Mau Oyamba ku Zondomeko Zachikhalidwe

Mndandanda wa mawu akuti "ubale" kapena "ubale" umatanthauzira njira yomwe deta yomwe ili mu matebulo imagwirizanitsidwa.

Otsatira ku mazambiri a dziko nthawi zambiri amavutika kuona kusiyana pakati pa database ndi spreadsheet. Amawona matebulo a deta ndikuzindikira kuti mazenerawa amakulolani kupanga ndi kufufuza deta m'njira zatsopano, koma amalephera kumvetsa tanthauzo la maubwenzi pakati pa deta yomwe imapereka teknoloji yachiyanjano.

Ubale umakulolani kuti mufotokoze mgwirizano pakati pa mitundu yosiyanasiyana yamagulu azinthu zamakono mwa njira zamphamvu. Ubalewu ukhoza kuyendetsedwa kuti upange mafunso amphamvu a pamtengowu, omwe amadziwika kuti akulowa.

Mitundu ya Maubwenzi Othandizira

Pali mitundu itatu yosiyana ya maubwenzi a deta, aliyense wotchulidwa malinga ndi chiwerengero cha mizere yomwe ingakhale yogwirizana. Chimodzi mwa mitundu itatuyi ya ubale ilipo pakati pa matebulo awiri.

Kuyanjanitsa Zokhudza Ubale: Nkhani Yapadera

Maubwenzi odziwonetsera okha amapezeka pamene pali tebulo limodzi lokha lomwe likukhudzidwa. Chitsanzo chimodzi chodziwika ndi gome la antchito lomwe liri ndi zambiri zokhudza woyang'anira aliyense wogwira ntchito. Woyang'anira aliyense ndi wantchito ndipo ali ndi woyang'anira wake. Pankhaniyi, pali chiyanjano chokhazikika payekha, monga wogwira ntchito aliyense ali ndi woyang'anira mmodzi, koma woyang'anira aliyense akhoza kukhala ndi antchito angapo.

Kupanga Ubale ndi Zachilendo Zachilendo

Inu mumapanga ubale pakati pa matebulo powatchula makiwo akunja . Nthawi zambiri, mndandanda wa Table A uli ndi mafungulo oyambirira omwe amapezeka pa Table B.

Taganiziraninso chitsanzo cha Aphunzitsi ndi Ophunzira akulemba. Tebulo la Aphunzitsi liri ndi chidziwitso, dzina, ndi gawo la maphunziro:

Aphunzitsi
InstructorID Teacher_Name Inde
001 John Doe Chingerezi
002 Jane Schmoe Masamu

Ophunzira akuphatikizapo chidziwitso, dzina, ndi chikho chachilendo chachilendo:

Ophunzira
Wophunzira Wophunzira_Name Mphunzitsi_FK
0200 Lowell Smith 001
0201 Brian Short 001
0202 Corky Mendez 002
0203 Monica Jones 001

Mutu Walimu_FK mu Ophunzila amapepala ofotokozera mfundo zofunika kwambiri za wophunzitsa mu tebulo la Aphunzitsi.

Kawirikawiri, olemba masitepe amatha kugwiritsa ntchito "PK" kapena "FK" mu dzina la mndandanda kuti azindikire mosavuta chinsinsi choyambirira kapena chigawo chachilendo chakunja.

Onani kuti magome awiriwa akusonyeza mgwirizano umodzi pakati pa aphunzitsi ndi ophunzira.

Ubale ndi Zowonetsera

Mukangowonjezera makiyi akunja ku gome, mukhoza kupanga zolemba zapamwamba zomwe zimatsimikizira kukhulupirika kwanu pakati pa matebulo awiriwo. Izi zimatsimikizira kuti maubwenzi pakati pa matebulo amakhalabe osagwirizana. Pamene tebulo limodzi liri ndi fungulo lachilendo ku gome lina, lingaliro la kufotokozera umphumphu limanena kuti makiyi aliwonse akunja amtengo wapatali mu Table B ayenera kutanthauzira ku chiwerengero chomwe chilipo mu Table A.

Kugwiritsa Ntchito Ubale

Malingana ndi deta yanu, mumagwirizanitsa mgwirizano pakati pa matebulo m'njira zosiyanasiyana. Microsoft Access imapereka wizard yomwe imakulolani kuti mumagwirizanitse matebulo komanso kuti mukhazikitse kukhulupirika kwanu.

Ngati mukulemba SQL mwachindunji, mutha kulenga tebulo aphunzitsi, kulengeza ndondomeko ya ID kukhala chinsinsi chachikulu:

DZIWANI MAPHUNZIRO Aphunzitsi (

InstructorID INT AUTO_INCREMENT PRIMARY KEY,
Teacher_Name VARCHAR (100),
Chifukwa VARCHAR (100)
);

Mukamapanga Ophunzira Patebulo, mumalengeza chikhomo cha Teacher_FK kukhala chinsinsi chachilendo chomwe chikufotokozera gawo la InstructorID mu tebulo la aphunzitsi:

DZIWANI ZINTHU Ophunzira (
Ophunzira Ophunzira MU AUTO_INCREMENT PRIMARY KEY,
Student_Name VARCHAR (100), Teacher_FK INT,
KUKHALA KWAMBIRI (Teacher_FK) REFERENCES Aphunzitsi (InstructorID))
);

Kugwiritsa Ntchito Maubwenzi Kuti Aphatikize Ma Tebulo

Mukadapanga ubale umodzi kapena angapo m'mabuku anu, mukhoza kugwiritsa ntchito mphamvu zawo pogwiritsa ntchito mafunso a SQL JOIN kuphatikiza mfundo kuchokera pa matebulo angapo. Mtundu wowonjezeka kwambiri wojowina ndi SQL INNER JOIN, kapena kuphweka kosavuta. Mtumiki woterewu amabwezeretsa zolemba zonse zomwe zimakwaniritsa zojambulidwa kuchokera ku matebulo angapo. Mwachitsanzo, ichi CHIMENE chidzabwezeretsa Student_Name, Teacher_Name, ndi Course komwe makiyi akunja mwa Ophunzira akuphatikizira chofunikira kwambiri mu tebulo la aphunzitsi:

SANKANI Ophunzira.Student_Name, Aphunzitsi.Teacher_Name, Teachers.Course
Kuchokera Ophunzira
INNER JOIN Aphunzitsi
PA Ophunzira.Teacher_FK = Aphunzitsi.InstructorID;

Mawu awa akupereka tebulo chinachake chonga ichi:

Gome lobwezeretsedwa kuchokera ku SQL Join Statement

Student_NameTeacher_NameCourseLowell SmithJohn DoeEnglishBrian ShortJohn DoeEnglishCorky MendezJane SchmoeMathMonica JonesJohn DoeEnglish