mile米乐m6е®Ңж•ҙжҖ§зәҰжқҹжҳҜдёҖз»„е®Ңж•ҙжҖ§и§„еҲҷзҡ„йӣҶеҗҲпјҢе®ғжҳҜеҜ№ж•°жҚ®жЁЎеһӢдёӯж•°жҚ®еҸҠе…¶иҒ”зі»жүҖе…·жңүзҡ„еҲ¶зәҰе’Ңдҫқиө–жҖ§и§„еҲҷпјҢз”ЁжқҘдҝқиҜҒж•°жҚ®зҡ„жӯЈзЎ®жҖ§пјҢжңүж•ҲжҖ§е’Ңе…је®№жҖ§гҖӮдҫӢеҰӮпјҢеңЁе…ізі»жЁЎеһӢдёӯпјҢд»»дҪ•е…і什么是数据完整性规mile米乐m6则(з®Җиҝ°е…ізі»зҡ„е®Ңж•ҙжҖ§)е…ізі»ж•°жҚ®еә“е®Ңж•ҙжҖ§и§„еҲҷеҜ№и®ҫи®Ўе…·жңүиүҜеҘҪз»“жһ„зҡ„ж•°жҚ®еә“жқҘиҜҙйқһеёёйҮҚиҰҒгҖӮи®ёеӨҡ(дҪҶдёҚжҳҜжүҖжңү)RDBMSдјҡејәеҲ¶иҮӘеҠЁжү§иЎҢе®Ңж•ҙжҖ§и§„еҲҷгҖӮе®һдҪ“е®Ңж•ҙжҖ§:жүҖжңүдё»зҒеҖје”ҜдёҖ,дё»зҒзҡ„д»»дҪ•йғЁ

1、O(и§ҰеҸ‘е®Ңж•ҙжҖ§жЈҖжҹҘзҡ„ж•°жҚ®еә“ж“ҚдҪң,з«ӢеҚіжЈҖжҹҘиҝҳжҳҜ延иҝҹжЈҖжҹҘгҖӮA(ж•°жҚ®еҜ№иұЎиҰҒж»Ўи¶ізҡ„ж–ӯиЁҖжҲ–иҜӯд№ү规еҲҷC(еҸ—AдҪңз”Ёзҡ„ж•°жҚ®еҜ№иұЎеҖјзҡ„и°“иҜҚP

2、ж•°жҚ®е®Ңж•ҙжҖ§еҲҶдёәд»ҘдёӢзұ»гҖӮпјҲ1пјүеҹҹе®Ңж•ҙжҖ§пјҡжҳҜжҢҮдёҖдёӘеҲ—зҡ„иҫ“е…Ҙжңүж•ҲжҖ§пјҢжҳҜеҗҰе…Ғи®ёдёәз©әеҖјгҖӮејәеҲ¶еҹҹе®Ңж•ҙжҖ§зҡ„ж–№жі•жңүпјҡйҷҗеҲ¶зұ»еһӢ

3、ж•°жҚ®еә“е®Ңж•ҙжҖ§()жҳҜжҢҮж•°жҚ®еә“дёӯж•°жҚ®зҡ„жӯЈзЎ®жҖ§е’Ңзӣёе®№жҖ§гҖӮж•°жҚ®еә“е®Ңж•ҙжҖ§з”ұеҗ„з§Қеҗ„ж·зҡ„е®Ңж•ҙжҖ§зәҰжқҹжқҘдҝқиҜҒ,еӣжӯӨеҸҜд»ҘиҜҙж•°жҚ®еә“е®Ңж•ҙжҖ§и®ҫи®Ўе°ұжҳҜж•°жҚ®еә“е®Ңж•ҙ

4、дёүгҖҒз”ЁжҲ·е®ҡд№үзҡ„е®Ңж•ҙжҖ§пјҲUser-пјүд»»дҪ•е…ізі»ж•°жҚ®еә“зі»з»ҹйғҪеә”иҜҘж”ҜжҢҒе®һдҪ“е®Ңж•ҙжҖ§е’ҢеҸӮз…§е®Ңж•ҙжҖ§гҖӮйҷӨжӯӨд№ӢеӨ–пјҢдёҚеҗҢзҡ„е…ізі»ж•°жҚ®еә“зі»з»ҹж№жҚ®е…¶еә”з”ЁзҺҜеўғзҡ„дёҚеҗҢпјҢеҫҖ

5、еӯҳеӮЁеңЁж•°жҚ®еә“дёӯзҡ„жүҖжңүж•°жҚ®еҖјеқҮжӯЈзЎ®зҡ„зҠ¶жҖҒгҖӮеҰӮжһңж•°жҚ®еә“дёӯеӯҳеӮЁжңүдёҚжӯЈзЎ®зҡ„ж•°жҚ®еҖјпјҢеҲҷиҜҘж•°жҚ®еә“з§°дёәе·Ідё§еӨұж•°жҚ®е®Ңж•ҙжҖ§гҖӮж•°

жңүж—¶жҲ‘们жғіжҡӮж—¶жҲ–ж°ёд№…ең°ж¶ҲйҷӨзәҰжқҹгҖӮдҪҶжҳҜ并没жңүжҸҗдҫӣеҲйҷӨзәҰжқҹзҡ„ж–№жі•гҖӮеҸӘе…Ғи®ёзҰҒз”ЁеӨ–й”®зәҰжқҹжҲ–CHECKзәҰжқҹ,иҖҢеҗҢж—¶дҝқжҢҒзәҰжқҹзҡ„е®Ңж•ҙжҖ§гҖӮзҰҒз”ЁдёҖдёӘж•°什么是数据完整性规mile米乐m6则(з®Җиҝ°е…ізі»зҡ„е®Ңж•ҙжҖ§)第дәmile米乐m6ҢжӯҘ:жҸ’е…Ҙж•°жҚ®_age(Sdept,Avg_age),AVG(Sage);RDBMSеңЁжү§иЎҢжҸ’е…ҘиҜӯеҸҘж—¶дјҡжЈҖжҹҘжүҖжҸ’е…ғз»„жҳҜеҗҰзҙеқҸиЎЁдёҠе·Іе®ҡд№ү