]]>
2 i=-20;
3 涓婇潰涓孌靛緢綆鍗曠殑浠ｇ爜錛屽鏋滆緭鍑轟細(xì)鏄粈涔?鍛紵
浠婂ぉ緹ら噷鐨勬柊瀛++鍚屽闂垜錛寀nsighed char 鍜宑har 鏈夊暐鍖哄埆錛屼笂闈㈢殑杈撳嚭浼?xì)鏈変粈涔?涓嶅悓
鍦ㄨ繖閲岋紝鎴戝厛閯欒涓涓嬭嚜宸憋紝鎴戠洿瑙傜殑鐞嗚В涓洪氬父鐨?棣栦綅絎﹀彿浣嶏紝鐒跺悗涓笅鐨勫氨鏄緭鍏ユ棤絎﹀彿鐨勩傚ソ鍚э紝浼拌鍚勪綅鐪嬪畼璇存垜澶彍錛屼絾紜疄鏄緭鍑虹殑緇撴灉鍜屾垜鎯崇殑涓嶅ぇ涓鏍鳳紝濡傛灉鍚勪綅娌℃槑鐧芥垜璇寸殑鏄粈涔堥棶棰橈紝鍙互璇曚竴涓嬨傜劧鍚庡洖鏉ョ湅涓嬮潰鐨勫唴瀹廣?br>
銆?br>
In an unsigned type, all the bits represent the value. If a type is defined for a particular machine to use 8 bits, then the unsigned version of this type could hold the values 0 through 255.
鏃犵鍙峰瀷涓紝鎵鏈夌殑浣嶉兘琛ㄧず鏁板箋傚鏋滃湪鏌愮鏈哄櫒涓紝瀹氫箟涓縐嶇被鍨嬩嬌鐢?8 浣嶈〃紺猴紝閭ｄ箞榪欑綾誨瀷鐨? unsigned 鍨嬪彲浠ュ彇鍊?0 鍒?255銆?/p>
The C++ standard does not define how signed types are represented at the bit level. Instead, each compiler is free to decide how it will represent signed types. These representations can affect the range of values that a signed type can hold. We are guaranteed that an 8-bit signed type will hold at least the values from 127 through 127; many implementations allow values from 128 through 127.
C++ 鏍囧噯騫舵湭瀹氫箟 signed 綾誨瀷濡備綍鐢ㄤ綅鏉ヨ〃紺猴紝鑰屾槸鐢辨瘡涓紪璇戝櫒鑷敱鍐沖畾濡備綍琛ㄧず signed 綾誨瀷銆傝繖浜涜〃紺烘柟寮忎細(xì)褰卞搷 signed 綾誨瀷鐨勫彇鍊艱寖鍥淬? 浣?signed 綾誨瀷鐨勫彇鍊艱偗瀹氳嚦灝戞槸浠?-127 鍒?127錛屼絾涔熸湁璁稿瀹炵幇鍏佽鍙栧間粠 -128 鍒?127銆?/p>
Under the most common strategy for representing signed integral types, we can view one of the bits as a sign bit. Whenever the sign bit is 1, the value is negative; when it is 0, the value is either 0 or a positive number. An 8-bit integral signed type represented using a sign-bit can hold values from 128 through 127.
琛ㄧず signed 鏁村瀷綾誨瀷鏈甯歌鐨勭瓥鐣ユ槸鐢ㄥ叾涓竴涓綅浣滀負(fù)絎﹀彿浣嶃傜鍙蜂綅涓?1錛屽煎氨涓鴻礋鏁幫紱絎﹀彿浣嶄負(fù) 0錛屽煎氨涓?0 鎴栨鏁般備竴涓?signed 鏁村瀷鍙栧兼槸浠?-128 鍒?127銆?/p>
Assignment to Integral Types
鏁村瀷鐨勮祴鍊?/h5>
The type of an object determines the values that the object can hold. This fact raises the question of what happens when one tries to assign a value outside the allowable range to an object of a given type. The answer depends on whether the type is signed or unsigned.
