MySQL: How do I get the AVG value in one column for entries sharing distinct values in another column? -


in case of table such:

id num   grp 1  12.3  group1 2  2.4   group2 3  7.6   group2 4  4.5   group1 5  8.9   group1 6  12.6  group1 7  1.1   group2 8  7.8   group1

i output result grid additional column have value of 9.22 in rows grp value of group1, , 3.7 in rows grp value of group2. so, in each case, average num value of rows same grp value.

i'm still learning mysql. think know components need (avg, distinct/group by, , possibly self join?), i'm struggling find right way put them together.

can please try query below, using group by of avg , join same table, can column value expectation:

select ta.id, ta.num, ta.grp , ag.avgnum ( select grp, avg(num) avgnum        tablename        group grp ) ag join  tablename ta on ta.grp = ag.grp

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