(*) AS NVARCHAR(20)) + CASE WHEN COUNT(*) = 1 THEN '' foreign key that was probably disabled, data was changed, and then the key was enabled again. Simply enabling the key is not enough for the optimizer to use this key - we have to alter the table using the WITH CHECK CHECK CONSTRAINT parameter.'' ELSE '' foreign keys that were probably disabled, data was changed, and then the key was enabled again. Simply enabling the key is not enough for the optimizer to use this key - we have to alter the table using the WITH CHECK CHECK CONSTRAINT parameter.'' END)

[Copilot]

Now that this check aggregates to a single row, the joins to sys.objects and sys.schemas are no longer used for filtering or output. Consider removing the joins and counting directly from sys.foreign_keys to reduce query work and keep the check simpler.

Suggested change

	from [?].sys.foreign_keys i INNER JOIN [?].sys.objects o ON i.parent_object_id = o.object_id INNER JOIN [?].sys.schemas s ON o.schema_id = s.schema_id
	from [?].sys.foreign_keys i