where
"where" rezultate au fost gasite 14
Curs Baze de date |
|
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 |
|
Baze de date Numar pagini: 161
|
SQL |
|
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 |
|
Baze de date Numar pagini: 42
|
Health |
| People who have low self image, and low self esteem, are unhappy with whom they are in life. Things that are done well are often taken for granted. where as mistakes are heavily looked upon. One's position in life and previous experiences can also add to negative feelings. Constantly being told you're headed no where or that you're nothing but a failure can lead to a low self esteem and low self image. There are many things that can be done to raise self image, and self esteem. Responding to criticism positively is very important.. Health |
|
Engleza Numar pagini: 1
|
THE PLACE where I WANT TO GO |
| About New York. New, york, english, essay | |
|
Engleza Numar pagini: 3
|
The Life And Works Aristotle |
| When Plato died in 347 bc, Aristotle moved to Assos, a city in Asia Minor, where a friend of his, Hermias (died 345 bc), was ruler. There he counseled Hermias and married his niece and adopted daughter, Pythias. After Hermias was captured and executed by the Persians, Aristotle went to Pella, the Macedonian capital, where he became the tutor of the king's young son Alexander, later known as Alexander the Great. In 335, when Alexander became king, Aristotle returned to Athens and established his own school, the Lyceum. Because much of the discussion in his school took place while teachers and students were walking about the Lyceum grounds, Aristotle's school came to be known as the Peripatetic ("walking" or "strolling") school. Upon the death of Alexander in 323 bc, strong anti-Macedonian feeling developed in Athens, and Aristotle retired to a family estate in Euboea. He died there the following year. . Aristotle |
|
Engleza Numar pagini: 5
|
Winston Churchill |
|
Sir Winston Leonard Spencer Churchill was born at Blenheim Palace on Nov. 30, 1874. His father was Lord Randolph Churchill, who descended directly from the 1st duke of Marlborough, of whom Winston was to write a biography. His mother was Jennie Jerosme, an American.
Churchill's childhood was unhappy. He spent most of his time at school, something he didn't really love. His teachers caracterized him as bright, but stubborn and obstinate. He loved to read history and poetry, however, and was fascinated by soldiers and battles. From childhood he had an extraordinary memory. Winston Churchhill didn't want to go to university. Instead, he enrolled in the Royal Military College at Sandhurst. He graduated in 1894. After service in Cuba and India, he worked as a war-correspondent in Northern India, Sudan and in South Africa, where he was captured by the Boers. His daring escape made him an overnight celebrity. . Winston, churchill |
|
Engleza Numar pagini: 3
|
The Reign of Terror and the French Revolution |
| History is said to be written by the winners, but is it possible to rewrite history? In a way, the French, like many who have preceded them, and many who will proceed them have done the impossible, rewriting history. From trivial folklore, such as George Washington chopping down a cherry tree, to the incredibly wrong, the African slave trade; people's views of history can be shaped and molded. The French have done a superb job of instilling all of us with the concept that their Revolution was a fight for liberty, justice and the good of all Frenchmen everywhere. Their glorification of the Bastille with it's depictions in painting and sculpture and how the Revolution was the beginning of a new age pales to some of the events during this period. In fact, the storming of the Bastille was merely a hole in the dike, and more would follow. The National Guard, the Paris Commune, the September Massacre, are all words that the French would prefer us not to hear. These events were a subtle dénouement to an climax that was filled with both blood and pain. The Reign of Terror, or the Great Terror, was a massive culmination to the horror of the French Revolution, the gutters flowing with blood as the people of Paris watched with an entertained eye. No matter what the French may claim, if one chooses to open his eyes and read about this tragedy, they are most certainly welcome.. Reign, of, terror, french, revolution |
|
Engleza Numar pagini: 8
|
The Power of Knowledge |
| A person’s feeling can be depicted by the way he or she draws their pictures. Superiority and inferiority can be shown by the way the artist makes a person or ship larger or smaller than another person or ship. This is shown in the Spanish picture where the French ships are on the coast of America. The French ships are small and the Native Americans appear to be larger. In another picture it shows a tribe of Native Americans gathered around each other in a village. The first picture shows the Spaniards belief that the French are inferior to the Native Americans and themselves. They depict this by drawing the Native Americans much larger than the French people and even their ships. The power of the Spaniards is proven when they combine forces with the Native Americans to annihilate the French in Florida.. Knowledge |
|
Engleza Numar pagini: 1
|
Heart of Darkness Essay |
|
It seems like everywhere there is something in life that seems to be left behind. In the books I read about mystery or suspense, this always seems to be the case in such. The Heart of Darkness draws me into such depths of suspense and unknown that seem to assciate with my life.
