db->table('table2') ->select('table2.column') ->where('column', 1) ->getCompiledSelect(); $this->db->table($this->table) ->join("{$subQuery} …

databaseの接続設定は済んでいる前提 $subQuery = $this->db->select('count(*) as column_count, sample_id')->get_compiled_select('table_a'); $this->db->select('*')->join("({$subQuery}) AS table_a", 'table_a.sample_id = samples.id', 'left', fal…