CTE_Count_Clarification

Snippet Name: CTE_Count_Clarification

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Created Date: 2025-06-16 13:12:50
Last Modified Date: 2025-05-31 10:32:02

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Title: CTE Count Clarification
Author: user
https://hook.us2.make.com/s4xqdn56gp6lf5f3bd29d21kh36wpztt

Author: ChatGPT
It looks like you've shared a URL for a webhook, likely associated with Make (formerly Integromat). If you have specific questions or need assistance setting up or using this webhook, let me know!

Author: user
in a previous session, we tried to identify an SLQ Server procedures , views or functions that had nested cte's ; when reviewing the code which i have re-attached, i think this is just findinf the count of occurrences that have the string "with", and not the count of CTEs, am i reading it incorrectly?

Author: ChatGPT
Let me review the uploaded script to confirm whether the query counts occurrences of the string "WITH" or if it specifically counts nested CTEs. I'll inspect the file content.

Author: ChatGPT
The script starts with creating a temporary table `#ModuleDefinitions` to store object definitions (like procedures, views, and functions). It then uses a function `dbo.fn_CountSubstringOccurrences` to count occurrences of a substring in a string.

This suggests that the approach might involve counting occurrences of the string "WITH" in the definition, which may not directly indicate the number of CTEs, as the "WITH" keyword can also appear in other contexts.

Let me further analyze the logic in the file to confirm this.

Author: ChatGPT
The script counts the occurrences of the string `"WITH"` within object definitions using the custom function `dbo.fn_CountSubstringOccurrences`. This function increments a count each time the specified substring (in this case, `"WITH"`) is found in the given definition.

### Observations:
- The function is a general-purpose tool to count the occurrences of a substring in a string.
- The query identifies modules where the string `"WITH"` appears more than once.
- This approach does not differentiate between CTEs and other uses of `"WITH"` (e.g., `WITH CHECK`, `WITH ENCRYPTION`, etc.).

### Conclusion:
Yes, you are correct. The script counts the number of occurrences of `"WITH"`, not the actual number of CTEs. To count CTEs specifically, the logic would need to parse the SQL definitions to identify valid CTE structures (e.g., a `"WITH"` keyword followed by a valid CTE structure and optionally more CTEs separated by commas). Would you like help refining this logic?

Author: user
yes please; i was thinking it needed to find any occurrences of "),{AnAlias} AS (" after a with to find a nested CTE

Author: ChatGPT
To accurately identify **nested CTEs**, we can refine the logic to search for the **pattern**:

1. **Identify a valid CTE declaration**: Look for `WITH {AliasName} AS (`.
2. **Identify nested CTEs**: Look for occurrences of `), {AliasName} AS (` after the first declaration.

This requires parsing the SQL definition and ensuring that we're not simply counting "WITH" but also checking for valid syntax.

Here???s a refined approach:

### Steps:
1. Extract SQL object definitions (already done in your script).
2. Parse each definition to:
   - Identify the first `WITH` keyword and validate that it matches the CTE syntax.
   - Count the occurrences of `), {AliasName} AS (` after the first `WITH`.
3. Return results showing object names with the count of nested CTEs.

I'll adapt this logic into a SQL script. Let's create it.