瀵硅薄鐨勭被鍨嬪喅瀹氬璞＄殑鍙栧箋傝繖浼?xì)寮曡捣涓涓枒闂細(xì)褰撴垜浠瘯鐫鎶婁竴涓秴鍑哄叾鍙栧艱寖鍥寸殑鍊艱祴緇欎竴涓寚瀹氱被鍨嬬殑瀵硅薄鏃訛紝緇撴灉浼?xì)鎬庢牱鍛紵絳旀鍙栧喅浜庤繖縐嶇被鍨嬫槸 signed 榪樻槸 unsigned 鐨勩?/p>
For unsigned types, the compiler must adjust the out-of-range value so that it will fit. The compiler does so by taking the remainder of the value modulo the number of distinct values the unsigned target type can hold. An object that is an 8-bit unsigned char, for example, can hold values from 0 through 255 inclusive. If we assign a value outside this range, the compiler actually assigns the remainder of the value modulo 256. For example, we might attempt to assign the value 336 to an 8-bit signed char. If we try to store 336 in our 8-bit unsigned char, the actual value assigned will be 80, because 80 is equal to 336 modulo 256.
瀵逛簬 unsigned 綾誨瀷鏉ヨ錛岀紪璇戝櫒蹇呴』璋冩暣瓚婄晫鍊間嬌鍏舵弧瓚寵姹傘傜紪璇戝櫒浼?xì)灏嗚鍊煎 unsigned 綾誨瀷鐨勫彲鑳藉彇鍊兼暟鐩眰妯★紝鐒跺悗鍙栨墍寰楀箋傛瘮濡?8 浣嶇殑 unsigned char錛屽叾鍙栧艱寖鍥翠粠 0 鍒? 255錛堝寘鎷?255錛夈傚鏋滆祴緇欒秴鍑?guó)櫩欎釜鑼冨洿鐨勫鹼紝閭ｄ箞緙栬瘧鍣ㄥ皢浼?xì)鍙栬鍊煎 256 姹傛ā鍚庣殑鍊箋備緥濡傦紝濡傛灉璇曞浘灝?336 瀛樺偍鍒?8 浣嶇殑 unsigned char 涓紝鍒欏疄闄呰祴鍊間負(fù) 80錛屽洜涓?80 鏄?336 瀵?256 姹傛ā鍚庣殑鍊箋?/p>
For the unsigned types, a negative value is always out of range. An object of unsigned type may never hold a negative value. Some languages make it illegal to assign a negative value to an unsigned type, but C++ does not.
瀵逛簬 unsigned 綾誨瀷鏉ヨ錛岃礋鏁版繪槸瓚呭嚭鍏跺彇鍊艱寖鍥淬?tt>unsigned 綾誨瀷鐨勫璞″彲鑳芥案榪滀笉浼?xì)淇濆瓨璐熸暟銆傛湁浜涜璦涓皢璐熸暟璧嬬粰 unsigned 綾誨瀷鏄潪娉曠殑錛屼絾鍦?C++ 涓繖鏄悎娉曠殑銆?/p>
|
In C++ it is perfectly legal to assign a negative number to an object with unsigned type. The result is the negative value modulo the size of the type. So, if we assign 1 to an 8-bit unsigned char, the resulting value will be 255, which is 1 modulo 256. C++ 涓紝鎶婅礋鍊艱祴緇?unsigned 瀵硅薄鏄畬鍏ㄥ悎娉曠殑錛屽叾緇撴灉鏄璐熸暟瀵硅綾誨瀷鐨勫彇鍊間釜鏁版眰妯″悗鐨勫箋傛墍浠ワ紝濡傛灉鎶?-1 璧嬬粰8浣嶇殑 unsigned char錛岄偅涔堢粨鏋滄槸 255錛屽洜涓?255 鏄?-1 瀵?256 姹傛ā鍚庣殑鍊箋?/p> |
When assigning an out-of-range value to a signed type, it is up to the compiler to decide what value to assign. In practice, many compilers treat signed types similarly to how they are required to treat unsigned types. That is, they do the assignment as the remainder modulo the size of the type. However, we are not guaranteed that the compiler will do so for the signed types.
