Fix parsing of variables being assigned value of CASE expr within SELECT statements

For example,

$query = "SELECT  1+ 2 AS `c2`, sum(c2), sum(c3) AS `sum_c3`, 'Status'= CASE WHEN quantity > 0 THEN 'in stock' ELSE 'out of stock' END FROM test_table"

Signed-off-by: Deven Bansod <devenbansod.bits@gmail.com>

1 files changed, 8 insertions, 1 deletions

diff --git a/src/Components/Expression.php b/src/Components/Expression.php
index 1ca0596..e407960 100644
--- a/src/Components/Expression.php
+++ b/src/Components/Expression.php
@@ -33,7 +33,7 @@ class Expression extends Component
      * @var array
      */
     private static $ALLOWED_KEYWORDS = array(
-        'AS' => 1, 'DUAL' => 1, 'NULL' => 1, 'REGEXP' => 1
+        'AS' => 1, 'DUAL' => 1, 'NULL' => 1, 'REGEXP' => 1, 'CASE' => 1
     );
 
     /**
@@ -252,6 +252,13 @@ class Expression extends Component
                         }
                         $alias = true;
                         continue;
+                    } elseif ($token->value === 'CASE') {
+                        // For a use of CASE like
+                        // 'SELECT a = CASE .... END, b=1, `id`, ... FROM ...'
+                        $tempCaseExpr = CaseExpression::parse($parser, $list);
+                        $ret->expr .= CaseExpression::build($tempCaseExpr);
+                        $isExpr = true;
+                        continue;
                     }
                     $isExpr = true;
                 } elseif ($brackets === 0 && count($ret->expr) > 0 && ! $alias) {