Merge pull request #1 from cebe/db-constraints

Changes to db constraints

db/ConstraintFinderTrait.php

@@ -28,6 +28,25 @@
  */
 trait ConstraintFinderTrait
 {
+    /**
+     * Returns the metadata of the given type for the given table.
+     * @param string $name table name. The table name may contain schema name if any. Do not quote the table name.
+     * @param string $type metadata type.
+     * @param bool $refresh whether to reload the table metadata even if it is found in the cache.
+     * @return mixed metadata.
+     */
+    abstract protected function getTableMetadata($name, $type, $refresh);
+
+    /**
+     * Returns the metadata of the given type for all tables in the given schema.
+     * @param string $schema the schema of the metadata. Defaults to empty string, meaning the current or default schema name.
+     * @param string $type metadata type.
+     * @param bool $refresh whether to fetch the latest available table metadata. If this is `false`,
+     * cached data may be returned if available.
+     * @return array array of metadata.
+     */
+    abstract protected function getSchemaMetadata($schema, $type, $refresh);
+
     /**
      * Loads a primary key for the given table.
      * @param string $tableName table name.

db/SqlToken.php

@@ -195,17 +195,25 @@ public function getSql()
 
     /**
      * Returns whether this token (including its children) matches the specified "pattern" SQL code.
-     * Currently this implementation uses [[\yii\db\sqlite\SqlTokenizer]] to process a pattern SQL code.
-     * @param string $pattern SQL code. Everything supported in SQLite is supported here as well.
-     * In addition, `any` keyword is supported which is treated as any number of keywords, identifiers, whitespaces.
+     *
+     * Usage Example:
+     *
+     * ```php
+     * $patternToken = (new \yii\db\sqlite\SqlTokenizer('SELECT any FROM any'))->tokenize();
+     * if ($sqlToken->matches($patternToken, 0, $firstMatchIndex, $lastMatchIndex)) {
+     *     // ...
+     * }
+     * ```
+     *
+     * @param SqlToken $patternToken tokenized SQL code to match against. In addition to normal SQL, the
+     * `any` keyword is supported which will match any number of keywords, identifiers, whitespaces.
      * @param int $offset token children offset to start lookup with.
      * @param int|null $firstMatchIndex token children offset where a successful match begins.
      * @param int|null $lastMatchIndex token children offset where a successful match ends.
      * @return bool whether this token matches the pattern SQL code.
      */
-    public function matches($pattern, $offset = 0, &$firstMatchIndex = null, &$lastMatchIndex = null)
+    public function matches(SqlToken $patternToken, $offset = 0, &$firstMatchIndex = null, &$lastMatchIndex = null)
     {
-        $patternToken = (new \yii\db\sqlite\SqlTokenizer($pattern))->tokenize();
         if (!$patternToken->getHasChildren()) {
             return false;
         }

db/SqlTokenizer.php

@@ -7,8 +7,8 @@
 
 namespace yii\db;
 
+use yii\base\Component;
 use yii\base\InvalidParamException;
-use yii\base\Object;
 
 /**
  * SqlTokenizer splits an SQL query into individual SQL tokens.
@@ -28,7 +28,7 @@
  * @author Sergey Makinen <[email protected]>
  * @since 2.0.13
  */
-abstract class SqlTokenizer extends Object
+abstract class SqlTokenizer extends Component
 {
     /**
      * @var string SQL code.

db/sqlite/Schema.php

@@ -15,6 +15,7 @@
 use yii\db\Expression;
 use yii\db\ForeignKeyConstraint;
 use yii\db\IndexConstraint;
+use yii\db\SqlToken;
 use yii\db\TableSchema;
 use yii\db\Transaction;
 use yii\helpers\ArrayHelper;
@@ -146,22 +147,26 @@ protected function loadTableChecks($tableName)
         $sql = $this->db->createCommand('SELECT `sql` FROM `sqlite_master` WHERE name = :tableName', [
             ':tableName' => $tableName,
         ])->queryScalar();
+        /** @var $code SqlToken[]|SqlToken[][]|SqlToken[][][] */
         $code = (new SqlTokenizer($sql))->tokenize();
-        if (!$code[0]->matches('any CREATE any TABLE any()', 0, $firstMatchIndex, $lastMatchIndex)) {
+        $pattern = (new SqlTokenizer('any CREATE any TABLE any()'))->tokenize();
+        if (!$code[0]->matches($pattern, 0, $firstMatchIndex, $lastMatchIndex)) {
             return [];
         }
 
         $createTableToken = $code[0][$lastMatchIndex - 1];
         $result = [];
         $offset = 0;
         while (true) {
-            if (!$createTableToken->matches('any CHECK()', $offset, $firstMatchIndex, $offset)) {
+            $pattern = (new SqlTokenizer('any CHECK()'))->tokenize();
+            if (!$createTableToken->matches($pattern, $offset, $firstMatchIndex, $offset)) {
                 break;
             }
 
             $checkSql = $createTableToken[$offset - 1]->getSql();
             $name = null;
-            if (isset($createTableToken[$firstMatchIndex - 2]) && $createTableToken->matches('CONSTRAINT any', $firstMatchIndex - 2)) {
+            $pattern = (new SqlTokenizer('CONSTRAINT any'))->tokenize();
+            if (isset($createTableToken[$firstMatchIndex - 2]) && $createTableToken->matches($pattern, $firstMatchIndex - 2)) {
                 $name = $createTableToken[$firstMatchIndex - 1]->content;
             }
             $result[] = new CheckConstraint([