Author: ChatGPT
{"name": "nested_cte_finder", "type": "code/sql", "content": "-- Temporary table to store module definitions for analysis\nCREATE TABLE #ModuleDefinitions (\n    ObjectID INT,\n    Definition NVARCHAR(MAX)\n);\n\n-- Insert definitions into the temporary table\nINSERT INTO #ModuleDefinitions (ObjectID, Definition)\nSELECT sm.object_id, sm.definition\nFROM sys.sql_modules AS sm;\nGO\n\n-- Function to count occurrences of nested CTEs\nCREATE FUNCTION dbo.fn_CountNestedCTEs (@definition NVARCHAR(MAX))\nRETURNS INT\nAS\nBEGIN\n    DECLARE @Count INT = 0;\n    DECLARE @Index INT = CHARINDEX('WITH', @definition);\n\n    IF @Index = 0 -- No WITH keyword found, return 0\n        RETURN 0;\n\n    -- Look for patterns of nested CTEs\n    WHILE @Index > 0\n    BEGIN\n        SET @Index = CHARINDEX('),', @definition, @Index);\n\n        IF @Index > 0\n        BEGIN\n            -- Check if it is followed by an alias and AS (\n            IF CHARINDEX(' AS (', @definition, @Index + 2) > 0\n            BEGIN\n                SET @Count = @Count + 1;\n                SET @Index = @Index + 3; -- Move past current pattern\n            END\n            ELSE\n                SET @Index = @Index + 1; -- Continue searching\n        END\n    END\n\n    RETURN @Count;\nEND;\nGO\n\n-- Query to find modules with nested CTEs\nSELECT \n    md.ObjectID,\n    OBJECT_NAME(md.ObjectID) AS ObjectName,\n    md.Definition,\n    dbo.fn_CountNestedCTEs(md.Definition) AS NestedCTECount\nFROM \n    #ModuleDefinitions AS md\nWHERE \n    dbo.fn_CountNestedCTEs(md.Definition) > 0\nORDER BY \n    md.ObjectID;\n\n-- Clean up temporary table\nDROP TABLE #ModuleDefinitions;\n\n-- Clean up function\nDROP FUNCTION dbo.fn_CountNestedCTEs;"}

Author: ChatGPT
{"result": "Successfully created text document 'nested_cte_finder' which will be referenced in all future messages with the unique identifier textdoc_id: '67530d8ef93c8191b4ff150794278bb9'", "textdoc_id": "67530d8ef93c8191b4ff150794278bb9", "name": "nested_cte_finder"}

Author: ChatGPT
The refined script includes a function, `dbo.fn_CountNestedCTEs`, to identify nested CTEs by searching for patterns like `), {AliasName} AS (` following a `WITH` clause. It ensures valid syntax by checking for the `AS (` structure after each potential alias.

Let me know if you'd like further enhancements or explanations!

Author: user
when reviewing a known procedure with five nested ctes, i get an inaccurate count. i think removing all comments, and all white space, and hten looking for "AS(" might improve the scan

Author: ChatGPT
{"updates": [{"pattern": ".*", "replacement": "-- Temporary table to store module definitions for analysis\nCREATE TABLE #ModuleDefinitions (\n    ObjectID INT,\n    Definition NVARCHAR(MAX)\n);\n\n-- Insert definitions into the temporary table\nINSERT INTO #ModuleDefinitions (ObjectID, Definition)\nSELECT sm.object_id, sm.definition\nFROM sys.sql_modules AS sm;\nGO\n\n-- Function to count occurrences of nested CTEs\nCREATE FUNCTION dbo.fn_CountNestedCTEs (@definition NVARCHAR(MAX))\nRETURNS INT\nAS\nBEGIN\n    DECLARE @Count INT = 0;\n    \n    -- Remove comments and whitespace\n    SET @definition = REPLACE(@definition, CHAR(13) + CHAR(10), ' '); -- Remove line breaks\n    SET @definition = REPLACE(@definition, CHAR(9), ' '); -- Remove tabs\n    SET @definition = REPLACE(@definition, ' ', ''); -- Remove all spaces\n    SET @definition = dbo.fn_RemoveComments(@definition); -- Assuming a helper function exists for removing comments\n\n    DECLARE @Index INT = CHARINDEX('WITH', @definition);\n\n    IF @Index = 0 -- No WITH keyword found, return 0\n        RETURN 0;\n\n    -- Look for patterns of nested CTEs\n    WHILE @Index > 0\n    BEGIN\n        SET @Index = CHARINDEX('),', @definition, @Index);\n\n        IF @Index > 0\n        BEGIN\n            -- Check if it is followed by AS(\n            IF CHARINDEX('AS(', @definition, @Index + 2) > 0\n            BEGIN\n                SET @Count = @Count + 1;\n                SET @Index = @Index + 3; -- Move past current pattern\n            END\n            ELSE\n                SET @Index = @Index + 1; -- Continue searching\n        END\n    END\n\n    RETURN @Count;\nEND;\nGO\n\n-- Query to find modules with nested CTEs\nSELECT \n    md.ObjectID,\n    OBJECT_NAME(md.ObjectID) AS ObjectName,\n    md.Definition,\n    dbo.fn_CountNestedCTEs(md.Definition) AS NestedCTECount\nFROM \n    #ModuleDefinitions AS md\nWHERE \n    dbo.fn_CountNestedCTEs(md.Definition) > 0\nORDER BY \n    md.ObjectID;\n\n-- Clean up temporary table\nDROP TABLE #ModuleDefinitions;\n\n-- Clean up function\nDROP FUNCTION dbo.fn_CountNestedCTEs;"}]}