This whole book is full of mysteries. Marlow has a heart that is full of mytery when he is stuck in Africa, and looking for a man named Kurtz. Marlow is waiting, he learns about where the place is at, what could be coming ahead. Maybe he was just acquiring some ideas of what was ahead, or who he would be working with. Why is all this senselessness happening around him? . Joseph, conrad, heart, of, darkness |
|
Engleza Numar pagini: 1
|
Plato versus Aristotle |
| "Plato and Aristotle, two philosophers in the 4th century, hold polar views on politics and philosophy in general. This fact is very cleverly illustrated by Raphael's "School of Athens" (1510-11; Stanza della Segnatura, Vatican), where Plato is portrayed looking up to the higher forms; and Aristotle is pointing down because he supports the natural sciences." . Plato, platon, aristotle, aristotel, polar views, versus |
|
Engleza Numar pagini: 3
|
Multiple Personality Disorder |
| More than two million cases can be found altogether in psychological and psychiatric records of multiple personality disorder also called dissociative identity disorder. It is often thought that multiple personality disorder is a trick, a bizarre form of "play-acting" that is committed by manipulative, attention-seeking individuals. It is not. Multiple personality disorder is a "disorder of hiding" wherein 80-90% of multiple personality disorder patients do not have a clue that they have the disorder. Most know that there is something wrong with them; many fear that they are crazy, but few know that they have a disorder.. Multiple, personality, disorder |
|
Engleza Numar pagini: 4
|
Anorexia And What Causes It |
|
Eating disorders are not new. Anorexia Nervosa was first formally diagnosed in 1874, and the symptoms have been observed as far back as 300 years ago.(Walsh and Devlin 1) Although the condition has been known for centuries, it seems to be center stage now during the last decade or so.
What is behind Anorexia? Is it inherited? Is Anorexia caused by some type of mental illness, or maybe environmental pressures? Does culture play a role in whether or not someone suffers from Anorexia? These questions are not easily answered,as we know if we have had any family members or close friends who have suffered from Anorexia. It's not as easily diagnosed as the measles or chickenpox, where the doctor knows exactly what the cause is. We will discover that there is no one clearcut cause for Anorexia. According to Women's Health Weekly one research study collected blood from 200 families where at least two of the siblings were suffering from Anorexia, several of the test results suggest a possible link between Anorexia and a shared suseptability gene found in many of the siblings (10) . We must keep in mind that although this research is promising it is still as of yet incomplete data, which in essence makes it a theory. This by no means suggests that there is not a biological link, but that more research needs to be done. . Anorexia |
|
Engleza Numar pagini: 2
|
Jerome David Salinger The Catcher In The Rye |
|
As a novelist, J.D. Salinger belongs to a distinct group of American writers who began their literary careers during or immediately after the Second World War, the so-called “young novelists” – James Baldwin, William Styron, etc.
The Ctcher in the Rye confirmed and sustained his reputation and gained him a position as one of the most important American writers of the young generation. The book is nevertheless a first-rate novel and one of the most convincing studies of adolescence ever to be written by an American. Salinger is widely seen as a keen students of children. In 1951 he published The Catcher in the Rye – a touching psychological study of adolescence, in which he views the American way of life through the eyes of a teen-age nonconformist, Holden Caulfield, a twentieth century rival of Twain’s Huck Finn. Holden is a person whose defining quality is his inability to behave according to the strict morals and social code of the day. Salinger’s sensitive and defiant school boy defies conventions and remains innocent about them. Holden images himself protecting a group of children happily playing in a rye field, from falling into a nearby precipice: “keep picturing these little kids, playing some game in this big field of rye....Thousands of little kids, and nobody around – nobody big, I mean except me. And I am standing on the edge of some crazy cliff. What I have to do? I have to catch everybody if they start to go over the cliff. I mean – if they are running and they don’t look where they are going. I have to come out from somewhere and catch them. That’s all I do all day. I’d just be the catcher in the rye and all.”............. . Holden, salinger, catcher, in, the, rye, novel |
|
Engleza Numar pagini: 2
|
Greek Gods in the Iliad. |
|
With our view of God, it can sometimes be difficult to comprehend the actions and thinking of the Greek deities. The Christian God does not tend to take such an active role in the affairs of people's lives, where, on the other hand, the Greeks regarded direct involvement by the gods as a daily, uncontrollable part of life. Needless to say, divine intervention was a major variable in the equation of Homer's Iliad.
The gods picked who they would favour for different reasons. Except Zeus: As the symbol of supreme authority and justice, he makes judgement calls as to the other gods' involvement in the war, remains impartial, and doesn't seem to get caught up in picking favourites. Even when his own son, Sarpedon, was about to die, Zeus chose to let the outcome go unaltered. . Greek, gods, iliad, homer |
|
Engleza Numar pagini: 2
|
"where" rezultate au fost gasite 14
