【導(dǎo)讀】立和維護(hù)以及前端應(yīng)用程序的開(kāi)發(fā)兩個(gè)方面。對(duì)于前者要求建立起數(shù)據(jù)一致性和。完整性強(qiáng)、數(shù)據(jù)安全性好的庫(kù)。而對(duì)于后者則要求應(yīng)用程序功能完備,易使用等。詢(xún)，打印信息以用戶(hù)管理等六個(gè)方面。系統(tǒng)的核心是添加、修改和刪除三者之間的聯(lián)系，每。完成信息的修改。刪除和密碼修改功能，并具備報(bào)表打印功能。題等方面，較為系統(tǒng)地介紹了“商品進(jìn)銷(xiāo)存”課題開(kāi)發(fā)的整個(gè)過(guò)程。

　　

【正文】 ventilators, who dumped them. Billy was a dumper. The human beings also passed canteens, which guards would fill with water. When food came in, the human beings were quiet and trusting and beautiful. They shared. Human beings in there took turns standing or lying down. The legs of those who stood were like fence posts driven into a warm ., squirming, fatting, sighing earth. The queer earth was a mosaic of sleepers who nestled like spoons. Now the train began to creep eastward. Somewhere in there was Christmas. Billy Pilgrim nestled like a spoon with the hobo on Christmas night, and he fell asleep, and he traveled in time to 1967 againto the night he was kidnapped by a flying saucer from Tralfamadore. Four Billy Pilgrim could not sleep on his daughters wedding night. He was forty four. The wedding had taken place that afternoon in a gaily striped tent in Billy39。s backyard. The stripes were orange and black. Billy and his wife, Valencia, nestled like spoons in their big double bed. They were jiggled by Magic Fingers. Valencia didn39。 t need to be jiggled to sleep. Valencia was snoring like a bandsaw. T he poor woman didn39。t have ovaries or a uterus any more. They had been removed by a surgeonby one of Billy39。s partners in the New Holiday Inn. There was a full moon. Billy got out of bed in the moonlight. He felt spooky and luminous felt as though he were wrapped in cool fur that was full of static electricity. He looked down at his bare feet. They were ivory and blue. Billy now shuffled down his upstairs hallway, knowing he was about to be kidnapped by a flying saucer. The hallway was zebra striped with darkness and moonlight. The moonlight came into the hallway through doorways of the empty rooms of Billy39。s two children, children no more. They were gone forever. Billy was guided by dread and the lack of dread. Dread told him when to stop. Lack of it told him when to move again. He stopped. He went into his daughter39。s room. Her drawers were dumped. her closet was empty. Heaped in the middle of the room were all the possessions she could not take on a honeymoon. She had a Princess telephone extension all her ownon her windowsill Its tiny night light stared at Billy. And then it rang. Billy answered. There was a drunk on the other end. Bi 39。Who killed me? he would ask. And everybody knew the answer., which was this: Billy Pilgrim.39。 Listen on the tenth night the peg was pulled out of the hasp on Billy39。s boxcar door, and the door was opened. Billy Pilgrim was lying at an angle on the cornerbrace, selfcrucified, holding himself there with a blue and ivory claw hooked over the sill of the ventilator. Billy coughed when the door was opened, and when he coughed he shit thin gruel. This was in accordance with the Third Law of Motion according to Sir Isaac Newton. This law tells us that for every action there is a reaction which is equa l and opposite in direction. This can be useful in rocketry. The train had arrived on a siding by a prison which was originally constructed as an extermination camp for Russian prisoners of war. The guards peeked inside Billy39。s car owlishly, cooed calmingly. They had never dealt w ith Americans before, but they surely understood this general sort of freight. They kne w that it was essentially a liquid which could be induced to flow slowly toward cooing and light. It was nighttime. The only light outside came from a single bulb which hung from a polehigh and far away. All was quiet outside, except for the guards, who cooed like doves. And the liquid began to flow. Gobs of it built up in the doorway, plopped to the ground. Billy was the nexttolast human being to reach the door. The hobo was the last. The hobo could not flow, could not plop. He wasn39。t liquid any more . He was stone. So it goes. Billy didn39。t. want to drop from the car to the ground. He sincerely believed that he would shatter like glass. So the guards helped him down, cooing still. T hey set him down facing the train. I t was such a dinky train now. There was a lootive, a tender, and three little boxcars. The last boxcar was the railroad guards39。 heaven on wheels. A gainin that heaven on wheelsthe table was set. Dinner was served. At the base of the pole from which the light bulb hung were three seeming haystacks. The Americans were wheedled and teased o ver to those three stacks, w hich weren39。t hay after all. They were overcoats taken from prisoners who were dead. So it goes. It was the guards39。 firmly expressed wish that every American without an overcoat should take one. The coats were cemented together with ice, so the guards used their bayos as ice picks, pric king free collars and hems and sleeves and so on, then peeling off coats and handing them out at random. The coats were stiff and domeshaped, having conformed to their piles. The coat that Billy Pilgrim got had been crumpled and frozen in such a way, and was so small, that it appeared to be not a coat but a sort of large black, threecornered hat. There were gummy stains on it, too, like crankcase drainings or old strawberry jam. There seemed to be a dead, furry animal frozen to it. The animal was in fact the coat39。s fur collar. Billy glanced dully at the coats of his neighbors. T heir coats all had brass buttons or tinsel or piping or numbers or stripe s or eagles or moons or stars dangling from them. They were soldiers39。 coats. Billy was the only one who had a coat from a dead civilian. So it goes. And Billy and the rest were encouraged to shuffle around their dinky train and into the prison camp. There wasn39。t anything wa rm or lively to attract themmerely long, low, narrow sheds by the thousands, with no lights inside. Somewhere a dog barked. With the help