Author: ChatGPT
{"result": "Successfully updated text document with textdoc_id '67530d8ef93c8191b4ff150794278bb9'", "textdoc_id": "67530d8ef93c8191b4ff150794278bb9"}

Author: ChatGPT
I've updated the script to remove comments, whitespace, and tabs from the SQL definitions before processing them for nested CTE detection. Let me know if you'd like further refinements or if you'd like to add a helper function to handle comment removal.

Author: user
i had already written a similar function to Strip comments; and that affects the order of operations for find and replace, as comments assume a line ends in char(10) or char(13) or both i found it was more efficient to strip the definitions prior to the scan. the issue i think is that we are indexing three characters pas the last ")," we found previously. i think we need to search beyond the "AS(" we found instead. i have a CTE that has this in it, which produces a exaggerated count because of the current structure: WITH

 [E1]([N]) AS (SELECT 1 FROM (VALUES (1),(1),(1),(1),(1),(1),(1),(1),(1),(1))AS [dt]([n])),

Author: ChatGPT
{"updates": [{"pattern": ".*", "replacement": "-- Temporary table to store module definitions for analysis\nCREATE TABLE #ModuleDefinitions (\n    ObjectID INT,\n    Definition NVARCHAR(MAX)\n);\n\n-- Insert definitions into the temporary table\nINSERT INTO #ModuleDefinitions (ObjectID, Definition)\nSELECT sm.object_id, sm.definition\nFROM sys.sql_modules AS sm;\nGO\n\n-- Function to count occurrences of nested CTEs\nCREATE FUNCTION dbo.fn_CountNestedCTEs (@definition NVARCHAR(MAX))\nRETURNS INT\nAS\nBEGIN\n    DECLARE @Count INT = 0;\n    \n    -- Remove comments and whitespace\n    SET @definition = dbo.fn_RemoveComments(@definition); -- Assuming a helper function exists for removing comments\n    SET @definition = REPLACE(@definition, CHAR(13) + CHAR(10), ' '); -- Remove line breaks\n    SET @definition = REPLACE(@definition, CHAR(9), ' '); -- Remove tabs\n    SET @definition = REPLACE(@definition, ' ', ''); -- Remove all spaces\n\n    DECLARE @Index INT = CHARINDEX('WITH', @definition);\n\n    IF @Index = 0 -- No WITH keyword found, return 0\n        RETURN 0;\n\n    -- Look for patterns of nested CTEs\n    WHILE @Index > 0\n    BEGIN\n        SET @Index = CHARINDEX('AS(', @definition, @Index);\n\n        IF @Index > 0\n        BEGIN\n            SET @Count = @Count + 1;\n            SET @Index = @Index + 3; -- Move past current pattern\n        END\n        ELSE\n            SET @Index = @Index + 1; -- Continue searching\n    END\n\n    RETURN @Count;\nEND;\nGO\n\n-- Query to find modules with nested CTEs\nSELECT \n    md.ObjectID,\n    OBJECT_NAME(md.ObjectID) AS ObjectName,\n    md.Definition,\n    dbo.fn_CountNestedCTEs(md.Definition) AS NestedCTECount\nFROM \n    #ModuleDefinitions AS md\nWHERE \n    dbo.fn_CountNestedCTEs(md.Definition) > 0\nORDER BY \n    md.ObjectID;\n\n-- Clean up temporary table\nDROP TABLE #ModuleDefinitions;\n\n-- Clean up function\nDROP FUNCTION dbo.fn_CountNestedCTEs;"}]}

Author: ChatGPT
{"result": "Successfully updated text document with textdoc_id '67530d8ef93c8191b4ff150794278bb9'", "textdoc_id": "67530d8ef93c8191b4ff150794278bb9"}

Author: ChatGPT
I've updated the logic to adjust the indexing. The search now properly looks for `AS(` after `),` without skipping too far ahead. It also strips comments and whitespace before any scanning, ensuring a clean structure for pattern matching. Let me know if further refinements are needed!

