add support for column comments in SQL Server

lib/Doctrine/DBAL/Platforms/SQLServerPlatform.php

@@ -20,6 +20,7 @@
 namespace Doctrine\DBAL\Platforms;
 
 use Doctrine\DBAL\LockMode;
+use Doctrine\DBAL\Schema\Column;
 use Doctrine\DBAL\Schema\TableDiff;
 use Doctrine\DBAL\DBALException;
 use Doctrine\DBAL\Schema\ForeignKeyConstraint;
@@ -234,21 +235,25 @@ class SQLServerPlatform extends AbstractPlatform
     protected function _getCreateTableSQL($tableName, array $columns, array $options = array())
     {
         $defaultConstraintsSql = array();
+        $commentsSql           = array();
 
         // @todo does other code breaks because of this?
         // force primary keys to be not null
         foreach ($columns as &$column) {
+            /** @var $column \Doctrine\DBAL\Schema\Column */
             if (isset($column['primary']) && $column['primary']) {
                 $column['notnull'] = true;
             }
 
-            /**
-             * Build default constraints SQL statements
-             */
+            // Build default constraints SQL statements.
             if ( ! empty($column['default']) || is_numeric($column['default'])) {
                 $defaultConstraintsSql[] = 'ALTER TABLE ' . $tableName .
                     ' ADD' . $this->getDefaultConstraintDeclarationSQL($tableName, $column);
             }
+
+            if ( ! empty($column['comment']) || is_numeric($column['comment'])) {
+                $commentsSql[] = $this->getCreateColumnCommentSQL($tableName, $column['name'], $column['comment']);
+            }
         }
 
         $columnListSql = $this->getColumnDeclarationListSQL($columns);
@@ -289,7 +294,7 @@ class SQLServerPlatform extends AbstractPlatform
             }
         }
 
-        return array_merge($sql, $defaultConstraintsSql);
+        return array_merge($sql, $commentsSql, $defaultConstraintsSql);
     }
 
     /**
@@ -304,6 +309,37 @@ class SQLServerPlatform extends AbstractPlatform
         return 'ALTER TABLE ' . $table . ' ADD PRIMARY KEY' . $flags . ' (' . $this->getIndexFieldDeclarationListSQL($index->getQuotedColumns($this)) . ')';
     }
 
+    /**
+     * Returns the SQL statement for creating a column comment.
+     *
+     * SQL Server does not support native column comments,
+     * therefore the extended properties functionality is used
+     * as a workaround to store them.
+     * The property name used to store column comments is "MS_Description"
+     * which provides compatibility with SQL Server Management Studio,
+     * as column comments are stored in the same property there when
+     * specifying a column's "Description" attribute.
+     *
+     * @param string $tableName  The quoted table name to which the column belongs.
+     * @param string $columnName The quoted column name to create the comment for.
+     * @param string $comment    The column's comment.
+     *
+     * @return string
+     */
+    protected function getCreateColumnCommentSQL($tableName, $columnName, $comment)
+    {
+        return $this->getAddExtendedPropertySQL(
+            'MS_Description',
+            $comment,
+            'SCHEMA',
+            'dbo',
+            'TABLE',
+            $tableName,
+            'COLUMN',
+            $columnName
+        );
+    }
+
     /**
      * Returns the SQL snippet for declaring a default constraint.
      *
@@ -396,9 +432,10 @@ class SQLServerPlatform extends AbstractPlatform
      */
     public function getAlterTableSQL(TableDiff $diff)
     {
-        $queryParts = array();
-        $sql = array();
-        $columnSql = array();
+        $queryParts  = array();
+        $sql         = array();
+        $columnSql   = array();
+        $commentsSql = array();
 
         /** @var \Doctrine\DBAL\Schema\Column $column */
         foreach ($diff->addedColumns as $column) {
@@ -413,6 +450,16 @@ class SQLServerPlatform extends AbstractPlatform
                 $columnDef['name'] = $column->getQuotedName($this);
                 $queryParts[] = 'ADD' . $this->getDefaultConstraintDeclarationSQL($diff->name, $columnDef);
             }
+
+            $comment = $this->getColumnComment($column);
+
+            if ( ! empty($comment) || is_numeric($comment)) {
+                $commentsSql[] = $this->getCreateColumnCommentSQL(
+                    $diff->name,
+                    $column->getQuotedName($this),
+                    $comment
+                );
+            }
         }
 
         foreach ($diff->removedColumns as $column) {
@@ -429,9 +476,39 @@ class SQLServerPlatform extends AbstractPlatform
                 continue;
             }
 
-            $fromColumn = $columnDiff->fromColumn;
-            $fromColumnDefault = isset($fromColumn) ? $fromColumn->getDefault() : null;
-            $column = $columnDiff->column;
+            $column     = $columnDiff->column;
+            $comment    = $this->getColumnComment($column);
+            $hasComment = ! empty ($comment) || is_numeric($comment);
+
+            if ($columnDiff->fromColumn instanceof Column) {
+                $fromComment    = $this->getColumnComment($columnDiff->fromColumn);
+                $hasFromComment = ! empty ($fromComment) || is_numeric($fromComment);
+
+                if ($hasFromComment && $hasComment && $fromComment != $comment) {
+                    $commentsSql[] = $this->getAlterColumnCommentSQL(
+                        $diff->name,
+                        $column->getQuotedName($this),
+                        $comment
+                    );
+                } elseif ($hasFromComment && ! $hasComment) {
+                    $commentsSql[] = $this->getDropColumnCommentSQL($diff->name, $column->getQuotedName($this));
+                } elseif ($hasComment) {
+                    $commentsSql[] = $this->getCreateColumnCommentSQL(
+                        $diff->name,
+                        $column->getQuotedName($this),
+                        $comment
+                    );
+                }
+            } else {
+                // todo: Original comment cannot be determined. What to do? Add, update, drop or skip?
+            }
+
+            // Do not add query part if only comment has changed.
+            if ($columnDiff->hasChanged('comment') && count($columnDiff->changedProperties) === 1) {
+                continue;
+            }
+
+            $fromColumnDefault = isset($columnDiff->fromColumn) ? $columnDiff->fromColumn->getDefault() : null;
             $columnDef = $column->toArray();
             $columnDefaultHasChanged = $columnDiff->hasChanged('default');
 
