exists
"exists" rezultate au fost gasite 4
Curs Baze de date |
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CUPRINS pag
0. Introducere Aplicaţii tradiţionale bazate pe fişiere; limitări 3 1. Sisteme de Gestiune ale Bazelor de Date (SGBD) 1. 1. Istoric,comentarii 5 1. 2. Definirea sistemelor de gestiune a bazelor de date relaţionale 6 1. 3. Regulile luiCodd 7 1. 4. Criterii minimale de definire a unui SGBDR 10 1. 5. Abstractizarea datelor 12 1. 6. Scheme, corespondenţe şi instanţe 14 1. 7. Independenţa datelor 15 1. 8. Principalele componente ale unui SGBD 15 1. 9. Obiectivele unui SGBD 18 1.10.Funcţiunile unui SGBD 20 2. Modele de descriere a datelor şi modelarea conceptuală 2.1. Generalităţi, enumerări 25 2.2. Modelare E-R 2.2.1.Concepte de bază 27 2.2.2.Restricţii structurale 31 2.2.3. Chei 34 2.3. Modelul EE-R 2.3.1. Problemele modelului E-R 35 2.3.2. Superclase şi subclase ale tipurilor de entitate 36 2.3.3. Specializarea 37 2.3.4. Generalizarea 38 2.3.5. Condiţii impuse specializării şi generalizării 38 3. Algebra relaţionala 3.1. Structura relaţionala a datelor 3.1.1. Domeniu 38 3.1.2. Relaţie 39 3.1.3. Atribut 40 3.1.4. Operatorii modelului relaţional 41 3.2. Algebra relaţională şi extensiile sale 41 4. Limbaje de interogare comerciale (modelul relaţional) - SQL 4.1. Istoric, obiective 49 4.2. Clauze şi operatori SQL 4.2.1.Clauzele SELECT, FROM şi WHERE 50 4.2.2.Ordonarea tuplelor (clauza ORDER BY 55 4.2.3.Gruparea rezultatelor (clauza GROUP BY 56 4.2.4.Interogări pe mai multe tabele 58 4.2.5.Subinterogări 59 4.2.6.Operatorii ANY şi ALL 62 4.2.7.Operatorul exists 64 5. Normalizarea 5.1.Redundanţa informaţiilor şi anomalii de actualizare 66 5.2.Dependenţe funcţionale 69 5.3.Forme normale 5.3.1.Prima formă normală 72 5.3.2.A doua formă normală 74 5.3.3.A treia forma normală 76 5.3.4.Forma normală Boyce-Codd 76 6. Ghid de proiectare al bazelor de date relaţionale 6.1. Metodologia 6.1.1. Metodologia proiectării bazelor de date 80 6.1.2. Prezentarea metodologiei 80 6.1.3. Crearea modelului logic 82 6.2. Proiectarea logică a bazei de date – Exemplu 98 6.3. Utilizarea metodologiei de proiectare a bazelor de date relaţionale 101 6.3.1. Anexa. Documentarea tipurilor de entităţi în view-urile Locatari şi Cheltuieli 118 6.3.2. Anexa. Documentarea atributelor 119 6.3.3. Anexa. Documentarea tipurilor de relaţii din view-urile “Locatari” şi “Cheltuieli 120 6.3.4. Anexa. Documentarea domeniilor atributelor 121 6.3.5. Anexa Descrierea relaţiilor din view-urile “Locatari” şi “Cheltuieli 121 6.3.6. Anexa. Regulile date de întreprindere în cazul modelului “Locatari” şi “Cheltuieli 122 6.3.7. Anexa. Modelul global de date al sistemului Asociaţia de Locatari 122 7. Baze de date distribuite 7.1.Generaliăţi 124 7.2.Arhitectura unui SGBD distribuit 126 7.3.Proiectarea unei baze de date relaţionale distribuite 129 7.4.Alocarea datelor 130 7.5.Transparenţe în SGBDD 133 8. Securitate şi integritate 8.1. Integritate 142 8.2. Securitate 146 9. Tranzacţii şi concurenţă. 9.1.Tranzacţii 151 9.2. Proprietăţile tranzacţiilor 152 9.3. Controlul concurenţei 152 9.4. Tehnici optimiste 158 9.5. Controlul recuperării 159 Test de autoevaluare 162 . Baze de date |
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Baze de date Numar pagini: 161
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SQL |
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5.1. Comanda SELECT
5.1.1. Atributele comenzii SELECT 5.1.2. Operatori aritmetici 5.1.3. Aliasuri de coloane 5.1.4. Operatorul de concatenare 5.1.5. Convertirea valorilor Null cu ajutorul funcţiei NVL 5.1.6. Prevenirea selectării înregistrărilor duplicate 5.1.7. Clauza ORDER BY 5.1.8. Clauza WHERE 5.1.9. Operatori relaţionali 5.1.10. Operatori SQL 5.1.11. Operatorii logici 5.1.12. Funcţii 5.1.13. Funcţii referitoare la o singură înregistrare 5.1.14. Functii referitoare la mai multe înregistrari 5.1.15 Pseudo-coloana ROWNUM 5.1.16. Clauza GROUP BY 5.1.17. Clauza HAVING 5.1.18. Regasirea datelor din doua sau mai multe tabele 5.1.19. Operatorii pentru mulţimi 5.1.20. Subinterogări şi operatorii ANY, ALL, exists 5.1.21. Operaţii pe tabele ce conţin informaţii do structură arborescentă 5.2 Comanda INSERT 5.3. Comanda UPDATE 5.4. Comanda DELETE 5.5. Comanda TRUNCATE . Sql, comanda, select, aperatori, aritmetici, aliasuri, coloane, concatenare, convertire, valori, null, nvl, prevenire, inregistrari, duplicate, order by, where, clauza, relationali, logici, functii, rownum, group by, having, regasire, date, tabele, multimi, subinterogari, any, all, exists, structura, arborescenta, insert, update, delete, truncate |
