From 51c92d89389f780e01d30ce4424f8cd681c0b568 Mon Sep 17 00:00:00 2001
From: wumpz <t.warneke@gmx.net>
Date: Wed, 16 Oct 2019 23:40:42 +0200
Subject: [PATCH] fixes #862

---
 README.md                                                    | 1 +
 src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt    | 2 +-
 .../java/net/sf/jsqlparser/statement/select/SelectTest.java  | 5 +++++
 3 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 4b9bbe532..4f59614d0 100644
--- a/README.md
+++ b/README.md
@@ -65,6 +65,7 @@ Also I would like to know about needed examples or documentation stuff.
 
 ## Extensions in the latest SNAPSHOT version 3.1
 
+* allow more complex expressions for **CASE**.
 * allowed **start** as object name as column name or table name
 * introduced more positions for **!** instead of **NOT**
 * allowed more complex expressions within **if** function
diff --git a/src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt b/src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt
index f9be8c8e3..3c84de397 100644
--- a/src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt
+++ b/src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt
@@ -3234,7 +3234,7 @@ Expression CaseWhenExpression() #CaseWhenExpression:
     (
             ( clause=WhenThenSearchCondition() { whenClauses.add(clause); } )+
         |
-            (LOOKAHEAD(RegularCondition()) switchExp=RegularCondition() | switchExp=BitwiseAndOr())
+            switchExp=Condition()
              ( clause=WhenThenValue() { whenClauses.add(clause); } )+
     )
    [<K_ELSE> elseExp=Condition()]
diff --git a/src/test/java/net/sf/jsqlparser/statement/select/SelectTest.java b/src/test/java/net/sf/jsqlparser/statement/select/SelectTest.java
index 3d09cbf92..d5b2ca36d 100644
--- a/src/test/java/net/sf/jsqlparser/statement/select/SelectTest.java
+++ b/src/test/java/net/sf/jsqlparser/statement/select/SelectTest.java
@@ -1297,6 +1297,11 @@ public void testIssue235SimplifiedCase3() throws JSQLParserException {
     public void testIssue235SimplifiedCase4() throws JSQLParserException {
         assertSqlCanBeParsedAndDeparsed("SELECT CASE WHEN (CASE WHEN (CASE WHEN (CASE WHEN (1) THEN 0 END) THEN 0 END) THEN 0 END) THEN 0 END FROM a");
     }
+    
+    @Test
+    public void testIssue862CaseWhenConcat() throws JSQLParserException {
+        assertSqlCanBeParsedAndDeparsed("SELECT c1, CASE c1 || c2 WHEN '091' THEN '2' ELSE '1' END AS c11 FROM T2");
+    }
 
     @Test
     public void testReplaceAsFunction() throws JSQLParserException {