[增添]添加了datasource的setting数据库以及默认值

vendor/doctrine/dbal/src/ConnectionException.php

@@ -0,0 +1,31 @@
+<?php
+
+namespace Doctrine\DBAL;
+
+/** @psalm-immutable */
+class ConnectionException extends Exception
+{
+    /** @return ConnectionException */
+    public static function commitFailedRollbackOnly()
+    {
+        return new self('Transaction commit failed because the transaction has been marked for rollback only.');
+    }
+
+    /** @return ConnectionException */
+    public static function noActiveTransaction()
+    {
+        return new self('There is no active transaction.');
+    }
+
+    /** @return ConnectionException */
+    public static function savepointsNotSupported()
+    {
+        return new self('Savepoints are not supported by this driver.');
+    }
+
+    /** @return ConnectionException */
+    public static function mayNotAlterNestedTransactionWithSavepointsInTransaction()
+    {
+        return new self('May not alter the nested transaction with savepoints behavior while a transaction is open.');
+    }
+}