Servery Zastosunkiv: Systemy Keruvannya Bazamy Danykh, Khmarni Obchyslennya, Null, Firebird, Proofpoint, Microsoft SQL Server, Onlive, Informix

Dzherelo: Wikipedia. Storinky: 32. Hlavy: Systemy keruvannya bazamy danykh, Khmarni obchyslennya, Null, Firebird, Proofpoint, Microsoft SQL Server, OnLive, Informix, PostgreSQL, Veb-zastosunok, Joli OS, SQLite, Systema keruvannya bazamy danykh, Server zastosunkiv, ColdFusion, Windows Azure, Relyatsiy na alhebra, CDS/ISIS, Microsoft Office 365, ACID, ODBC, PhpMyAdmin, Prohramne zabezpechennya yak posluha, Superklyuch, Microsoft Access, JBoss Application Server, Kexi, Relyatsiy na SKBD, Zope, AfterLogic MailSuite Lite, Era tekhnolohiy, Windows Communication Foundation, EnterpriseDB Advanced Server, SQL Server Integration Services, Oracle WebLogic Server, CRUD, HSQLDB, Pohlyad, Amazon S3, DB2. Vytyah: Null - spetsial na poznachka, yaka vykorystovuyet sya v SQL dlya poznachennya toho, shcho znachennya ne isnuye v bazi danykh. Vvedeno vynakhidnykom relyatsiy noi modeli danykh Edharom Koddom, SQL Null sluhuye dlya vykonannya vymohy, shcho vsi diy sno relyatsiy ni systemy keruvannya bazamy danykh (RSKBD) pidtrymuyut predstavlennya -vidsutn oi i neprydatnoi informatsii -. Kodd takozh vviv vykorystannya maloi litery hrets koi omeha ( ) yak symvola dlya predstavlennya Null v teorii baz danykh. NULL takozh ye zarezervovanym slovom v SQL, yake vkazuye na spetsial nu poznachku Null. Null buv prychynoyu superechok i debativ cherez svoyu asotsiatsiyu z triy kovoyu lohikoyu, osoblyvykh vymoh z y oho vykorystannya v instruktsii SQL JOIN, i spetsial noi obrobky ahrehatnymy funktsiyamy ta operatoramy hrupuvannya SQL. Khocha osoblyvi funktsii ta predykaty pravyl no obroblyayut Null, oponenty vidchuvayut, shcho pidtrymka tsiyei mozhlyvosti vvodyt nepotribnu skladnist i superechlyvist v relyatsiy nu model danykh. Null buv vvedenyy Edharom Koddom yak zasib dlya predstavlennya vidsutnikh danykh v relyatsiy niy modeli nezalezhno vid typu danykh. Vpodal shomu vin opublikuvav svoyu stattyu v dvokh chastynakh v chasopysi ComputerWorld, v tsiy statti vin prezentuvav 12 ...