@@ -459,7 +536,9 @@ class SQLServerPlatform extends AbstractPlatform
                 continue;
             }
 
-            $sql[] = "sp_RENAME '". $diff->name. ".". $oldColumnName . "' , '".$column->getQuotedName($this)."', 'COLUMN'";
+            $sql[] = "sp_RENAME '". $diff->name. ".". $oldColumnName . "', '".$column->getQuotedName($this)."', 'COLUMN'";
+
+            // todo: Find a way how to implement column comment alteration statements for renamed columns.
 
             $columnDef = $column->toArray();
 
@@ -494,7 +573,7 @@ class SQLServerPlatform extends AbstractPlatform
             $sql[] = 'ALTER TABLE ' . $diff->name . ' ' . $query;
         }
 
-        $sql = array_merge($sql, $this->_getAlterTableIndexForeignKeySQL($diff));
+        $sql = array_merge($sql, $this->_getAlterTableIndexForeignKeySQL($diff), $commentsSql);
 
         if ($diff->newName !== false) {
             $sql[] = "sp_RENAME '" . $diff->name . "', '" . $diff->newName . "'";
@@ -520,6 +599,163 @@ class SQLServerPlatform extends AbstractPlatform
         return array_merge($sql, $tableSql, $columnSql);
     }
 
+    /**
+     * Returns the SQL statement for altering a column comment.
+     *
+     * SQL Server does not support native column comments,
+     * therefore the extended properties functionality is used
+     * as a workaround to store them.
+     * The property name used to store column comments is "MS_Description"
+     * which provides compatibility with SQL Server Management Studio,
+     * as column comments are stored in the same property there when
+     * specifying a column's "Description" attribute.
+     *
+     * @param string $tableName  The quoted table name to which the column belongs.
+     * @param string $columnName The quoted column name to alter the comment for.
+     * @param string $comment    The column's comment.
+     *
+     * @return string
+     */
+    protected function getAlterColumnCommentSQL($tableName, $columnName, $comment)
+    {
+        return $this->getUpdateExtendedPropertySQL(
+            'MS_Description',
+            $comment,
+            'SCHEMA',
+            'dbo',
+            'TABLE',
+            $tableName,
+            'COLUMN',
+            $columnName
+        );
+    }
+
+    /**
+     * Returns the SQL statement for dropping a column comment.
+     *
+     * SQL Server does not support native column comments,
+     * therefore the extended properties functionality is used
+     * as a workaround to store them.
+     * The property name used to store column comments is "MS_Description"
+     * which provides compatibility with SQL Server Management Studio,
+     * as column comments are stored in the same property there when
+     * specifying a column's "Description" attribute.
+     *
+     * @param string $tableName  The quoted table name to which the column belongs.
+     * @param string $columnName The quoted column name to drop the comment for.
+     *
+     * @return string
+     */
+    protected function getDropColumnCommentSQL($tableName, $columnName)
+    {
+        return $this->getDropExtendedPropertySQL(
+            'MS_Description',
+            'SCHEMA',
+            'dbo',
+            'TABLE',
+            $tableName,
+            'COLUMN',
+            $columnName
+        );
+    }
+
+    /**
+     * Returns the SQL statement for adding an extended property to a database object.
+     *
+     * @param string      $name       The name of the property to add.
+     * @param string|null $value      The value of the property to add.
+     * @param string|null $level0Type The type of the object at level 0 the property belongs to.
+     * @param string|null $level0Name The name of the object at level 0 the property belongs to.
+     * @param string|null $level1Type The type of the object at level 1 the property belongs to.
+     * @param string|null $level1Name The name of the object at level 1 the property belongs to.
+     * @param string|null $level2Type The type of the object at level 2 the property belongs to.
+     * @param string|null $level2Name The name of the object at level 2 the property belongs to.
+     *
+     * @return string
+     *
+     * @link http://msdn.microsoft.com/en-us/library/ms180047%28v=sql.90%29.aspx
+     */
+    public function getAddExtendedPropertySQL(
+        $name,
+        $value = null,
+        $level0Type = null,
+        $level0Name = null,
+        $level1Type = null,
+        $level1Name = null,
+        $level2Type = null,
+        $level2Name = null
+    ) {
+        return "EXEC sp_addextendedproperty " .
+            "N'" . $name . "', N'" . $value . "', " .
+            "N'" . $level0Type . "', " . $level0Name . ', ' .
+            "N'" . $level1Type . "', " . $level1Name . ', ' .
+            "N'" . $level2Type . "', " . $level2Name;
+    }
+
+    /**
+     * Returns the SQL statement for dropping an extended property from a database object.
+     *
+     * @param string      $name       The name of the property to drop.
+     * @param string|null $level0Type The type of the object at level 0 the property belongs to.
+     * @param string|null $level0Name The name of the object at level 0 the property belongs to.
+     * @param string|null $level1Type The type of the object at level 1 the property belongs to.
+     * @param string|null $level1Name The name of the object at level 1 the property belongs to.
+     * @param string|null $level2Type The type of the object at level 2 the property belongs to.
+     * @param string|null $level2Name The name of the object at level 2 the property belongs to.
+     *
+     * @return string
+     *
+     * @link http://technet.microsoft.com/en-gb/library/ms178595%28v=sql.90%29.aspx
+     */
+    public function getDropExtendedPropertySQL(
+        $name,
+        $level0Type = null,
+        $level0Name = null,
+        $level1Type = null,
+        $level1Name = null,
+        $level2Type = null,
+        $level2Name = null
+    ) {
+        return "EXEC sp_dropextendedproperty " .
+        "N'" . $name . "', " .
+        "N'" . $level0Type . "', " . $level0Name . ', ' .
+        "N'" . $level1Type . "', " . $level1Name . ', ' .
+        "N'" . $level2Type . "', " . $level2Name;
+    }
+
+    /**
+     * Returns the SQL statement for updating an extended property of a database object.
+     *
+     * @param string      $name       The name of the property to update.
+     * @param string|null $value      The value of the property to update.
+     * @param string|null $level0Type The type of the object at level 0 the property belongs to.
+     * @param string|null $level0Name The name of the object at level 0 the property belongs to.
+     * @param string|null $level1Type The type of the object at level 1 the property belongs to.
+     * @param string|null $level1Name The name of the object at level 1 the property belongs to.
+     * @param string|null $level2Type The type of the object at level 2 the property belongs to.
+     * @param string|null $level2Name The name of the object at level 2 the property belongs to.
+     *
+     * @return string
+     *
+     * @link http://msdn.microsoft.com/en-us/library/ms186885%28v=sql.90%29.aspx
+     */
+    public function getUpdateExtendedPropertySQL(
+        $name,
+        $value = null,
+        $level0Type = null,
+        $level0Name = null,
+        $level1Type = null,
+        $level1Name = null,
+        $level2Type = null,
+        $level2Name = null
+    ) {
+        return "EXEC sp_updateextendedproperty " .
+        "N'" . $name . "', N'" . $value . "', " .
+        "N'" . $level0Type . "', " . $level0Name . ', ' .
+        "N'" . $level1Type . "', " . $level1Name . ', ' .
+        "N'" . $level2Type . "', " . $level2Name;
+    }
+
     /**
      * {@inheritDoc}
      */
@@ -550,7 +786,8 @@ class SQLServerPlatform extends AbstractPlatform
                           col.scale,
                           col.precision,
                           col.is_identity AS autoincrement,
-                          col.collation_name AS collation
+                          col.collation_name AS collation,
+                          CAST(prop.value AS NVARCHAR(MAX)) AS comment -- CAST avoids driver error for sql_variant type
                 FROM      sys.columns AS col
                 JOIN      sys.types AS type
                 ON        col.user_type_id = type.user_type_id
@@ -559,6 +796,10 @@ class SQLServerPlatform extends AbstractPlatform
                 LEFT JOIN sys.default_constraints def
                 ON        col.default_object_id = def.object_id
                 AND       col.object_id = def.parent_object_id
+                LEFT JOIN sys.extended_properties AS prop
+                ON        obj.object_id = prop.major_id
+                AND       col.column_id = prop.minor_id
+                AND       prop.name = 'MS_Description'
                 WHERE     obj.type = 'U'
                 AND       obj.name = '$table'";
     }

