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framework/db/CheckConstraint.php

@@ -16,7 +16,7 @@ namespace yii\db;
 class CheckConstraint extends Constraint
 {
     /**
-     * @var string
+     * @var string the SQL of the `CHECK` constraint.
      */
     public $expression;
 }

framework/db/Command.php

@@ -780,13 +780,13 @@ class Command extends Component
      * The name will be properly quoted by the method.
      * @param string $table the table that the check constraint will be added to.
      * The name will be properly quoted by the method.
-     * @param string $check the SQL of the `CHECK` constraint.
+     * @param string $expression the SQL of the `CHECK` constraint.
      * @return $this the command object itself.
      * @since 2.0.13
      */
-    public function addCheck($name, $table, $check)
+    public function addCheck($name, $table, $expression)
     {
-        $sql = $this->db->getQueryBuilder()->addCheck($name, $table, $check);
+        $sql = $this->db->getQueryBuilder()->addCheck($name, $table, $expression);
 
         return $this->setSql($sql)->requireTableSchemaRefresh($table);
     }
@@ -815,13 +815,13 @@ class Command extends Component
      * The name will be properly quoted by the method.
      * @param string $column the name of the column to that the constraint will be added on.
      * The name will be properly quoted by the method.
-     * @param mixed $default default value.
+     * @param mixed $value default value.
      * @return $this the command object itself.
      * @since 2.0.13
      */
-    public function addDefaultValue($name, $table, $column, $default)
+    public function addDefaultValue($name, $table, $column, $value)
     {
-        $sql = $this->db->getQueryBuilder()->addDefaultValue($name, $table, $column, $default);
+        $sql = $this->db->getQueryBuilder()->addDefaultValue($name, $table, $column, $value);
 
         return $this->setSql($sql)->requireTableSchemaRefresh($table);
     }

framework/db/QueryBuilder.php

@@ -655,14 +655,14 @@ class QueryBuilder extends \yii\base\Object
      * The name will be properly quoted by the method.
      * @param string $table the table that the check constraint will be added to.
      * The name will be properly quoted by the method.
-     * @param string $check the SQL of the `CHECK` constraint.
+     * @param string $expression the SQL of the `CHECK` constraint.
      * @return string the SQL statement for adding a check constraint to an existing table.
      * @since 2.0.13
      */
-    public function addCheck($name, $table, $check)
+    public function addCheck($name, $table, $expression)
     {
         return 'ALTER TABLE ' . $this->db->quoteTableName($table) . ' ADD CONSTRAINT '
-            . $this->db->quoteColumnName($name) . ' CHECK (' . $this->db->quoteSql($check) . ')';
+            . $this->db->quoteColumnName($name) . ' CHECK (' . $this->db->quoteSql($expression) . ')';
     }
 
     /**
@@ -688,12 +688,12 @@ class QueryBuilder extends \yii\base\Object
      * The name will be properly quoted by the method.
      * @param string $column the name of the column to that the constraint will be added on.
      * The name will be properly quoted by the method.
-     * @param mixed $default default value.
+     * @param mixed $value default value.
      * @return string the SQL statement for adding a default value constraint to an existing table.
      * @throws NotSupportedException if this is not supported by the underlying DBMS.
      * @since 2.0.13
      */
-    public function addDefaultValue($name, $table, $column, $default)
+    public function addDefaultValue($name, $table, $column, $value)
     {
         throw new NotSupportedException($this->db->getDriverName() . ' does not support adding default value constraints.');
     }

framework/db/Schema.php

@@ -643,7 +643,7 @@ abstract class Schema extends Object
                 $cache = $schemaCache;
             }
         }
-        if (!isset($this->_tableMetadata[$name]) || $refresh) {
+        if ($refresh || !isset($this->_tableMetadata[$name])) {
             $this->loadTableMetadataFromCache($cache, $name);
         }
         if (!array_key_exists($type, $this->_tableMetadata[$name])) {
@@ -703,13 +703,13 @@ abstract class Schema extends Object
             return $row;
         }
 
-        if (!$multiple) {
+        if ($multiple) {
-            return array_change_key_case($row, CASE_LOWER);
+            return array_map(function (array $row) {
+                return array_change_key_case($row, CASE_LOWER);
+            }, $row);
         }
 
-        return array_map(function (array $row) {
+        return array_change_key_case($row, CASE_LOWER);
-            return array_change_key_case($row, CASE_LOWER);
-        }, $row);
     }
 
