For MySQL

SELECT ROUND(MAX(lat_n)-MIN(lat_n) + MAX(long_w)-MIN(long_w), 4) FROM station;

db2 select CAST(round(max(LONG_W)- min(LONG_W),4) + round(max(LAT_N)- min(LAT_N),4) AS DECIMAL(10,4)) from STATION ;

SELECT ROUND( (MAX(LAT_N) - MIN(LAT_N)) + (MAX(LONG_W) - MIN(LONG_W)), 4 ) AS Manhattan_Distance FROM STATION;

MS SQL Server: WITH Manhattan AS(SELECT ABS(MIN(LAT_N) - MAX(LAT_N)) + ABS(MIN(LONG_W) - MAX(LONG_W)) AS distance FROM STATION
) SELECT CAST(distance AS decimal(10,4)) FROM Manhattan

select round((max(lat_n)+max(long_w))-(min(lat_n)+ min(long_w)),4) from station;

this query works in oracle