mysql 以及 oracle 查询某月份 的全部日期

//mysql 查询当前月份日期 
 1 SELECT
    DATE(
        DATE_ADD(
            SYSDATE(),
            INTERVAL - DAY (SYSDATE()) + rs.month_day DAY
        )
    ) AS av
FROM
    (
        SELECT
            @ai := @ai + 1 AS month_day
        FROM
            (
                SELECT
                    1
                UNION
                    SELECT
                        2
                    UNION
                        SELECT
                            3
                        UNION
                            SELECT
                                4
                            UNION
                                SELECT
                                    5
                                UNION
                                    SELECT
                                        6
            ) a,
            (
                SELECT
                    1
                UNION
                    SELECT
                        2
                    UNION
                        SELECT
                            3
                        UNION
                            SELECT
                                4
                            UNION
                                SELECT
                                    5
                                UNION
                                    SELECT
                                        6
            ) b,
            (SELECT @ai := 0) x
    ) rs
WHERE
    rs.month_day <= DAY (LAST_DAY(SYSDATE()));

  oracle 查询某段时间内的日期

SELECT * FROM (
        SELECT TO_CHAR(TO_DATE(#{beginTime}, 'yyyy-MM-dd') + ROWNUM - 1, 'yyyy-MM-dd') AS DATAS
        FROM DUAL
        CONNECT BY ROWNUM <= TRUNC(TO_DATE(#{endTime}, 'yyyy-MM-dd') - TO_DATE(#{beginTime}, 'yyyy-MM-dd')) + 1
 ) GROUP BY datas
ORDER BY datas