SELECT min max and max min value from a part of a table in MySQL

Question

I want to select min max and max min values for each value in table1 from another table2. sample input

table2
name, value,y
f1, .01,.04
f1,.02,.05
f1,.05,.06
f1,.45,.07
f2,.03,.09
f2,.05,.02

table1
name, value
f1, .04
f2,.04

expected output
table3
name, value,min_max-value,max_min-value,y(min_max-value),y(max_min-value)
f1, .04,.02,.05,.05,.06
f2,.04,.03,.05,.09,.02

Answer 1

You can get MAX and MIN values from t2 with the following query:

SELECT
    t1.name,
    t1.value,
    (SELECT min(value) FROM table2 t2 WHERE t2.name = t1.name),
    (SELECT MAX(value) FROM table2 t2 WHERE t2.name = t1.name)
FROM table1 t1

EDIT: To get the values closer to the t1.value and corresponding y value you could do:

SELECT 
    t1.NAME, 
    t1.value, 
    (SELECT MAX(t2.value)
      FROM table2 t2
      WHERE t2.NAME = t1.NAME AND t2.value < t1.value) AS maxmin, 
    (SELECT MIN(t2.value)
      FROM table2 t2
      WHERE t2.NAME = t1.NAME AND t2.value > t1.value) AS minmax, 
    (SELECT t2.y
      FROM table2 t2
      WHERE t2.NAME = t1.NAME AND t2.value = (
            SELECT MAX(t3.value)
            FROM table2 t3
            WHERE t3.NAME = t1.NAME AND t3.value < t1.value
            )) AS ymaxmin, 
    (SELECT t2.y
      FROM table2 t2
      WHERE t2.NAME = t1.NAME AND t2.value = (
            SELECT MIN(t3.value)
            FROM table2 t3
            WHERE t3.NAME = t1.NAME AND t3.value > t1.value
            )) AS yminmax
FROM table1 t1

see it in this fiddle