SQL compare different rows different field values

Requirements: There are two or three columns in a table, respectively, "Cargo name", "Arrival Time", "Shipping Time", "Storage Days", the name of the goods and two kinds of "fish", "meat", now the demand is such: if the meat purchase time and the fish shipped the same time the fish show the actual "storage Days", otherwise " Storage Days "is 0, the meat" storage days "normal display.

Analysis:

1, first find out all the goods name "meat" of the arrival time

Select " Arrival Time "  from where cargo name = ' Meat '

2, see the table in each record of the shipping time in the table above, then this record to meet the "storage Days" condition

Select ( Select from ( Select" arrival time "  fromwhere goods name =" meat "where purchase time = T. Shipment time) "0 Else 0 end) Storage days  from table t

SQL compare different rows different field values