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Kiu d liu Char, VarChar, Nchar, NvarChar Bit, TinyInt, SmallInt, Int, BigIntFloat, SmallMoney, Money, RealDateTimeText, Image, XMLTon t : + - * / %

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C php khai bodeclare @tn_bin kiu_d_liu [, n]Gn gi tr set @tn_bin = gi_tr | biu_thc | @bin | hm

VD: declare @x int, @y intset @y = 5set @x = @y + 3

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Cu trc lnh IFif (iu_kin) lnh . | khi_lnhelselnh . | khi_lnhkhi_lnh := beginlnh | khi_lnhend*

Cu trc lnh WHILEwhile (iu_kin) lnh | khi_lnh

Lnh ngt vng lpbreakcontinue*

Bin Cursordeclare tn_bin_cursor cursor for cu_truy_vn S dngopen tn_bin_cursor.close tn_bin_cursorHy cursordeallocate tn_bin_cursor*

Di chuyn Cursorfetch nh_v from tn_bin_cursorinto @tn_bin [, n]

nh_v := next | prior | last | first |absolute (gi_tr | bin) relative (gi_tr | bin)

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Trng thi Cursor@@fetch_status =0 :ang trong dng d liu(ln i k tip thnh cng)0:Ngoi dng d liu (ln i k tip khng thnh cng)*

V d Tnh tng s chn t 1 -> 100Declare @t int, @x intSet @t = 0 ; Set @x = 0While (@x

V d In cc sinhvien(masv char(5),tensv char(10))Declare sv cursor for select * from sinhvienOpen svDeclare @ma char(5),@ten char(10)Fetch next from sv into @ma,@tenWhile (@@fetch_status = 0) beginprint @ma + : + @ten Fetch next from sv into @ma,@tenendClose sv; Deallocate sv

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To lp th tccreate procedure tn_th_tc@tn_tham_s kiu_d_liu loi[,n]aslnh | khi_lnhTrong :loi := input(khng cn ghi)output*

Thc thi th tcexec tn_th_tc gi_tr | @bin [output] [,n] Xa th tc Drop procedure tn_th_tcThay i th tcAlter procedure tn_th_tc ..*

V d Vit th tc xa cc sinh vin theo thnh phsinhvien (masv char(5), tp char(5))

create procedure xoasinhvien @tp char(5)asbegindelete from sinhvien where tp = @tpend

exec xoasinhvien HCM*

V d Vit th tc m xem c bao nhiu sinh vin theo thnh ph.create procedure dem @tp char(5), @t int output asbeginselect @t = count(*) from sinhvien where tp = @tpenddeclare @tong intexec dem HCM , @tong outputprint @tong*

To lp hmcreate function tn_hm ( @tn_tham_s kiu loi [,n] )returns kiu_tr_vaslnh | khi_lnhTrong :loi := input(khng cn ghi)output*

Thc thi hm= tn_hm (gi_tr | @bin [output] [,n] )Xa hmDrop function tn_hmThay i hmAlter function tn_hm ..*

V d Vit hm m xem c bao nhiu sinh vin theo thnh ph.create function dem (@tp char(5)) returns intasbegindeclare @t int select @t = count(*) from sinhvien where tp = @tpreturn @tenddeclare @tong int set @tong = dbo.dem(HCM) *

V d Vit hm sinh ra m sinh vin t ng theo quy tc- M sinh vin c dng: BA0001BA : quy nh (lun c)0001 : l s VD:Hin ti sinh vin c m cao nht l BA0024Th sinh m mi l BA0025*

Create function sinhkhoa () returns char(6)AsBegin declare @max int select @max = max(cast(substring(masv,3,4) as int)) + 1from sinhvien declare @s char(6)set @s = 0000 + rtrim(cast(@max as char(4)))set @s = BA + right(@s,4)return @send*

V d vi Table Functioncreate function laydssv (@malop char(5))returns TABLEasreturn (select masv,tensv from sinhvien where malop = @malop )

select * from laydssv('QT1')*

V d vi Table Functioncreate function laydssv1 (@malop char(5))returns @btam table(masv char(5),tensv char(20)) asbegininsert into @btam select masv,tensv from sinhvien where malop = @malopreturnend

select * from laydssv1('QT1')*

By lnh c pht sinh sau nhng hnh vi thm mi hay thay i, xa trn bng.C th hy cc cp nhp trn d liuBy lnh c pht sinh thay th nhng hnh vi thm, i, xa.By s kin lu tr tch ri gi tr mi c a vo v gi tr c c xa b.Dng bng tm Inserted v deletedBy s kin cn p dng cho Login. *

Loi trigger FOR

*Lu vo d liuInsert | Update | Deleteim luLnh by s kinInsertedDeletedKhng chp nhn s thay i (RollBack)Chp nhn (Commit)

Loi trigger INSTEAD OF

*Insert | Update | DeleteLnh by s kinInsertedDeletedKhng thay i d liu

Bng tm cho by s kin inserted :Lu nhng thng tin sp c a vo d liudeleted :Lu nhng thng tin c v chun b c thay thBng tm c cu trc ging bng t s kin.VD:Cp nhp sinh vin m BA0002 vi thnh ph HCM thnh HN.=> Vo bng inserted l b (BA0002,aaa,HN)=> Vo bng deleted l b (BA0002,aaa,HCM)*

update(tn_ct) :Tr v kt qu True / False nu ct b cp nhp.columns_updated() :Tr v mt s xc nh cc ct c cp nhp. V d: Bang (c1,c2,c3,c4) Nu c2 c cp nht => 0010: kt qu 2Nu c1,c3,c4 c cp nht =>1101: kt qu 13*

S kin lng nhau c ti a 32Thay i thng s cho php lng nhaualter database tendatabaseset recursive_triggers { on | off }

Thit lp gii hn lng nhauexec sp_configure Nested Triggers n

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To triggercreate trigger tn_trigger on tn_bng{for|instead of} {insert|delete|update} aslnh | khi_lnhXa v thay i Alter | Drop trigger tn_trigger ..*

To trigger cho bng sinhvien (masv, tensv, malop)tha mn iu kin mt lp khng qu 20 ngi.

Create trigger tssv on sinhvien for insert,update AsBegindeclare @malop char(5), @ts int select @malop = malop from insertedselect @ts = count(*) from sinhvien where malop=@malopif (@ts > 20) rollback transactionend*

To trigger cho bng sinhvien (masv, tensv, trangthai)tha mn iu kin khi xa mt sinh vin tc thay i trng thi t 0 thnh 1.

Create trigger tssv on sinhvien instead of delete AsBeginupdate sinhvien set trangthai = 1where masv in (select masv from deleted)end*

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