Support placeholders

Author: muglug

src/Parser/ExpressionParser.php

@@ -15,6 +15,7 @@
 use Vimeo\MysqlEngine\Query\Expression\IntervalOperatorExpression;
 use Vimeo\MysqlEngine\Query\Expression\StubExpression;
 use Vimeo\MysqlEngine\Query\Expression\ParameterExpression;
+use Vimeo\MysqlEngine\Query\Expression\PlaceholderExpression;
 use Vimeo\MysqlEngine\Query\Expression\PositionExpression;
 use Vimeo\MysqlEngine\Query\Expression\RowExpression;
 use Vimeo\MysqlEngine\Query\Expression\SubqueryExpression;
@@ -228,6 +229,10 @@ public function tokenToExpression(Token $token)
 
                 if ($token->value === '?') {
                     if ($token->parameterName === null) {
+                        if ($token->parameterOffset !== null) {
+                            return new PlaceholderExpression($token, $token->parameterOffset);
+                        }
+
                         throw new ParserException('? encountered with unknown offset');
                     }
 

src/Parser/SQLParser.php

@@ -208,6 +208,10 @@ private static function buildTokenListFromLexemes(array $tokens)
     {
         $out = [];
         $count = \count($tokens);
+
+        // all parameters in PDO MySQL start at 1. I know, it's weird.
+        $parameter_offset = 1;
+
         foreach ($tokens as $i => [$token, $start]) {
             $trimmed_token = \trim($token);
 
@@ -342,7 +346,12 @@ private static function buildTokenListFromLexemes(array $tokens)
                 }
             }
 
-            if ($token_upper === 'NULL') {
+            if ($token_upper === '?') {
+                $token_obj = new Token(TokenType::IDENTIFIER, $token, $token, $start);
+                $token_obj->parameterOffset = $parameter_offset;
+                $out[] = $token_obj;
+                $parameter_offset++;
+            } elseif ($token_upper === 'NULL') {
                 $out[] = new Token(TokenType::NULL_CONSTANT, $token, $token, $start);
             } elseif ($token_upper === 'TRUE') {
                 $out[] = new Token(TokenType::NUMERIC_CONSTANT, '1', $token, $start);

src/Parser/Token.php

@@ -30,6 +30,11 @@ class Token
      */
     public $parameterName;
 
+    /**
+     * @var ?int
+     */
+    public $parameterOffset;
+
     /**
      * @param TokenType::* $type
      */

src/Processor/Expression/Evaluator.php

@@ -93,6 +93,13 @@ public static function evaluate(
             case \Vimeo\MysqlEngine\Query\Expression\ParameterExpression::class:
                 return ParameterEvaluator::evaluate($scope, $expr);
 
+            case \Vimeo\MysqlEngine\Query\Expression\PlaceholderExpression::class:
+                if (\array_key_exists($expr->offset, $scope->parameters)) {
+                    return $scope->parameters[$expr->offset];
+                }
+
+                throw new ProcessorException('Parameter offset ' . $expr->offset . ' out of range');
+
             default:
                 throw new ProcessorException('Unsupported expression ' . get_class($expr));
         }
@@ -226,25 +233,7 @@ public static function getColumnSchema(
 
             case \Vimeo\MysqlEngine\Query\Expression\ParameterExpression::class:
                 if (\array_key_exists($expr->parameterName, $scope->parameters)) {
-                    $value = $scope->parameters[$expr->parameterName];
-
-                    if (\is_int($value)) {
-                        return $expr->column = new Column\IntColumn(false, 10);
-                    }
-
-                    if (\is_float($value)) {
-                        return $expr->column = new Column\FloatColumn(10, 2);
-                    }
-
-                    if (\is_bool($value)) {
-                        return $expr->column = new Column\TinyInt(true, 1);
-                    }
-
-                    if ($value === null) {
-                        return $expr->column = new Column\NullColumn();
-                    }
-
-                    return new Column\Varchar(10);
+                    return self::getColumnTypeFromValue($expr, $scope->parameters[$expr->parameterName]);
                 }
 
                 // When MySQL can't figure out a variable column's type
@@ -255,6 +244,32 @@ public static function getColumnSchema(
         return $expr->column = new Column\Varchar(10);
     }
 
+    /**
+     * @param mixed $value
+     */
+    private static function getColumnTypeFromValue(
+        \Vimeo\MysqlEngine\Query\Expression\Expression $expr,
+        $value
+    ) : Column {
+        if (\is_int($value)) {
+            return $expr->column = new Column\IntColumn(false, 10);
+        }
+
+        if (\is_float($value)) {
+            return $expr->column = new Column\FloatColumn(10, 2);
+        }
+
+        if (\is_bool($value)) {
+            return $expr->column = new Column\TinyInt(true, 1);
+        }
+
+        if ($value === null) {
+            return $expr->column = new Column\NullColumn();
+        }
+
+        return new Column\Varchar(10);
+    }
+
     /**
      * @param  list<Column>  $types
      */

src/Processor/Scope.php

@@ -9,7 +9,7 @@ class Scope
     public $variables = [];
 
     /**
-     * @var array<string, mixed>
+     * @var array<string|int, mixed>
      */
     public $parameters = [];
 

src/Query/Expression/PlaceholderExpression.php

@@ -0,0 +1,33 @@
+<?php
+namespace Vimeo\MysqlEngine\Query\Expression;
+
+use Vimeo\MysqlEngine\Parser\Token;
+use Vimeo\MysqlEngine\TokenType;
+
+final class PlaceholderExpression extends Expression
+{
+    /**
+     * @var int
+     */
+    public $offset;
+
+    /**
+     * @param Token $token
+     */
+    public function __construct(Token $token, int $offset)
+    {
+        $this->type = $token->type;
+        $this->precedence = 0;
+        $this->offset = $offset;
+        $this->name = '?';
+        $this->start = $token->start;
+    }
+
+    /**
+     * @return bool
+     */
+    public function isWellFormed()
+    {
+        return true;
+    }
+}

tests/EndToEndTest.php

@@ -66,6 +66,23 @@ public function testSelectFetchAssocConverted()
         );
     }
 
+    public function testPlaceholders()
+    {
+        $pdo = self::getConnectionToFullDB(false);
+
+        $query = $pdo->prepare("SELECT id FROM `video_game_characters` WHERE `id` > ? ORDER BY `id` ASC");
+        $query->bindValue(1, 14);
+        $query->execute();
+
+        $this->assertSame(
+            [
+                ['id' => 15],
+                ['id' => 16]
+            ],
+            $query->fetchAll(\PDO::FETCH_ASSOC)
+        );
+    }
+
     public function testSumEmptySet()
     {
         $pdo = self::getConnectionToFullDB(false);