     /**

framework/db/SqlToken.php

@@ -63,7 +63,7 @@ class SqlToken extends Object implements \ArrayAccess
     public $parent;
 
     /**
-     * @var SqlToken[]
+     * @var SqlToken[] token children.
      */
     private $_children = [];
 
@@ -194,11 +194,14 @@ class SqlToken extends Object implements \ArrayAccess
     }
 
     /**
-     * @param string $pattern
+     * Returns whether this token (including its children) matches the specified "pattern" SQL code.
-     * @param int $offset
+     * Currently this implementation uses [[\yii\db\sqlite\SqlTokenizer]] to process a pattern SQL code.
-     * @param int|null $firstMatchIndex
+     * @param string $pattern SQL code. Everything supported in SQLite is supported here as well.
-     * @param int|null $lastMatchIndex
+     * In addition, `any` keyword is supported which is treated as any number of keywords, identifiers, whitespaces.
-     * @return bool
+     * @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)
     {
@@ -237,6 +240,8 @@ class SqlToken extends Object implements \ArrayAccess
         $firstMatchIndex = $lastMatchIndex = null;
         $wildcard = false;
         for ($index = 0, $count = count($patternToken->children); $index < $count; $index++) {
+            // Here we iterate token by token with an exception of "any" that toggles
+            // an iteration until we matched with a next pattern token or EOF.
             if ($patternToken[$index]->content === 'any') {
                 $wildcard = true;
                 continue;

framework/db/SqlTokenizer.php

@@ -34,23 +34,23 @@ abstract class SqlTokenizer extends Object
     protected $offset;
 
     /**
-     * @var \SplStack
+     * @var \SplStack stack of active tokens.
      */
     private $_tokenStack;
     /**
-     * @var SqlToken
+     * @var SqlToken active token. It's usually a top of the token stack.
      */
     private $_currentToken;
     /**
-     * @var string[]
+     * @var string[] cached substrings.
      */
     private $_substrings;
     /**
-     * @var string
+     * @var string current buffer value.
      */
     private $_buffer = '';
     /**
-     * @var SqlToken
+     * @var SqlToken resulting token of a last [[tokenize()]] call.
      */
     private $_token;
 

framework/db/cubrid/QueryBuilder.php

@@ -140,7 +140,7 @@ class QueryBuilder extends \yii\db\QueryBuilder
      * @inheritDoc
      * @throws NotSupportedException this is not supported by CUBRID.
      */
-    public function addCheck($name, $table, $check)
+    public function addCheck($name, $table, $expression)
     {
         throw new NotSupportedException(__METHOD__ . ' is not supported by CUBRID.');
     }

framework/db/cubrid/Schema.php

@@ -391,9 +391,12 @@ class Schema extends \yii\db\Schema
     }
 
     /**
-     * @param string $tableName
+     * Loads multiple types of constraints and returns the specified ones.
-     * @param string $returnType
+     * @param string $tableName table name.
-     * @return mixed
+     * @param string $returnType return type:
+     * - indexes
+     * - uniques
+     * @return mixed constraints.
      */
     private function loadTableConstraints($tableName, $returnType)
     {

framework/db/mssql/QueryBuilder.php

@@ -179,10 +179,10 @@ class QueryBuilder extends \yii\db\QueryBuilder
     /**
      * @inheritDoc
      */
-    public function addDefaultValue($name, $table, $column, $default)
+    public function addDefaultValue($name, $table, $column, $value)
     {
         return 'ALTER TABLE ' . $this->db->quoteTableName($table) . ' ADD CONSTRAINT '
-            . $this->db->quoteColumnName($name) . ' DEFAULT ' . $this->db->quoteValue($default) . ' FOR '
+            . $this->db->quoteColumnName($name) . ' DEFAULT ' . $this->db->quoteValue($value) . ' FOR '
             . $this->db->quoteColumnName($column);
     }
 

framework/db/mssql/Schema.php

@@ -158,11 +158,10 @@ SQL;
         $this->findPrimaryKeys($table);
         if ($this->findColumns($table)) {
             $this->findForeignKeys($table);
-
             return $table;
-        } else {
-            return null;
         }
+
+        return null;
     }
 