lib/Doctrine/DBAL/Schema/SQLServerSchemaManager.php

@@ -79,7 +79,9 @@ class SQLServerSchemaManager extends AbstractSchemaManager
                 break;
         }
 
-        $type = $this->_platform->getDoctrineTypeMapping($dbType);
+        $type                   = $this->_platform->getDoctrineTypeMapping($dbType);
+        $type                   = $this->extractDoctrineTypeFromComment($tableColumn['comment'], $type);
+        $tableColumn['comment'] = $this->removeDoctrineTypeFromComment($tableColumn['comment'], $type);
 
         switch ($type) {
             case 'char':
@@ -91,14 +93,15 @@ class SQLServerSchemaManager extends AbstractSchemaManager
         }
 
         $options = array(
-            'length' => ($length == 0 || !in_array($type, array('text', 'string'))) ? null : $length,
-            'unsigned' => false,
-            'fixed' => (bool) $fixed,
-            'default' => $default !== 'NULL' ? $default : null,
-            'notnull' => (bool) $tableColumn['notnull'],
-            'scale' => $tableColumn['scale'],
-            'precision' => $tableColumn['precision'],
+            'length'        => ($length == 0 || !in_array($type, array('text', 'string'))) ? null : $length,
+            'unsigned'      => false,
+            'fixed'         => (bool) $fixed,
+            'default'       => $default !== 'NULL' ? $default : null,
+            'notnull'       => (bool) $tableColumn['notnull'],
+            'scale'         => $tableColumn['scale'],
+            'precision'     => $tableColumn['precision'],
             'autoincrement' => (bool) $tableColumn['autoincrement'],
+            'comment'       => $tableColumn['comment'] !== '' ? $tableColumn['comment'] : null,
         );
 
