[DBAL-2546] Fixed the failure of `Functional\StatementTest::testFetchLongBlob()` on pdo_sqlsrv

The test is partially skipped due to:

1. Fetching blob as binary string from pdo_sqlsrv requires using `PDOStatement::bindColumn()` and `PDOStatement::fetch(PDO::FETCH_BIND)` which are not supported by the DBAL.
2. Setting encoding on the connection level is not supported: https://msdn.microsoft.com/en-us/library/ff628164(v=sql.105).aspx

lib/Doctrine/DBAL/Driver/PDOSqlsrv/Connection.php

@@ -28,6 +28,15 @@ use Doctrine\DBAL\Driver\PDOConnection;
  */
 class Connection extends PDOConnection implements \Doctrine\DBAL\Driver\Connection
 {
+    /**
+     * {@inheritdoc}
+     */
+    public function __construct($dsn, $user = null, $password = null, array $options = null)
+    {
+        parent::__construct($dsn, $user, $password, $options);
+        $this->setAttribute(\PDO::ATTR_STATEMENT_CLASS, array(Statement::class, array()));
+    }
+
     /**
      * @override
      */

lib/Doctrine/DBAL/Driver/PDOSqlsrv/Statement.php

+<?php
+/*
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * This software consists of voluntary contributions made by many individuals
+ * and is licensed under the MIT license. For more information, see
+ * <http://www.doctrine-project.org>.
+ */
+
+namespace Doctrine\DBAL\Driver\PDOSqlsrv;
+
+use Doctrine\DBAL\Driver\PDOStatement;
+use PDO;
+
+/**
+ * PDO SQL Server Statement
+ */
+class Statement extends PDOStatement
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function bindParam($column, &$variable, $type = PDO::PARAM_STR, $length = null, $driverOptions = null)
+    {
+        if ($type === PDO::PARAM_LOB && $driverOptions === null) {
+            $driverOptions = PDO::SQLSRV_ENCODING_BINARY;
+        }
+
+        return parent::bindParam($column, $variable, $type, $length, $driverOptions);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function bindValue($param, $value, $type = PDO::PARAM_STR)
+    {
+        return $this->bindParam($param, $value, $type);
+    }
+}

tests/Doctrine/Tests/DBAL/Functional/StatementTest.php

@@ -112,7 +112,12 @@ EOF
             ->convertToPHPValue(
                 $stmt->fetchColumn(),
                 $this->_conn->getDatabasePlatform()
-        );
+            );
+
+        if ($this->_conn->getDriver()->getName() === 'pdo_sqlsrv') {
+            $this->markTestSkipped('Skipping on pdo_sqlsrv due to https://github.com/Microsoft/msphpsql/issues/270');
+        }
+
         $this->assertSame($contents, stream_get_contents($stream));
     }