[DERBY-6423] The expression syntax in CASE's THEN clause doesn't accept boolean value expression

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 10.10.2.1, 10.11.1.1
• Component/s: SQL
• Issue & fix info: Repro attached
• Assignee: Knut Anders Hatlen
• Reporter: Dag H. Wanvik
• Created: 27/Nov/13 14:54
• Updated: 09/Sep/16 09:52
• Resolved: 10/Oct/14 17:48

Description

This syntax gives an error:

> VALUES CASE WHEN 1=1 THEN (1=2) OR (3!=4) ELSE true END;
ERROR 42X01: Syntax error: Encountered "OR" at line 1, column 33.

However, this works:

> VALUES CASE WHEN 1=1 THEN ((1=2) OR (3!=4)) ELSE true END;
1    
-----
true 
1 row selected

According to the standard, the syntax after THEN should be <result>:

<result> ::=
   <result expression>
   | NULL

<result expression> ::=
   <value expression>

which should give us the full value syntax. sqlgrammar.jj uses the corresponding production "thenElseExpression" which allows NULL or aditiveExpression. I believe it should be orExpression.

Issue Links

• is depended upon by: DERBY-6424 Document thenExpression
• relates to: DERBY-5972 Grammar doesn't accept OR operator without parentheses
• relates to: DERBY-532 Support deferrable constraints
• relates to: DERBY-6759 Derby 10.10 backport issue (fall 2014)