Merge pull request #775 from coderbuzz/patch-1

Update query-generator.js

lib/dialects/mysql/query-generator.js

@@ -377,7 +377,7 @@ module.exports = (function() {
       }, options || {})
 
       return Utils._.compact([
-        "CREATE", options.indicesType, "INDEX", options.indexName,
+        "CREATE", options.indicesType, "INDEX IF NOT EXISTS", options.indexName,
         (options.indexType ? ('USING ' + options.indexType) : undefined),
         "ON", tableName, '(' + transformedAttributes.join(', ') + ')',
         (options.parser ? "WITH PARSER " + options.parser : undefined)