Prefix quoted string vals with N in mssql

lib/sql-string.js

@@ -13,6 +13,7 @@ SqlString.escapeId = function(val, forbidQualified) {
 };
 
 SqlString.escape = function(val, timeZone, dialect, format) {
+  var prependN = false;
   if (val === undefined || val === null) {
     return 'NULL';
   }
@@ -27,6 +28,11 @@ SqlString.escape = function(val, timeZone, dialect, format) {
     return '' + !!val;
   case 'number':
     return val + '';
+  case 'string':
+    // In mssql, prepend N to all quoted vals which are originally a string (for
+    // unicode compatibility)
+    prependN = dialect === 'mssql';
+    break;
   }
 
   if (val instanceof Date) {
@@ -66,7 +72,7 @@ SqlString.escape = function(val, timeZone, dialect, format) {
       }
     });
   }
-  return "'" + val + "'";
+  return (prependN ? "N'" : "'") + val + "'";
 };
 
 SqlString.format = function(sql, values, timeZone, dialect) {