private RouteResultset routeSelect(
SchemaConfig schema,
QueryTreeNode ast,
RouteResultset rrs,
String stmt,
LayerCachePool cachePool)
throws SQLNonTransientException {
ResultSetNode rsNode = ((CursorNode) ast).getResultSetNode();
if (rsNode instanceof SelectNode) {
if (((SelectNode) rsNode).getFromList().isEmpty()) {
// if it is a sql about system info, such as select charset etc.
return RouterUtil.routeToSingleNode(rrs, schema.getRandomDataNode(), stmt);
}
}
// standard SELECT operation
SelectParseInf parsInf = new SelectParseInf();
parsInf.ctx = new ShardingParseInfo();
SelectSQLAnalyser.analyse(parsInf, ast);
return tryRouteForTables(ast, true, rrs, schema, parsInf.ctx, stmt, cachePool);
}