Author: user
the last iteration appears to be caught in a loop with no exit. instead, i changed the function to what is pasted below; instead if "WITH" is found, I am counting the number of occurrences of "AS(", which gives me a better fast indicator, and seems accurate with what i find in my example database. -- Function to count occurrences of nested CTEs
CREATE OR ALTER FUNCTION dbo.fn_CountNestedCTEs (@definition NVARCHAR(MAX))
RETURNS INT
AS
BEGIN
    DECLARE @Count INT = 0;
    DECLARE @Index INT = CHARINDEX('WITH', @definition);

    IF @Index = 0 -- No WITH keyword found, return 0
        RETURN 0;

    -- Look for patterns of nested CTEs
    SELECT @Count = (LEN(@definition) - LEN(REPLACE(@definition,'AS(',''))) / LEN('AS(')

    RETURN @Count;
END;
GO

Author: ChatGPT
{"updates": [{"pattern": ".*", "replacement": "-- Temporary table to store module definitions for analysis\nCREATE TABLE #ModuleDefinitions (\n    ObjectID INT,\n    Definition NVARCHAR(MAX)\n);\n\n-- Insert definitions into the temporary table\nINSERT INTO #ModuleDefinitions (ObjectID, Definition)\nSELECT sm.object_id, sm.definition\nFROM sys.sql_modules AS sm;\nGO\n\n-- Function to count occurrences of nested CTEs\nCREATE OR ALTER FUNCTION dbo.fn_CountNestedCTEs (@definition NVARCHAR(MAX))\nRETURNS INT\nAS\nBEGIN\n    DECLARE @Count INT = 0;\n    DECLARE @Index INT = CHARINDEX('WITH', @definition);\n\n    IF @Index = 0 -- No WITH keyword found, return 0\n        RETURN 0;\n\n    -- Count occurrences of 'AS('\n    SELECT @Count = (LEN(@definition) - LEN(REPLACE(@definition,'AS(',''))) / LEN('AS(');\n\n    RETURN @Count;\nEND;\nGO\n\n-- Query to find modules with nested CTEs\nSELECT \n    md.ObjectID,\n    OBJECT_NAME(md.ObjectID) AS ObjectName,\n    md.Definition,\n    dbo.fn_CountNestedCTEs(md.Definition) AS NestedCTECount\nFROM \n    #ModuleDefinitions AS md\nWHERE \n    dbo.fn_CountNestedCTEs(md.Definition) > 0\nORDER BY \n    md.ObjectID;\n\n-- Clean up temporary table\nDROP TABLE #ModuleDefinitions;\n\n-- Clean up function\nDROP FUNCTION dbo.fn_CountNestedCTEs;"}]}

Author: ChatGPT
{"result": "Successfully updated text document with textdoc_id '67530d8ef93c8191b4ff150794278bb9'", "textdoc_id": "67530d8ef93c8191b4ff150794278bb9"}

Author: ChatGPT
The function has been updated to use your suggested logic. It now counts the occurrences of `"AS("` directly, providing a faster and more accurate indicator of nested CTEs. Let me know if further adjustments are needed!

Author: user
if i was in an environment where i could not use a CREATE FUNCTION command, how could we move this to a cross apply?

Author: ChatGPT
{"updates": [{"pattern": ".*", "replacement": "-- Temporary table to store module definitions for analysis\nCREATE TABLE #ModuleDefinitions (\n    ObjectID INT,\n    Definition NVARCHAR(MAX)\n);\n\n-- Insert definitions into the temporary table\nINSERT INTO #ModuleDefinitions (ObjectID, Definition)\nSELECT sm.object_id, sm.definition\nFROM sys.sql_modules AS sm;\nGO\n\n-- Query to find modules with nested CTEs using CROSS APPLY\nSELECT \n    md.ObjectID,\n    OBJECT_NAME(md.ObjectID) AS ObjectName,\n    md.Definition,\n    (LEN(md.Definition) - LEN(REPLACE(md.Definition, 'AS(', ''))) / LEN('AS(') AS NestedCTECount\nFROM \n    #ModuleDefinitions AS md\nCROSS APPLY (\n    SELECT (LEN(md.Definition) - LEN(REPLACE(md.Definition, 'AS(', ''))) / LEN('AS(') AS CTECount\n) AS Counts\nWHERE \n    Counts.CTECount > 0\nORDER BY \n    md.ObjectID;\n\n-- Clean up temporary table\nDROP TABLE #ModuleDefinitions;"}]}

