sql server - Creating Trigger for Insert row and Delete row -

i attempting create trigger if row inserted , if row deleted. if row inserted print statement give 1 message, , if row deleted print statement give message. teacher used example, ddl statements instead of dml statements put in. question how can obtain equivalent, making dml statements can work? far output says else print statement whether row inserted or deleted. don't beleive counts insert statement @ all.

here schema.

create table dbo.customers (     customerid          int             not null identity primary key,     customerfname       varchar(30)     not null,     customerlname       varchar(30)     not null,     customeraddress1    varchar(50)     not null,     customeraddress2    varchar(50)     null,     customercity        varchar(50)     not null,     customerstate       char(2)         not null,     customerzipcode     int             not null,     customerhome        varchar(20)     not null,     customercell        varchar(20)     not null,     customeremail       varchar(50)     null ); 

this data had.

customerid  customerfname   customerlname   customeraddress1    customeraddress2        customercity    customerstate   customerzipcode customerhome    customercell        customeremail 1   jane    swanson 123 negley ave  apartment #3    pittsburgh  pa  15222   (412) 555 -     6678    (412) 555 - 6789    jane.swanson@gmail.com 2   phillip connely 167 warble st   null    pittsburgh  pa  15212   (412) 555 - 9463    (412) 555 - 6797    philli123@yahoo.com 3   alfred  mansley 41 wild place   apartment #4    pittsburgh  pa  15205   (412) 555 - 9371    (412) 555 - 4259    mansleyman592@gmail.com 4   angel   smith   2050 morningside ave    null    pittsburgh  pa  15222   (412) 555 - 6931    (412) 555 - 1135    angie.smith01@hotmail.com 5   walter  weezley 2670 butler st  null    pittsburgh  pa  15210   (412) 567 - 6931    (412) 666 - 1256    walt.disney2012@gmail.com 

trigger creation

create trigger table_update    on customers after insert, delete     if exists (select 1 inserted)         print 'the company has gained customers.'     else        print 'the company has lost customers.' 

test

insert customers values('pter', 'jackson', '1240 wlnut st', 'apartment #1', 'pittsburgh', 'pa', 15232, '(724) 789 - 1234', '(724) 555 - 8706', 'pete.jack43@yahoo.com');  delete customers customerfname = 'pter'; 

upon inserting row message:

the company has gained customers.

msg 2601, level 14, state 1, procedure table_update, line 15
cannot insert duplicate key row in object 'dbo.customers' unique index 'ix_customername'. duplicate key value (jackson, pter).
statement has been terminated.

upon deleting right after message:

the company has lost customers.
(1 row(s) affected)
(1 row(s) affected)
(0 row(s) affected)

my desired output add 1 row or delete 1 row. if choose delete non existing row seems have affect above. seems doing creating more 1 row. have unique key on customer name, if customer appears more once error occur. how can output inserting 1 row inserted , not system trying insert same row multiple times?

how using special tables inserted or deleted

if exists (select 1 inserted)     print 'the company has gained customers.' else     print 'the company has lost customers.'