mssql_script: allow non-returning SQL statements (#6457)

* feat: Allow non-returning SQL statements

- The current implementation fails out when certain statements or
  batches do not have resultsets - this limits the usefulness of the
  module
- Instead, it is known that statements without resultsets return then
  OperationalError exception with text "Statement not executed or
  executed statement has no resultset". We will utilize these facts to
  accept these statements
- The implementation also assumes that users will always use best-
  practices for the script syntax; that is, "GO" will always be
  capitalized but this is not strictly required -- update to allow "GO"
  to be any mixed-case

Signed-off-by: Lesley Kimmel <lesley.j.kimmel@gmail.com>

* feat: Add changelog fragment for change

- Add changelog fragment for PR 6192

Signed-off-by: Lesley Kimmel <lesley.j.kimmel@gmail.com>

* feat: Improve batching

- Previous batching had shortcomings like making strict assumptions
  about the format of the incoming script and did not handle Windows-
  based scripts (e.g. \r characters). It also did not handle cases where
  there were trailing or leading whitespace characters round the 'GO'
- Added a special case for removing the Byte Order Mark (BOM) character
  that may come as part of a script when slurped from some hosts.

Signed-off-by: Lesley Kimmel <lesley.j.kimmel@gmail.com>

* feat: Use str.splitlines()

- Use of this method is cleaner

Signed-off-by: Lesley Kimmel <lesley.j.kimmel@gmail.com>

* Update changelogs/fragments/6192-allow-empty-resultsets.yml

Co-authored-by: Felix Fontein <felix@fontein.de>

* fix: Update transcribing errors

- Replace local namespace with project namespace
- Remove 'return' statement from the module.fail_json call

Signed-off-by: Lesley Kimmel <lesley.j.kimmel@gmail.com>

---------

Signed-off-by: Lesley Kimmel <lesley.j.kimmel@gmail.com>
Co-authored-by: Lesley Kimmel <lesleyk@vmware.com>
Co-authored-by: Felix Fontein <felix@fontein.de>

plugins/modules/mssql_script.py

@@ -280,14 +280,32 @@ def run_module():
         cursor = conn.cursor(as_dict=True)
         query_results_key = 'query_results_dict'
 
-    queries = script.split('\nGO\n')
+    # Process the script into batches
+    queries = []
+    current_batch = []
+    for statement in script.splitlines(keepends=True):
+        # Ignore the Byte Order Mark, if found
+        if statement.strip() == '\uFEFF':
+            continue
+
+        # Assume each 'GO' is on its own line but may have leading/trailing whitespace
+        # and be of mixed-case
+        if statement.strip().upper() != 'GO':
+            current_batch.append(statement)
+        else:
+            queries.append(''.join(current_batch))
+            current_batch = []
+    if len(current_batch) > 0:
+        queries.append(''.join(current_batch))
+
     result['changed'] = True
     if module.check_mode:
         module.exit_json(**result)
 
     query_results = []
-    try:
-        for query in queries:
+    for query in queries:
+        # Catch and exit on any bad query errors
+        try:
             cursor.execute(query, sql_params)
             qry_result = []
             rows = cursor.fetchall()
@@ -295,8 +313,17 @@ def run_module():
                 qry_result.append(rows)
                 rows = cursor.fetchall()
             query_results.append(qry_result)
-    except Exception as e:
-        return module.fail_json(msg="query failed", query=query, error=str(e), **result)
+        except Exception as e:
+            # We know we executed the statement so this error just means we have no resultset
+            # which is ok (eg UPDATE/INSERT)
+            if (
+                type(e).__name__ == 'OperationalError' and
+                str(e) == 'Statement not executed or executed statement has no resultset'
+            ):
+                query_results.append([])
+            else:
+                error_msg = '%s: %s' % (type(e).__name__, str(e))
+                module.fail_json(msg="query failed", query=query, error=error_msg, **result)
 
     # ensure that the result is json serializable
     qry_results = json.loads(json.dumps(query_results, default=clean_output))