褰撳皢瓚呰繃鍙栧艱寖鍥寸殑鍊艱祴緇?signed 綾誨瀷鏃訛紝鐢辯紪璇戝櫒鍐沖畾瀹為檯璧嬬殑鍊箋傚湪瀹為檯鎿嶄綔涓紝寰堝鐨勭紪璇戝櫒澶勭悊 signed 綾誨瀷鐨勬柟寮忓拰 unsigned 綾誨瀷綾諱技銆備篃灝辨槸璇達(dá)紝璧嬪兼椂鏄彇璇ュ煎璇ョ被鍨嬪彇鍊兼暟鐩眰妯″悗鐨勫箋傜劧鑰屾垜浠笉鑳戒繚璇佺紪璇戝櫒閮戒細(xì)榪欐牱澶勭悊 signed 綾誨瀷銆?/p>
浠ヤ笂鎽樿嚜 c++ primer,鎯劎錛岃繕鏄啀緇嗙粏鐨勪粠澶村搧涓嬈¤繖涔﹀惂銆?br>
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begin
---do
end
澶ч儴鍒嗘椂闂存垜浠敤IN 錛孨OT IN鍦╓HERE瀛愬彞閲岋紝榪欐牱鐩存帴鐢ㄥソ涔堬紝鏈変粈涔堥棶棰橈紝嬈㈣繋璁ㄨ
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1銆丄SCII()
榪斿洖瀛楃琛ㄨ揪寮忔渶宸︾瀛楃鐨凙SCII 鐮佸箋傚湪ASCII錛堬級(jí)鍑芥暟涓紝綰暟瀛楃殑瀛楃涓插彲涓嶇敤‘’鎷搗鏉ワ紝浣嗗惈鍏跺畠瀛楃鐨勫瓧絎︿覆蹇呴』鐢?#8216;’鎷搗鏉ヤ嬌鐢紝鍚﹀垯浼?xì)鍑洪敊銆?/span>
2銆丆HAR()
灝咥SCII 鐮佽漿鎹負(fù)瀛楃銆傚鏋滄病鏈夎緭鍏? ~ 255 涔嬮棿鐨凙SCII 鐮佸鹼紝CHAR錛堬級(jí) 榪斿洖NULL 銆?/span>
3銆丩OWER()鍜孶PPER()
LOWER()灝嗗瓧絎︿覆鍏ㄩ儴杞負(fù)灝忓啓錛沀PPER()灝嗗瓧絎︿覆鍏ㄩ儴杞負(fù)澶у啓銆?/span>
4銆丼TR()
鎶婃暟鍊煎瀷鏁版嵁杞崲涓哄瓧絎﹀瀷鏁版嵁銆?/span>
STR (<float_expression>[錛宭ength[錛?<decimal>]])
length 鎸囧畾榪斿洖鐨勫瓧絎︿覆鐨勯暱搴︼紝decimal 鎸囧畾榪斿洖鐨勫皬鏁頒綅鏁般傚鏋滄病鏈夋寚瀹氶暱搴︼紝緙虹渷鐨刲ength 鍊間負(fù)10錛?decimal 緙虹渷鍊間負(fù)0銆?/span>
褰搇ength 鎴栬卍ecimal 涓鴻礋鍊兼椂錛岃繑鍥濶ULL錛?/span>
褰搇ength 灝忎簬灝忔暟鐐瑰乏杈癸紙鍖呮嫭絎﹀彿浣嶏級(jí)鐨勪綅鏁版椂錛岃繑鍥瀕ength 涓?錛?/span>
鍏堟湇浠巐ength 錛屽啀鍙杁ecimal 錛?/span>
褰撹繑鍥炵殑瀛楃涓蹭綅鏁板皬浜巐ength 錛屽乏杈硅ˉ瓚崇┖鏍箋?/span>
浜屻佸幓絀烘牸鍑芥暟
1銆丩TRIM() 鎶婂瓧絎︿覆澶撮儴鐨勭┖鏍煎幓鎺夈?/span>
2銆丷TRIM() 鎶婂瓧絎︿覆灝鵑儴鐨勭┖鏍煎幓鎺夈?/span>
涓夈佸彇瀛愪覆鍑芥暟
1銆乴eft()
LEFT (<character_expression>錛?<integer_expression>)
榪斿洖character_expression 宸﹁搗 integer_expression 涓瓧絎︺?/span>
2銆丷IGHT()
