groupBy 后附加数量和每组百分比

SELECT
    i_State,
    n,
    ROUND( n / s * 100, 4 ) rat 
FROM
    (
    SELECT
        * 
    FROM
        ( SELECT i_State, COUNT( 1 ) n FROM planinfo GROUP BY i_State ) t1
        INNER JOIN ( SELECT COUNT( 1 ) s FROM planinfo ) t2 ON 1 = 1 
    ) t