Fix issue #1789

Signed-off-by: Andrey Andreev <narf@bofh.bg>
diff --git a/system/database/DB_driver.php b/system/database/DB_driver.php
index e61af91..b64b977 100644
--- a/system/database/DB_driver.php
+++ b/system/database/DB_driver.php
@@ -79,6 +79,10 @@
 	protected $_protect_identifiers		= TRUE;
 	protected $_reserved_identifiers	= array('*'); // Identifiers that should NOT be escaped
 
+	// clause and character used for LIKE escape sequences
+	protected $_like_escape_str = " ESCAPE '%s' ";
+	protected $_like_escape_chr = '!';
+
 	/**
 	 * The syntax to count rows is slightly different across different
 	 * database engines, so this string appears in each driver and is