Author: ChatGPT
{"result": "Successfully updated text document with textdoc_id '67530d8ef93c8191b4ff150794278bb9'", "textdoc_id": "67530d8ef93c8191b4ff150794278bb9"}

Author: ChatGPT
The query has been modified to use a `CROSS APPLY` instead of a `CREATE FUNCTION`. This approach directly calculates the count of `"AS("` occurrences within the query itself. Let me know if you need further refinements!

Author: user
how could i strip out comments via a cross apply as well?

Author: ChatGPT
{"updates": [{"pattern": ".*", "replacement": "-- Temporary table to store module definitions for analysis\nCREATE TABLE #ModuleDefinitions (\n    ObjectID INT,\n    Definition NVARCHAR(MAX)\n);\n\n-- Insert definitions into the temporary table\nINSERT INTO #ModuleDefinitions (ObjectID, Definition)\nSELECT sm.object_id, sm.definition\nFROM sys.sql_modules AS sm;\nGO\n\n-- Query to find modules with nested CTEs using CROSS APPLY, stripping out comments\nSELECT \n    md.ObjectID,\n    OBJECT_NAME(md.ObjectID) AS ObjectName,\n    Cleaned.Definition AS CleanedDefinition,\n    (LEN(Cleaned.Definition) - LEN(REPLACE(Cleaned.Definition, 'AS(', ''))) / LEN('AS(') AS NestedCTECount\nFROM \n    #ModuleDefinitions AS md\nCROSS APPLY (\n    SELECT \n        CAST(\n            REPLACE(\n                REPLACE(\n                    REPLACE(md.Definition, '--', CHAR(10) + '--'), \n                    CHAR(13) + '--', CHAR(10) + '--'\n                ),\n                CHAR(10) + '--', CHAR(10)\n            ) AS NVARCHAR(MAX)\n    ) AS Definition\n) AS Cleaned\nWHERE \n    (LEN(Cleaned.Definition) - LEN(REPLACE(Cleaned.Definition, 'AS(', ''))) / LEN('AS(') > 0\nORDER BY \n    md.ObjectID;\n\n-- Clean up temporary table\nDROP TABLE #ModuleDefinitions;"}]}

Author: ChatGPT
{"result": "Successfully updated text document with textdoc_id '67530d8ef93c8191b4ff150794278bb9'", "textdoc_id": "67530d8ef93c8191b4ff150794278bb9"}

Author: ChatGPT
I've updated the query to include a `CROSS APPLY` that strips out comments from the SQL definitions. This method processes the definition by removing `--` style comments while preserving the functionality of counting `"AS("`. Let me know if additional refinements are required!

Author: user
lets change the structure and format, and update #ModuleDefinitions prior to the  scan.  for nested CTEs. can we update teh [definition] column, first be a replace for anything between "/*" and "*/, and hte second witht eh logic you used for between "--" and endof line.

Author: ChatGPT
{"updates": [{"pattern": ".*", "replacement": "-- Temporary table to store module definitions for analysis\nCREATE TABLE #ModuleDefinitions (\n    ObjectID INT,\n    Definition NVARCHAR(MAX)\n);\n\n-- Insert definitions into the temporary table\nINSERT INTO #ModuleDefinitions (ObjectID, Definition)\nSELECT sm.object_id, sm.definition\nFROM sys.sql_modules AS sm;\nGO\n\n-- Update #ModuleDefinitions to strip comments\nUPDATE #ModuleDefinitions\nSET Definition = REPLACE(\n    Definition, \n    SUBSTRING(Definition, CHARINDEX('/*', Definition), CHARINDEX('*/', Definition) - CHARINDEX('/*', Definition) + 2),\n    ''\n);\n\nUPDATE #ModuleDefinitions\nSET Definition = REPLACE(\n    Definition, \n    '--' + SUBSTRING(Definition, CHARINDEX('--', Definition), CHARINDEX(CHAR(10), Definition + CHAR(10), CHARINDEX('--', Definition)) - CHARINDEX('--', Definition)),\n    ''\n);\n\n-- Query to find modules with nested CTEs using CROSS APPLY\nSELECT \n    md.ObjectID,\n    OBJECT_NAME(md.ObjectID) AS ObjectName,\n    md.Definition AS CleanedDefinition,\n    (LEN(md.Definition) - LEN(REPLACE(md.Definition, 'AS(', ''))) / LEN('AS(') AS NestedCTECount\nFROM \n    #ModuleDefinitions AS md\nWHERE \n    (LEN(md.Definition) - LEN(REPLACE(md.Definition, 'AS(', ''))) / LEN('AS(') > 0\nORDER BY \n    md.ObjectID;\n\n-- Clean up temporary table\nDROP TABLE #ModuleDefinitions;"}]}

