transform write query into read query (#497)

Author: staabm

.phpstan-dba-mysqli.cache

@@ -57,7 +57,6 @@ $config = new RuntimeConfiguration();
 // $config->debugMode(true);
 // $config->stringifyTypes(true);
 // $config->analyzeQueryPlans(true);
-// $config->analyzeWriteQueries(true); // requires transaction support in db schema and db driver
 
 // TODO: Put your database credentials here
 $mysqli = new mysqli('hostname', 'username', 'password', 'database');

.phpstan-dba-pdo-mysql.cache

@@ -8,4 +8,4 @@ If not configured otherwise, the following defaults are used:
 - when analyzing a php8+ codebase, [`PDO::ERRMODE_EXCEPTION` error handling](https://www.php.net/manual/en/pdo.error-handling.php) is assumed.
 - when analyzing a php8.1+ codebase, [`mysqli_report(\MYSQLI_REPORT_ERROR | \MYSQLI_REPORT_STRICT);` error handling](https://www.php.net/mysqli_report) is assumed.
 - the fetch mode defaults to `QueryReflector::FETCH_TYPE_BOTH`, but can be configured using the [`defaultFetchMode`](https://github.com/staabm/phpstan-dba/tree/main/src/QueryReflection/RuntimeConfiguration.php) option.
-- only readable queries are analyzed per default. In case your database schema and database driver support transactions, you may consider enabled writable queries using the [`analyzeWriteQueries`](https://github.com/staabm/phpstan-dba/tree/main/src/QueryReflection/RuntimeConfiguration.php) option.
+- read and write queries are analyzed per default. you may consider disable write query analysis using the [`analyzeWriteQueries`](https://github.com/staabm/phpstan-dba/tree/main/src/QueryReflection/RuntimeConfiguration.php) option.

README.md

@@ -62,7 +62,7 @@ public function analyze(string $query): QueryPlanResult
                 $this->connection->rollBack();
             }
         } else {
-            $this->connection->begin_transaction();
+            $this->connection->begin_transaction(\MYSQLI_TRANS_START_READ_ONLY);
 
             try {
                 $result = $this->connection->query($simulatedQuery);

docs/configuration.md

@@ -72,7 +72,7 @@ public function hashDb(): string
                 $this->connection->rollBack();
             }
         } else {
-            $this->connection->begin_transaction();
+            $this->connection->begin_transaction(\MYSQLI_TRANS_START_READ_ONLY);
 
             try {
                 $result = $this->connection->query($query);

src/Analyzer/QueryPlanAnalyzerMysql.php

@@ -59,18 +59,22 @@ public static function setupReflector(QueryReflector $reflector, RuntimeConfigur
 
     public function validateQueryString(string $queryString): ?Error
     {
+        $queryType = self::getQueryType($queryString);
+
         if (self::getRuntimeConfiguration()->isAnalyzingWriteQueries()) {
-            if (!\in_array(self::getQueryType($queryString), [
-                'SELECT',
+            if (\in_array($queryType, [
                 'INSERT',
                 'DELETE',
                 'UPDATE',
                 'REPLACE',
             ], true)) {
+                // turn write queries into explain, so we don't need to execute a query which might modify data
+                $queryString = 'EXPLAIN '.$queryString;
+            } elseif ('SELECT' !== $queryType) {
                 return null;
             }
         } else {
-            if ('SELECT' !== self::getQueryType($queryString)) {
+            if ('SELECT' !== $queryType) {
                 return null;
             }
         }

src/DbSchema/SchemaHasherMysql.php

@@ -46,7 +46,7 @@ final class RuntimeConfiguration
     /**
      * @var bool
      */
-    private $writableQueries = false;
+    private $writableQueries = true;
     /**
      * @var bool|0|positive-int
      */