         $platformOptions = array(

tests/Doctrine/Tests/DBAL/Functional/Schema/SQLServerSchemaManagerTest.php

@@ -164,4 +164,169 @@ class SQLServerSchemaManagerTest extends SchemaManagerFunctionalTestCase
         $this->assertNull($columns['df_current_timestamp']->getDefault());
         $this->assertEquals(666, $columns['df_integer']->getDefault());
     }
+
+    /**
+     * @group DBAL-543
+     */
+    public function testColumnComments()
+    {
+        $table = new Table('sqlsrv_column_comment');
+        $table->addColumn('id', 'integer', array('autoincrement' => true));
+        $table->addColumn('comment_null', 'integer', array('comment' => null));
+        $table->addColumn('comment_false', 'integer', array('comment' => false));
+        $table->addColumn('comment_empty_string', 'integer', array('comment' => ''));
+        $table->addColumn('comment_integer_0', 'integer', array('comment' => 0));
+        $table->addColumn('comment_float_0', 'integer', array('comment' => 0.0));
+        $table->addColumn('comment_string_0', 'integer', array('comment' => '0'));
+        $table->addColumn('comment', 'integer', array('comment' => 'Doctrine 0wnz you!'));
+        $table->addColumn('`comment_quoted`', 'integer', array('comment' => 'Doctrine 0wnz comments for explicitely quoted columns!'));
+        $table->addColumn('create', 'integer', array('comment' => 'Doctrine 0wnz comments for reserved keyword columns!'));
+        $table->addColumn('commented_type', 'object');
+        $table->addColumn('commented_type_with_comment', 'array', array('comment' => 'Doctrine array type.'));
+        $table->setPrimaryKey(array('id'));
+
+        $this->_sm->createTable($table);
+
+        $columns = $this->_sm->listTableColumns("sqlsrv_column_comment");
+        $this->assertEquals(12, count($columns));
+        $this->assertNull($columns['id']->getComment());
+        $this->assertNull($columns['comment_null']->getComment());
+        $this->assertNull($columns['comment_false']->getComment());
+        $this->assertNull($columns['comment_empty_string']->getComment());
+        $this->assertEquals('0', $columns['comment_integer_0']->getComment());
+        $this->assertEquals('0', $columns['comment_float_0']->getComment());
+        $this->assertEquals('0', $columns['comment_string_0']->getComment());
+        $this->assertEquals('Doctrine 0wnz you!', $columns['comment']->getComment());
+        $this->assertEquals('Doctrine 0wnz comments for explicitely quoted columns!', $columns['comment_quoted']->getComment());
+        $this->assertEquals('Doctrine 0wnz comments for reserved keyword columns!', $columns['[create]']->getComment());
+        $this->assertNull($columns['commented_type']->getComment());
+        $this->assertEquals('Doctrine array type.', $columns['commented_type_with_comment']->getComment());
+
+        $tableDiff = new TableDiff('sqlsrv_column_comment');
+        $tableDiff->fromTable = $table;
+        $tableDiff->addedColumns['added_comment_none'] = new Column('added_comment_none', Type::getType('integer'));
+        $tableDiff->addedColumns['added_comment_null'] = new Column('added_comment_null', Type::getType('integer'), array('comment' => null));
+        $tableDiff->addedColumns['added_comment_false'] = new Column('added_comment_false', Type::getType('integer'), array('comment' => false));
+        $tableDiff->addedColumns['added_comment_empty_string'] = new Column('added_comment_empty_string', Type::getType('integer'), array('comment' => ''));
+        $tableDiff->addedColumns['added_comment_integer_0'] = new Column('added_comment_integer_0', Type::getType('integer'), array('comment' => 0));
+        $tableDiff->addedColumns['added_comment_float_0'] = new Column('added_comment_float_0', Type::getType('integer'), array('comment' => 0.0));
+        $tableDiff->addedColumns['added_comment_string_0'] = new Column('added_comment_string_0', Type::getType('integer'), array('comment' => '0'));
+        $tableDiff->addedColumns['added_comment'] = new Column('added_comment', Type::getType('integer'), array('comment' => 'Doctrine'));
+        $tableDiff->addedColumns['`added_comment_quoted`'] = new Column('`added_comment_quoted`', Type::getType('integer'), array('comment' => 'rulez'));
+        $tableDiff->addedColumns['select'] = new Column('select', Type::getType('integer'), array('comment' => '666'));
+        $tableDiff->addedColumns['added_commented_type'] = new Column('added_commented_type', Type::getType('object'));
+        $tableDiff->addedColumns['added_commented_type_with_comment'] = new Column('added_commented_type_with_comment', Type::getType('array'), array('comment' => '666'));
+
+        $tableDiff->renamedColumns['comment_float_0'] = new Column('comment_double_0', Type::getType('decimal'), array('comment' => 'Double for real!'));
+
+        // Add comment to non-commented column.
+        $tableDiff->changedColumns['id'] = new ColumnDiff(
+            'id',
+            new Column('id', Type::getType('integer'), array('autoincrement' => true, 'comment' => 'primary')),
+            array('comment'),
+            new Column('id', Type::getType('integer'), array('autoincrement' => true))
+        );
+
+        // Remove comment from null-commented column.
+        $tableDiff->changedColumns['comment_null'] = new ColumnDiff(
+            'comment_null',
+            new Column('comment_null', Type::getType('string')),
+            array('type'),
+            new Column('comment_null', Type::getType('integer'), array('comment' => null))
+        );
+
+        // Add comment to false-commented column.
+        $tableDiff->changedColumns['comment_false'] = new ColumnDiff(
+            'comment_false',
+            new Column('comment_false', Type::getType('integer'), array('comment' => 'false')),
+            array('comment'),
+            new Column('comment_false', Type::getType('integer'), array('comment' => false))
+        );
+
+        // Change type to custom type from empty string commented column.
+        $tableDiff->changedColumns['comment_empty_string'] = new ColumnDiff(
+            'comment_empty_string',
+            new Column('comment_empty_string', Type::getType('object')),
+            array('type'),
+            new Column('comment_empty_string', Type::getType('integer'), array('comment' => ''))
+        );
+
+        // Change comment to false-comment from zero-string commented column.
+        $tableDiff->changedColumns['comment_string_0'] = new ColumnDiff(
+            'comment_string_0',
+            new Column('comment_string_0', Type::getType('integer'), array('comment' => false)),
+            array('comment'),
+            new Column('comment_string_0', Type::getType('integer'), array('comment' => '0'))
+        );
+
+        // Remove comment from regular commented column.
+        $tableDiff->changedColumns['comment'] = new ColumnDiff(
+            'comment',
+            new Column('comment', Type::getType('integer')),
+            array('comment'),
+            new Column('comment', Type::getType('integer'), array('comment' => 'Doctrine 0wnz you!'))
+        );
+
+        // Change comment and change type to custom type from regular commented column.
+        $tableDiff->changedColumns['`comment_quoted`'] = new ColumnDiff(
+            '`comment_quoted`',
+            new Column('`comment_quoted`', Type::getType('array'), array('comment' => 'Doctrine array.')),
+            array('comment', 'type'),
+            new Column('`comment_quoted`', Type::getType('integer'), array('comment' => 'Doctrine 0wnz you!'))
+        );
+
+        // Remove comment and change type to custom type from regular commented column.
+        $tableDiff->changedColumns['create'] = new ColumnDiff(
+            'create',
+            new Column('create', Type::getType('object')),
+            array('comment', 'type'),
+            new Column('create', Type::getType('integer'), array('comment' => 'Doctrine 0wnz comments for reserved keyword columns!'))
+        );
+
+        // Add comment and change custom type to regular type from non-commented column.
+        $tableDiff->changedColumns['commented_type'] = new ColumnDiff(
+            'commented_type',
+            new Column('commented_type', Type::getType('integer'), array('comment' => 'foo')),
+            array('comment', 'type'),
+            new Column('commented_type', Type::getType('object'))
+        );
+
+        // Remove comment from commented custom type column.
+        $tableDiff->changedColumns['commented_type_with_comment'] = new ColumnDiff(
+            'commented_type_with_comment',
+            new Column('commented_type_with_comment', Type::getType('array')),
+            array('comment'),
+            new Column('commented_type_with_comment', Type::getType('array'), array('comment' => 'Doctrine array type.'))
+        );
+
+        $tableDiff->removedColumns['comment_integer_0'] = new Column('comment_integer_0', Type::getType('integer'), array('comment' => 0));
+
+        $this->_sm->alterTable($tableDiff);
+
+        $columns = $this->_sm->listTableColumns("sqlsrv_column_comment");
+        $this->assertEquals(23, count($columns));
+        $this->assertEquals('primary', $columns['id']->getComment());
+        $this->assertNull($columns['comment_null']->getComment());
+        $this->assertEquals('false', $columns['comment_false']->getComment());
+        $this->assertNull($columns['comment_empty_string']->getComment());
+        $this->assertEquals('0', $columns['comment_double_0']->getComment());
+        $this->assertNull($columns['comment_string_0']->getComment());
+        $this->assertNull($columns['comment']->getComment());
+        $this->assertEquals('Doctrine array.', $columns['comment_quoted']->getComment());
+        $this->assertNull($columns['[create]']->getComment());
+        $this->assertEquals('foo', $columns['commented_type']->getComment());
+        $this->assertNull($columns['commented_type_with_comment']->getComment());
+        $this->assertNull($columns['added_comment_none']->getComment());
+        $this->assertNull($columns['added_comment_null']->getComment());
+        $this->assertNull($columns['added_comment_false']->getComment());
+        $this->assertNull($columns['added_comment_empty_string']->getComment());
+        $this->assertEquals('0', $columns['added_comment_integer_0']->getComment());
+        $this->assertEquals('0', $columns['added_comment_float_0']->getComment());
+        $this->assertEquals('0', $columns['added_comment_string_0']->getComment());
+        $this->assertEquals('Doctrine', $columns['added_comment']->getComment());
+        $this->assertEquals('rulez', $columns['added_comment_quoted']->getComment());
+        $this->assertEquals('666', $columns['[select]']->getComment());
+        $this->assertNull($columns['added_commented_type']->getComment());
+        $this->assertEquals('666', $columns['added_commented_type_with_comment']->getComment());
+    }
 }