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Baze de date Numar pagini: 42
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Anti-Social |
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In a world full of fears, perhaps the worst one a human being should have
is that to be afraid of his fellow man. The human that should be most feared is the one that has Anti-Social Personality Disorder or in laymen’s terms the psychopath. The psychopath is probably the most deviant mind that exists and treatment is not very successful because there is not a cure or drug to control it. The solution in my mind to control the problem of sociopaths is to let them live in colonies with each other. Through my research I will develop an understanding of this personality disorder and convince you the reader that my solution might be a viable solution. The sociopath is a combination of other mental illnesses that are incurred in childhood as a result of heredity, trauma and the lack of emotional development. The lack of moral or emotional development which gives a sociopath a lack of understanding for other people’s feelings which enables them to be deceitful without feeling bad about whatever they do. The under developed emotional system as explained in the video “The World of Personality Disorders volume 5” says the sociopath is “emotionally retarded” . The sociopathic behavior problems that start as a child have links to heredity, a family with a pre-disposition to perform crimes, alcoholic parents that do crimes, irresponsible behavior that persists and parents that do not discipline. The child that will eventually be a sociopath exhibits certain feeling inside that they are inadequate, shamed and because of that they are teased and made fun of. The child characteristics of a future sociopath consist of being incapable of following the rules. The youngster will skip school, bully, steal! , torment animals, run away from home and the child is likely to develop Attention................. . Anti-social |
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Engleza Numar pagini: 5
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The Picture of Dorian Gray |
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The Picture of Dorian Gray by Oscar Wilde is the story of
moral corruption by the means of aestheticism. In the novel, the well meaning artist Basil Hallward presets young Dorian Gray with a portrait of himself. After conversing with cynical Lord Henry Wotton, Dorian makes a wish which dreadfully affects his life forever. "If it were I who was to be always young, and the picture that was to grow old! For that I would give everything! Yes, there is nothing in the whole world I would not give! I would give my soul for that" (Wilde 109). As it turns out, the devil that Dorian sells his soul to is Lord Henry Wotton, who exists not only as something external to Dorian, but also as a voice within him (Bloom 107). Dorian continues to lead a life of sensuality which he learns about in a book given to him by Lord Henry. Dorian's unethical devotion to pleasure becomes his way of life. The novel underscores its disapproval of aestheticism which negatively impacts the main characters. Each of the three primary characters is an aesthete and meets some form of terrible personal doom. Basil Hallward's....................... . The, picture, of, dorian, gray, oscar, wilde |
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Engleza Numar pagini: 4
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"exists" rezultate au fost gasite 4
