Fix : remove not required columns from query.

See https://github.com/o1lab/xmysql/issues/9

lib/util/data.helper.js

@@ -38,8 +38,6 @@ exports.findObjectInArrayByKey = (key, value, objArray) => {
 exports.getSchemaQuery = function () {
   return 'select c.table_name, c.column_name, c.ordinal_position,c.column_key,c.is_nullable, c.data_type, c.column_type,c.extra,c.privileges, ' +
     'c.column_comment,c.column_default,c.data_type,c.character_maximum_length, ' +
-    'c.character_octet_length,c.numeric_precision,c.numeric_scale,c.datetime_precision,c.character_set_name, ' +
-    'c.collation_name, ' +
     'k.constraint_name, k.referenced_table_name, k.referenced_column_name, ' +
     's.index_name,s.seq_in_index ' +
     'from ' +