tests/Doctrine/Tests/DBAL/Functional/Schema/SchemaManagerFunctionalTestCase.php

@@ -522,7 +522,9 @@ class SchemaManagerFunctionalTestCase extends \Doctrine\Tests\DbalFunctionalTest
      */
     public function testGetColumnComment()
     {
-        if (!$this->_conn->getDatabasePlatform()->supportsInlineColumnComments() && !$this->_conn->getDatabasePlatform()->supportsCommentOnStatement()) {
+        if ( ! $this->_conn->getDatabasePlatform()->supportsInlineColumnComments() &&
+             ! $this->_conn->getDatabasePlatform()->supportsCommentOnStatement() &&
+             ! $this->_conn->getDatabasePlatform()->getName() == 'mssql') {
             $this->markTestSkipped('Database does not support column comments.');
         }
 
@@ -556,7 +558,9 @@ class SchemaManagerFunctionalTestCase extends \Doctrine\Tests\DbalFunctionalTest
      */
     public function testAutomaticallyAppendCommentOnMarkedColumns()
     {
-        if (!$this->_conn->getDatabasePlatform()->supportsInlineColumnComments() && !$this->_conn->getDatabasePlatform()->supportsCommentOnStatement()) {
+        if ( ! $this->_conn->getDatabasePlatform()->supportsInlineColumnComments() &&
+             ! $this->_conn->getDatabasePlatform()->supportsCommentOnStatement() &&
+             ! $this->_conn->getDatabasePlatform()->getName() == 'mssql') {
             $this->markTestSkipped('Database does not support column comments.');
         }
 

tests/Doctrine/Tests/DBAL/Platforms/SQLServerPlatformTest.php

@@ -3,6 +3,10 @@
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\DBAL\Platforms\SQLServer2008Platform;
+use Doctrine\DBAL\Schema\Column;
+use Doctrine\DBAL\Schema\ColumnDiff;
+use Doctrine\DBAL\Schema\Table;
+use Doctrine\DBAL\Schema\TableDiff;
 use Doctrine\DBAL\Types\Type;
 
