create trigger portGo
after insert on wc
for each row
begin
select count(*) into @num from dataIn where port = new.name;
if @num=0 then
insert into dataIn values ('4',new.name);
end if;
end$
after insert on wc
for each row
begin
select count(*) into @num from dataIn where port = new.name;
if @num=0 then
insert into dataIn values ('4',new.name);
end if;
end$
是这样的，在做海运报价查询系统里，所有的港口，要重新统计整理嘛，故使用触发器来实现吧。
wc表是用来插入海运数据的。
dataIn表是原对照的port.
当有导入数据时，若是新港口，刚自动更新到dataIn中。
create trigger portAutoAdd
after insert on seaend
for each row
begin
select count(id) into @num from seaport where shortName = new.endP;
if @num=0 then
insert into seaport (shortName) values (new.endP);
end if;
end$
after insert on seaend
for each row
begin
select count(id) into @num from seaport where shortName = new.endP;
if @num=0 then
insert into seaport (shortName) values (new.endP);
end if;
end$