     /**
@@ -594,9 +593,15 @@ SQL;
     }
 
     /**
-     * @param string $tableName
+     * Loads multiple types of constraints and returns the specified ones.
-     * @param string $returnType
+     * @param string $tableName table name.
-     * @return mixed
+     * @param string $returnType return type:
+     * - primaryKey
+     * - foreignKeys
+     * - uniques
+     * - checks
+     * - defaults
+     * @return mixed constraints.
      */
     private function loadTableConstraints($tableName, $returnType)
     {

framework/db/mysql/QueryBuilder.php

@@ -132,7 +132,7 @@ class QueryBuilder extends \yii\db\QueryBuilder
      * @inheritDoc
      * @throws NotSupportedException this is not supported by MySQL.
      */
-    public function addCheck($name, $table, $check)
+    public function addCheck($name, $table, $expression)
     {
         throw new NotSupportedException(__METHOD__ . ' is not supported by MySQL.');
     }

framework/db/mysql/Schema.php

@@ -110,11 +110,10 @@ class Schema extends \yii\db\Schema
 
         if ($this->findColumns($table)) {
             $this->findConstraints($table);
-
             return $table;
-        } else {
-            return null;
         }
+
+        return null;
     }
 
     /**
@@ -482,9 +481,13 @@ SQL;
     }
 
     /**
-     * @param string $tableName
+     * Loads multiple types of constraints and returns the specified ones.
-     * @param string $returnType
+     * @param string $tableName table name.
-     * @return mixed
+     * @param string $returnType return type:
+     * - primaryKey
+     * - foreignKeys
+     * - uniques
+     * @return mixed constraints.
      */
     private function loadTableConstraints($tableName, $returnType)
     {

framework/db/oci/Schema.php

@@ -142,9 +142,9 @@ SQL;
         if ($this->findColumns($table)) {
             $this->findConstraints($table);
             return $table;
-        } else {
-            return null;
         }
+
+        return null;
     }
 
     /**
@@ -630,9 +630,14 @@ SQL;
     }
 
     /**
-     * @param string $tableName
+     * Loads multiple types of constraints and returns the specified ones.
-     * @param string $returnType
+     * @param string $tableName table name.
-     * @return mixed
+     * @param string $returnType return type:
+     * - primaryKey
+     * - foreignKeys
+     * - uniques
+     * - checks
+     * @return mixed constraints.
      */
     private function loadTableConstraints($tableName, $returnType)
     {

framework/db/pgsql/Schema.php

@@ -179,9 +179,9 @@ SQL;
         if ($this->findColumns($table)) {
             $this->findConstraints($table);
             return $table;
-        } else {
-            return null;
         }
+
+        return null;
     }
 
     /**
@@ -609,9 +609,14 @@ SQL;
     }
 
     /**
-     * @param string $tableName
+     * Loads multiple types of constraints and returns the specified ones.
-     * @param string $returnType
+     * @param string $tableName table name.
-     * @return mixed
+     * @param string $returnType return type:
+     * - primaryKey
+     * - foreignKeys
+     * - uniques
+     * - checks
+     * @return mixed constraints.
      */
     private function loadTableConstraints($tableName, $returnType)
     {

framework/db/sqlite/QueryBuilder.php

@@ -321,7 +321,7 @@ class QueryBuilder extends \yii\db\QueryBuilder
      * @inheritDoc
      * @throws NotSupportedException this is not supported by SQLite.
      */
-    public function addCheck($name, $table, $check)
+    public function addCheck($name, $table, $expression)
     {
         throw new NotSupportedException(__METHOD__ . ' is not supported by SQLite.');
     }
@@ -339,7 +339,7 @@ class QueryBuilder extends \yii\db\QueryBuilder
      * @inheritDoc
      * @throws NotSupportedException this is not supported by SQLite.
      */
-    public function addDefaultValue($name, $table, $column, $default)
+    public function addDefaultValue($name, $table, $column, $value)
     {
         throw new NotSupportedException(__METHOD__ . ' is not supported by SQLite.');
     }

framework/db/sqlite/Schema.php

@@ -382,9 +382,13 @@ class Schema extends \yii\db\Schema
     }
 
     /**
-     * @param string $tableName
+     * Loads multiple types of constraints and returns the specified ones.
-     * @param string $returnType
+     * @param string $tableName table name.
-     * @return mixed
+     * @param string $returnType return type:
+     * - primaryKey
+     * - indexes
+     * - uniques
+     * @return mixed constraints.
      */
     private function loadTableConstraints($tableName, $returnType)
     {