 class SQLServerPlatformTest extends AbstractPlatformTestCase
@@ -342,4 +346,247 @@ class SQLServerPlatformTest extends AbstractPlatformTestCase
             $this->assertEquals($expected, $actual);
         }
     }
+
+    /**
+     * @group DBAL-543
+     */
+    public function getCreateTableColumnCommentsSQL()
+    {
+        return array(
+            "CREATE TABLE test (id INT NOT NULL, PRIMARY KEY (id))",
+            "EXEC sp_addextendedproperty N'MS_Description', N'This is a comment', N'SCHEMA', dbo, N'TABLE', test, N'COLUMN', id",
+        );
+    }
+
+    /**
+     * @group DBAL-543
+     */
+    public function getAlterTableColumnCommentsSQL()
+    {
+        return array(
+            "ALTER TABLE mytable ADD quota INT NOT NULL",
+            "EXEC sp_addextendedproperty N'MS_Description', N'A comment', N'SCHEMA', dbo, N'TABLE', mytable, N'COLUMN', quota",
+            // todo
+            //"EXEC sp_addextendedproperty N'MS_Description', N'B comment', N'SCHEMA', dbo, N'TABLE', mytable, N'COLUMN', baz",
+        );
+    }
+
+    /**
+     * @group DBAL-543
+     */
+    public function getCreateTableColumnTypeCommentsSQL()
+    {
+        return array(
+            "CREATE TABLE test (id INT NOT NULL, data VARCHAR(MAX) NOT NULL, PRIMARY KEY (id))",
+            "EXEC sp_addextendedproperty N'MS_Description', N'(DC2Type:array)', N'SCHEMA', dbo, N'TABLE', test, N'COLUMN', data",
+        );
+    }
+
+    /**
+     * @group DBAL-543
+     */
+    public function testGeneratesCreateTableSQLWithColumnComments()
+    {
+        $table = new Table('mytable');
+        $table->addColumn('id', 'integer', array('autoincrement' => true));
+        $table->addColumn('comment_null', 'integer', array('comment' => null));
+        $table->addColumn('comment_false', 'integer', array('comment' => false));
+        $table->addColumn('comment_empty_string', 'integer', array('comment' => ''));
+        $table->addColumn('comment_integer_0', 'integer', array('comment' => 0));
+        $table->addColumn('comment_float_0', 'integer', array('comment' => 0.0));
+        $table->addColumn('comment_string_0', 'integer', array('comment' => '0'));
+        $table->addColumn('comment', 'integer', array('comment' => 'Doctrine 0wnz you!'));
+        $table->addColumn('`comment_quoted`', 'integer', array('comment' => 'Doctrine 0wnz comments for explicitely quoted columns!'));
+        $table->addColumn('create', 'integer', array('comment' => 'Doctrine 0wnz comments for reserved keyword columns!'));
+        $table->addColumn('commented_type', 'object');
+        $table->addColumn('commented_type_with_comment', 'array', array('comment' => 'Doctrine array type.'));
+        $table->setPrimaryKey(array('id'));
+
+        $this->assertEquals(
+            array(
+                "CREATE TABLE mytable (id INT IDENTITY NOT NULL, comment_null INT NOT NULL, comment_false INT NOT NULL, comment_empty_string INT NOT NULL, comment_integer_0 INT NOT NULL, comment_float_0 INT NOT NULL, comment_string_0 INT NOT NULL, comment INT NOT NULL, [comment_quoted] INT NOT NULL, [create] INT NOT NULL, commented_type VARCHAR(MAX) NOT NULL, commented_type_with_comment VARCHAR(MAX) NOT NULL, PRIMARY KEY (id))",
+                "EXEC sp_addextendedproperty N'MS_Description', N'0', N'SCHEMA', dbo, N'TABLE', mytable, N'COLUMN', comment_integer_0",
+                "EXEC sp_addextendedproperty N'MS_Description', N'0', N'SCHEMA', dbo, N'TABLE', mytable, N'COLUMN', comment_float_0",
+                "EXEC sp_addextendedproperty N'MS_Description', N'0', N'SCHEMA', dbo, N'TABLE', mytable, N'COLUMN', comment_string_0",
+                "EXEC sp_addextendedproperty N'MS_Description', N'Doctrine 0wnz you!', N'SCHEMA', dbo, N'TABLE', mytable, N'COLUMN', comment",
+                "EXEC sp_addextendedproperty N'MS_Description', N'Doctrine 0wnz comments for explicitely quoted columns!', N'SCHEMA', dbo, N'TABLE', mytable, N'COLUMN', [comment_quoted]",
+                "EXEC sp_addextendedproperty N'MS_Description', N'Doctrine 0wnz comments for reserved keyword columns!', N'SCHEMA', dbo, N'TABLE', mytable, N'COLUMN', [create]",
+                "EXEC sp_addextendedproperty N'MS_Description', N'(DC2Type:object)', N'SCHEMA', dbo, N'TABLE', mytable, N'COLUMN', commented_type",
+                "EXEC sp_addextendedproperty N'MS_Description', N'Doctrine array type.(DC2Type:array)', N'SCHEMA', dbo, N'TABLE', mytable, N'COLUMN', commented_type_with_comment",
+            ),
+            $this->_platform->getCreateTableSQL($table)
+        );
+    }
+
+    /**
+     * @group DBAL-543
+     */
+    public function testGeneratesAlterTableSQLWithColumnComments()
+    {
+        $table = new Table('mytable');
+        $table->addColumn('id', 'integer', array('autoincrement' => true));
+        $table->addColumn('comment_null', 'integer', array('comment' => null));
+        $table->addColumn('comment_false', 'integer', array('comment' => false));
+        $table->addColumn('comment_empty_string', 'integer', array('comment' => ''));
+        $table->addColumn('comment_integer_0', 'integer', array('comment' => 0));
+        $table->addColumn('comment_float_0', 'integer', array('comment' => 0.0));
+        $table->addColumn('comment_string_0', 'integer', array('comment' => '0'));
+        $table->addColumn('comment', 'integer', array('comment' => 'Doctrine 0wnz you!'));
+        $table->addColumn('`comment_quoted`', 'integer', array('comment' => 'Doctrine 0wnz comments for explicitely quoted columns!'));
