Fixing a problem with an OP_CONCAT in WhenExpression (#1837)

* fix: Concatenation in inner ELSE statement (Second level of Case Expression) * fix: broken tests * fix: Delete lookahead(3)
JSQLParser · Aug 20, 2023 · f05cb7f · f05cb7f
1 parent 3cae390
commit f05cb7f
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Showing 2 changed files with 28 additions and 3 deletions.
diff --git a/src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt b/src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt
@@ -4796,9 +4796,7 @@ Expression CaseWhenExpression() #CaseWhenExpression:
     [
         <K_ELSE>
         (
-             LOOKAHEAD(3, {!interrupted}) "(" elseExp=CaseWhenExpression() ")" { elseExp = new Parenthesis( elseExp ); }
-              | LOOKAHEAD(3, {!interrupted}) elseExp=CaseWhenExpression()
-              | LOOKAHEAD(3, {getAsBoolean(Feature.allowComplexParsing) && !interrupted}) elseExp=Expression()
+              LOOKAHEAD({getAsBoolean(Feature.allowComplexParsing) && !interrupted}) elseExp=Expression()
               | elseExp=SimpleExpression()
         )
     ]

diff --git a/src/test/java/net/sf/jsqlparser/expression/CaseExpressionTest.java b/src/test/java/net/sf/jsqlparser/expression/CaseExpressionTest.java
@@ -82,6 +82,33 @@ public void testCaseOrSwitch() throws JSQLParserException {
         TestUtils.assertExpressionCanBeParsedAndDeparsed("CASE true OR false WHEN true THEN 1 ELSE 2 END", true);
     }
 
+    @Test
+    public void testInnerCaseWithConcatInElsePart() throws JSQLParserException {
+        String query = "SELECT \n" +
+                "CASE \n" +
+                "   WHEN 1 = 1 \n" +
+                "   THEN \n" +
+                "       CASE \n" +
+                "           WHEN 2 = 2 \n" +
+                "           THEN '2a' \n" +
+                "           ELSE \n" +
+                "               CASE \n" +
+                "                   WHEN 1 = 1 \n" +
+                "                   THEN \n" +
+                "                       CASE \n" +
+                "                           WHEN 2 = 2 \n" +
+                "                           THEN '2a' \n" +
+                "                           ELSE '' \n" +
+                "                       END \n" +
+                "                   ELSE 'b' \n" +
+                "               END || 'z'\n" +
+                "       END \n" +
+                "   ELSE 'b' \n" +
+                "END AS tmp\n" +
+                "FROM test_table";
+        TestUtils.assertSqlCanBeParsedAndDeparsed(query, true);
+    }
+
     @Test
     public void testCaseInsideBrackets() throws JSQLParserException {
         String sqlStr = "SELECT ( CASE\n"