1、mysql中update中嵌套select

update A inner join(select id,name from B) c on A.id = c.id set A.name = c.name;

2、msql中的update嵌套条件判断

#更改金属量,品位，矿石量
UPDATE
    nm_mining_reserves_associated_elements
set
    ore_quantity_total = ore_quantity_proven + ore_quantity_probable,
    amount_proven = (
    CASE
        WHEN associated_elements_name = '金' or associated_elements_name ='银' THEN ore_quantity_proven * grade_proven / 1000000
    ELSE ore_quantity_proven * grade_proven / 100
    END
    ),
        amount_probable = (
    CASE
        WHEN associated_elements_name = '金' or associated_elements_name ='银' THEN ore_quantity_probable * grade_probable /         1000000
    ELSE ore_quantity_probable * grade_probable / 100
    END
    ),
    amount_total = amount_proven + amount_probable,
    grade_total = (
    CASE
        WHEN associated_elements_name = '金' or associated_elements_name ='银' THEN amount_total * 1000000 / ore_quantity_total
    ELSE amount_total * 100 / ore_quantity_total
    END
    )