+        $table->addColumn('create', 'integer', array('comment' => 'Doctrine 0wnz comments for reserved keyword columns!'));
+        $table->addColumn('commented_type', 'object');
+        $table->addColumn('commented_type_with_comment', 'array', array('comment' => 'Doctrine array type.'));
+        $table->setPrimaryKey(array('id'));
+
+        $tableDiff = new TableDiff('mytable');
+        $tableDiff->fromTable = $table;
+        $tableDiff->addedColumns['added_comment_none'] = new Column('added_comment_none', Type::getType('integer'));
+        $tableDiff->addedColumns['added_comment_null'] = new Column('added_comment_null', Type::getType('integer'), array('comment' => null));
+        $tableDiff->addedColumns['added_comment_false'] = new Column('added_comment_false', Type::getType('integer'), array('comment' => false));
+        $tableDiff->addedColumns['added_comment_empty_string'] = new Column('added_comment_empty_string', Type::getType('integer'), array('comment' => ''));
+        $tableDiff->addedColumns['added_comment_integer_0'] = new Column('added_comment_integer_0', Type::getType('integer'), array('comment' => 0));
+        $tableDiff->addedColumns['added_comment_float_0'] = new Column('added_comment_float_0', Type::getType('integer'), array('comment' => 0.0));
+        $tableDiff->addedColumns['added_comment_string_0'] = new Column('added_comment_string_0', Type::getType('integer'), array('comment' => '0'));
+        $tableDiff->addedColumns['added_comment'] = new Column('added_comment', Type::getType('integer'), array('comment' => 'Doctrine'));
+        $tableDiff->addedColumns['`added_comment_quoted`'] = new Column('`added_comment_quoted`', Type::getType('integer'), array('comment' => 'rulez'));
+        $tableDiff->addedColumns['select'] = new Column('select', Type::getType('integer'), array('comment' => '666'));
+        $tableDiff->addedColumns['added_commented_type'] = new Column('added_commented_type', Type::getType('object'));
+        $tableDiff->addedColumns['added_commented_type_with_comment'] = new Column('added_commented_type_with_comment', Type::getType('array'), array('comment' => '666'));
+
+        $tableDiff->renamedColumns['comment_float_0'] = new Column('comment_double_0', Type::getType('decimal'), array('comment' => 'Double for real!'));
+
+        // Add comment to non-commented column.
+        $tableDiff->changedColumns['id'] = new ColumnDiff(
+            'id',
+            new Column('id', Type::getType('integer'), array('autoincrement' => true, 'comment' => 'primary')),
+            array('comment'),
+            new Column('id', Type::getType('integer'), array('autoincrement' => true))
+        );
+
+        // Remove comment from null-commented column.
+        $tableDiff->changedColumns['comment_null'] = new ColumnDiff(
+            'comment_null',
+            new Column('comment_null', Type::getType('string')),
+            array('type'),
+            new Column('comment_null', Type::getType('integer'), array('comment' => null))
+        );
+
+        // Add comment to false-commented column.
+        $tableDiff->changedColumns['comment_false'] = new ColumnDiff(
+            'comment_false',
+            new Column('comment_false', Type::getType('integer'), array('comment' => 'false')),
+            array('comment'),
+            new Column('comment_false', Type::getType('integer'), array('comment' => false))
+        );
+
+        // Change type to custom type from empty string commented column.
+        $tableDiff->changedColumns['comment_empty_string'] = new ColumnDiff(
+            'comment_empty_string',
+            new Column('comment_empty_string', Type::getType('object')),
+            array('type'),
+            new Column('comment_empty_string', Type::getType('integer'), array('comment' => ''))
+        );
+
+        // Change comment to false-comment from zero-string commented column.
+        $tableDiff->changedColumns['comment_string_0'] = new ColumnDiff(
+            'comment_string_0',
+            new Column('comment_string_0', Type::getType('integer'), array('comment' => false)),
+            array('comment'),
+            new Column('comment_string_0', Type::getType('integer'), array('comment' => '0'))
+        );
+
+        // Remove comment from regular commented column.
+        $tableDiff->changedColumns['comment'] = new ColumnDiff(
+            'comment',
+            new Column('comment', Type::getType('integer')),
+            array('comment'),
+            new Column('comment', Type::getType('integer'), array('comment' => 'Doctrine 0wnz you!'))
+        );
+
+        // Change comment and change type to custom type from regular commented column.
+        $tableDiff->changedColumns['`comment_quoted`'] = new ColumnDiff(
+            '`comment_quoted`',
+            new Column('`comment_quoted`', Type::getType('array'), array('comment' => 'Doctrine array.')),
+            array('comment', 'type'),
+            new Column('`comment_quoted`', Type::getType('integer'), array('comment' => 'Doctrine 0wnz you!'))
+        );
+
+        // Remove comment and change type to custom type from regular commented column.
+        $tableDiff->changedColumns['create'] = new ColumnDiff(
+            'create',
+            new Column('create', Type::getType('object')),
+            array('comment', 'type'),
+            new Column('create', Type::getType('integer'), array('comment' => 'Doctrine 0wnz comments for reserved keyword columns!'))
