mysql求字段最大值和最小值

select max(字段名) from tableName limit 0,1 最大

select min(字段名) from tableName limit 0,1 最小

select * from tableName order by 字段名 DESC limit 0,1 最大

select * from tableName order by 字段名 ASC limit 0,1 最小

: select max(date) from ( select max(date) date from A unoin all select max(date) date from B ) a

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