public static ShowResultSet execute(ShowStmt statement, ConnectContext context) {
        return GlobalStateMgr.getCurrentState().getShowExecutor().showExecutorVisitor.visit(statement, context);
    }
@Test
    public void testShowTableFromUnknownDatabase() throws SemanticException, DdlException {
        ShowTableStmt stmt = new ShowTableStmt("emptyDb", false, null);

        expectedEx.expect(SemanticException.class);
        expectedEx.expectMessage("Unknown database 'emptyDb'");
        ShowExecutor.execute(stmt, ctx);
    }