+        );
+
+        // Add comment and change custom type to regular type from non-commented column.
+        $tableDiff->changedColumns['commented_type'] = new ColumnDiff(
+            'commented_type',
+            new Column('commented_type', Type::getType('integer'), array('comment' => 'foo')),
+            array('comment', 'type'),
+            new Column('commented_type', Type::getType('object'))
+        );
+
+        // Remove comment from commented custom type column.
+        $tableDiff->changedColumns['commented_type_with_comment'] = new ColumnDiff(
+            'commented_type_with_comment',
+            new Column('commented_type_with_comment', Type::getType('array')),
+            array('comment'),
+            new Column('commented_type_with_comment', Type::getType('array'), array('comment' => 'Doctrine array type.'))
+        );
+
+        $tableDiff->removedColumns['comment_integer_0'] = new Column('comment_integer_0', Type::getType('integer'), array('comment' => 0));
+
+        $this->assertEquals(
+            array(
+                // Renamed columns.
+                "sp_RENAME 'mytable.comment_float_0', 'comment_double_0', 'COLUMN'",
+
+                // Added columns.
+                "ALTER TABLE mytable ADD added_comment_none INT NOT NULL",
+                "ALTER TABLE mytable ADD added_comment_null INT NOT NULL",
+                "ALTER TABLE mytable ADD added_comment_false INT NOT NULL",
+                "ALTER TABLE mytable ADD added_comment_empty_string INT NOT NULL",
+                "ALTER TABLE mytable ADD added_comment_integer_0 INT NOT NULL",
+                "ALTER TABLE mytable ADD added_comment_float_0 INT NOT NULL",
+                "ALTER TABLE mytable ADD added_comment_string_0 INT NOT NULL",
+                "ALTER TABLE mytable ADD added_comment INT NOT NULL",
+                "ALTER TABLE mytable ADD [added_comment_quoted] INT NOT NULL",
+                "ALTER TABLE mytable ADD [select] INT NOT NULL",
+                "ALTER TABLE mytable ADD added_commented_type VARCHAR(MAX) NOT NULL",
+                "ALTER TABLE mytable ADD added_commented_type_with_comment VARCHAR(MAX) NOT NULL",
+                "ALTER TABLE mytable DROP COLUMN comment_integer_0",
+                "ALTER TABLE mytable ALTER COLUMN comment_null NVARCHAR(255) NOT NULL",
+                "ALTER TABLE mytable ALTER COLUMN comment_empty_string VARCHAR(MAX) NOT NULL",
+                "ALTER TABLE mytable ALTER COLUMN [comment_quoted] VARCHAR(MAX) NOT NULL",
+                "ALTER TABLE mytable ALTER COLUMN [create] VARCHAR(MAX) NOT NULL",
+                "ALTER TABLE mytable ALTER COLUMN commented_type INT NOT NULL",
+
+                // Renamed columns.
+                "ALTER TABLE mytable ALTER COLUMN comment_double_0 NUMERIC(10, 0) NOT NULL",
+
+                // Added columns.
+                "EXEC sp_addextendedproperty N'MS_Description', N'0', N'SCHEMA', dbo, N'TABLE', mytable, N'COLUMN', added_comment_integer_0",
+                "EXEC sp_addextendedproperty N'MS_Description', N'0', N'SCHEMA', dbo, N'TABLE', mytable, N'COLUMN', added_comment_float_0",
+                "EXEC sp_addextendedproperty N'MS_Description', N'0', N'SCHEMA', dbo, N'TABLE', mytable, N'COLUMN', added_comment_string_0",
+                "EXEC sp_addextendedproperty N'MS_Description', N'Doctrine', N'SCHEMA', dbo, N'TABLE', mytable, N'COLUMN', added_comment",
+                "EXEC sp_addextendedproperty N'MS_Description', N'rulez', N'SCHEMA', dbo, N'TABLE', mytable, N'COLUMN', [added_comment_quoted]",
+                "EXEC sp_addextendedproperty N'MS_Description', N'666', N'SCHEMA', dbo, N'TABLE', mytable, N'COLUMN', [select]",
+                "EXEC sp_addextendedproperty N'MS_Description', N'(DC2Type:object)', N'SCHEMA', dbo, N'TABLE', mytable, N'COLUMN', added_commented_type",
+                "EXEC sp_addextendedproperty N'MS_Description', N'666(DC2Type:array)', N'SCHEMA', dbo, N'TABLE', mytable, N'COLUMN', added_commented_type_with_comment",
+
+                // Changed columns.
+                "EXEC sp_addextendedproperty N'MS_Description', N'primary', N'SCHEMA', dbo, N'TABLE', mytable, N'COLUMN', id",
+                "EXEC sp_addextendedproperty N'MS_Description', N'false', N'SCHEMA', dbo, N'TABLE', mytable, N'COLUMN', comment_false",
+                "EXEC sp_addextendedproperty N'MS_Description', N'(DC2Type:object)', N'SCHEMA', dbo, N'TABLE', mytable, N'COLUMN', comment_empty_string",
+                "EXEC sp_dropextendedproperty N'MS_Description', N'SCHEMA', dbo, N'TABLE', mytable, N'COLUMN', comment_string_0",
+                "EXEC sp_dropextendedproperty N'MS_Description', N'SCHEMA', dbo, N'TABLE', mytable, N'COLUMN', comment",
+                "EXEC sp_updateextendedproperty N'MS_Description', N'Doctrine array.(DC2Type:array)', N'SCHEMA', dbo, N'TABLE', mytable, N'COLUMN', [comment_quoted]",
+                "EXEC sp_updateextendedproperty N'MS_Description', N'(DC2Type:object)', N'SCHEMA', dbo, N'TABLE', mytable, N'COLUMN', [create]",
+                "EXEC sp_updateextendedproperty N'MS_Description', N'foo', N'SCHEMA', dbo, N'TABLE', mytable, N'COLUMN', commented_type",
+                "EXEC sp_updateextendedproperty N'MS_Description', N'(DC2Type:array)', N'SCHEMA', dbo, N'TABLE', mytable, N'COLUMN', commented_type_with_comment",
+            ),
+            $this->_platform->getAlterTableSQL($tableDiff)
+        );
+    }
 }