Fix error when splitting statements that contain multiple CASE clause…

…s within a BEGIN block (fixes #784).

CHANGELOG

@@ -14,6 +14,9 @@ Bug Fixes
   previously used just `strip_comments=True`. `strip_comments` did some of the
   work that `strip_whitespace` should do.
 
+* Fix error when splitting statements that contain multiple CASE clauses
+  within a BEGIN block (issue784).
+
 
 Release 0.5.0 (Apr 13, 2024)
 ----------------------------

sqlparse/engine/statement_splitter.py

@@ -17,6 +17,7 @@ def __init__(self):
     def _reset(self):
         """Set the filter attributes to its default values"""
         self._in_declare = False
+        self._in_case = False
         self._is_create = False
         self._begin_depth = 0
 
@@ -58,16 +59,18 @@ def _change_splitlevel(self, ttype, value):
                 return 1
             return 0
 
-        # Should this respect a preceding BEGIN?
-        # In CASE ... WHEN ... END this results in a split level -1.
-        # Would having multiple CASE WHEN END and a Assignment Operator
-        # cause the statement to cut off prematurely?
+        # BEGIN and CASE/WHEN both end with END
         if unified == 'END':
-            self._begin_depth = max(0, self._begin_depth - 1)
+            if not self._in_case:
+                self._begin_depth = max(0, self._begin_depth - 1)
+            else:
+                self._in_case = False
             return -1
 
         if (unified in ('IF', 'FOR', 'WHILE', 'CASE')
                 and self._is_create and self._begin_depth > 0):
+            if unified == 'CASE':
+                self._in_case = True
             return 1
 
         if unified in ('END IF', 'END FOR', 'END WHILE'):

tests/files/multiple_case_in_begin.sql

@@ -0,0 +1,8 @@
+CREATE TRIGGER mytrig
+AFTER UPDATE OF vvv ON mytable
+BEGIN
+    UPDATE aa
+        SET mycola = (CASE WHEN (A=1) THEN 2 END);
+    UPDATE bb
+        SET mycolb = (CASE WHEN (B=1) THEN 5 END);
+END;

tests/test_split.py

@@ -203,3 +203,8 @@ def test_split_strip_semicolon_procedure(load_file):
 def test_split_go(sql, num):  # issue762
     stmts = sqlparse.split(sql)
     assert len(stmts) == num
+
+
+def test_split_multiple_case_in_begin(load_file):  # issue784
+    stmts = sqlparse.split(load_file('multiple_case_in_begin.sql'))
+    assert len(stmts) == 1