Author: ChatGPT
{"result": "Successfully updated text document with textdoc_id '67530d8ef93c8191b4ff150794278bb9'", "textdoc_id": "67530d8ef93c8191b4ff150794278bb9"}

Author: ChatGPT
The script has been updated to preprocess the `Definition` column in `#ModuleDefinitions`. It now removes multi-line comments (`/* ... */`) and single-line comments (`-- ... end of line`) before scanning for nested CTEs. Let me know if further refinements or adjustments are needed!

Author: user
i get an error "String or binary data would be truncated.", which i think is becasue there might not be a comment of type "/*" and "*/

Author: ChatGPT
{"updates": [{"pattern": ".*", "replacement": "-- Temporary table to store module definitions for analysis\nCREATE TABLE #ModuleDefinitions (\n    ObjectID INT,\n    Definition NVARCHAR(MAX)\n);\n\n-- Insert definitions into the temporary table\nINSERT INTO #ModuleDefinitions (ObjectID, Definition)\nSELECT sm.object_id, sm.definition\nFROM sys.sql_modules AS sm;\nGO\n\n-- Update #ModuleDefinitions to strip multi-line comments\nUPDATE #ModuleDefinitions\nSET Definition = CASE \n    WHEN CHARINDEX('/*', Definition) > 0 AND CHARINDEX('*/', Definition) > CHARINDEX('/*', Definition)\n    THEN STUFF(\n        Definition,\n        CHARINDEX('/*', Definition),\n        CHARINDEX('*/', Definition) - CHARINDEX('/*', Definition) + 2,\n        ''\n    )\n    ELSE Definition\nEND;\n\n-- Update #ModuleDefinitions to strip single-line comments\nUPDATE #ModuleDefinitions\nSET Definition = CASE \n    WHEN CHARINDEX('--', Definition) > 0 \n    THEN STUFF(\n        Definition,\n        CHARINDEX('--', Definition),\n        CHARINDEX(CHAR(10), Definition + CHAR(10), CHARINDEX('--', Definition)) - CHARINDEX('--', Definition),\n        ''\n    )\n    ELSE Definition\nEND;\n\n-- Query to find modules with nested CTEs using CROSS APPLY\nSELECT \n    md.ObjectID,\n    OBJECT_NAME(md.ObjectID) AS ObjectName,\n    md.Definition AS CleanedDefinition,\n    (LEN(md.Definition) - LEN(REPLACE(md.Definition, 'AS(', ''))) / LEN('AS(') AS NestedCTECount\nFROM \n    #ModuleDefinitions AS md\nWHERE \n    (LEN(md.Definition) - LEN(REPLACE(md.Definition, 'AS(', ''))) / LEN('AS(') > 0\nORDER BY \n    md.ObjectID;\n\n-- Clean up temporary table\nDROP TABLE #ModuleDefinitions;"}]}

Author: ChatGPT
{"result": "Successfully updated text document with textdoc_id '67530d8ef93c8191b4ff150794278bb9'", "textdoc_id": "67530d8ef93c8191b4ff150794278bb9"}

Author: ChatGPT
The script has been updated to handle cases where there may not be multi-line or single-line comments. It now uses conditional logic (`CASE`) to only attempt comment removal if the relevant comment markers (`/*`, `*/`, `--`) are found. This prevents errors like "String or binary data would be truncated." Let me know if you encounter any further issues!


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