mysql-if-null -isnull ifnull

SELECT 
    id, IF(report.type = 'P', abs(amount), -1*abs(amount)) as amount
FROM  report

SELECT 
        id
        , IF(type = 'P', IFNULL(amount,0), IFNULL(amount,0) * -1) as amount
FROM    report

mysql-isnull
mysql-ifnull
mysql-if-null
MYSQL-NULL


e.g.
select
if(isnull(NameOfOverseaCo),'',NameOfOverseaCo),
if(isnull(AddrOfOverseaCo),'',AddrOfOverseaCo)
from tableName;