[MySQL]日付が歯抜けのデータを結合して日付毎に整理されたテーブルを作る

SELECT '2018-01-01' + INTERVAL seq_no DAY AS date
FROM (SELECT @seq_no := 0 AS seq_no
      UNION
      SELECT @seq_no := @seq_no + 1 AS seq_no FROM information_schema.COLUMNS
      LIMIT 10) tmp;

SELECT
    date_table.date AS '日付',
    IFNULL(table2.商品入荷数, 0) AS '入荷数',
    IFNULL(table1.商品販売数, 0) AS '販売数'
FROM (SELECT '2018-01-01' + INTERVAL seq_no DAY AS date
      FROM (SELECT @seq_no := 0 AS seq_no
            UNION
            SELECT @seq_no := @seq_no + 1 AS seq_no FROM information_schema.COLUMNS
            LIMIT 10) tmp) date_table
LEFT JOIN table1 ON table1.日付 = date_table.date
LEFT JOIN table2 ON table2.日付 = date_table.date