RIGHT (<character_expression>錛?<integer_expression>)
榪斿洖character_expression 鍙寵搗 integer_expression 涓瓧絎︺?/span>
3銆丼UBSTRING()
SUBSTRING (<expression>錛?<starting_ position>錛?length)
榪斿洖浠庡瓧絎︿覆宸﹁竟絎瑂tarting_ position 涓瓧絎﹁搗length涓瓧絎︾殑閮ㄥ垎銆?/span>
鍥涖佸瓧絎︿覆姣旇緝鍑芥暟
1銆丆HARINDEX()
榪斿洖瀛楃涓蹭腑鏌愪釜鎸囧畾鐨勫瓙涓插嚭鐜扮殑寮濮嬩綅緗?/span>
CHARINDEX (<’substring_expression’>錛?<expression>)
鍏朵腑substring _expression 鏄墍瑕佹煡鎵劇殑瀛楃琛ㄨ揪寮忥紝expression 鍙負(fù)瀛楃涓蹭篃鍙負(fù)鍒楀悕琛ㄨ揪寮忋傚鏋滄病鏈夊彂鐜板瓙涓詫紝鍒欒繑鍥? 鍊箋?/span>
姝ゅ嚱鏁頒笉鑳界敤浜嶵EXT 鍜孖MAGE 鏁版嵁綾誨瀷銆?/span>
2銆丳ATINDEX()
榪斿洖瀛楃涓蹭腑鏌愪釜鎸囧畾鐨勫瓙涓插嚭鐜扮殑寮濮嬩綅緗?/span>
PATINDEX (<’%substring _expression%’>錛?<column_ name>)鍏朵腑瀛愪覆琛ㄨ揪寮忓墠鍚庡繀欏繪湁鐧懼垎鍙?#8220;%”鍚﹀垯榪斿洖鍊間負(fù)0銆?/span>
涓嶤HARINDEX 鍑芥暟涓嶅悓鐨勬槸錛孭ATINDEX鍑芥暟鐨勫瓙涓蹭腑鍙互浣跨敤閫氶厤絎︼紝涓旀鍑芥暟鍙敤浜嶤HAR銆?VARCHAR 鍜孴EXT 鏁版嵁綾誨瀷銆?/span>
浜斻佸瓧絎︿覆鎿嶄綔鍑芥暟
1銆丵UOTENAME()
榪斿洖琚壒瀹氬瓧絎︽嫭璧鋒潵鐨勫瓧絎︿覆銆?/span>
QUOTENAME (<’character_expression’>[錛?quote_ character]) 鍏朵腑quote_ character 鏍囨槑鎷瓧絎︿覆鎵鐢ㄧ殑瀛楃錛岀己鐪佸間負(fù)“[]”銆?/span>
2銆丷EPLICATE()
榪斿洖涓涓噸澶峜haracter_expression 鎸囧畾嬈℃暟鐨勫瓧絎︿覆銆?/span>
REPLICATE (character_expression integer_expression) 濡傛灉integer_expression 鍊間負(fù)璐熷鹼紝鍒欒繑鍥濶ULL 銆?/span>
3銆丷EVERSE()
灝嗘寚瀹氱殑瀛楃涓茬殑瀛楃鎺掑垪欏哄簭棰犲掋?/span>
REVERSE (<character_expression>) 鍏朵腑character_expression 鍙互鏄瓧絎︿覆銆佸父鏁版垨涓涓垪鐨勫箋?/span>
4銆丷EPLACE()
榪斿洖琚浛鎹簡(jiǎn)鎸囧畾瀛愪覆鐨勫瓧絎︿覆銆?/span>
REPLACE (<string_expression1>錛?<string_expression2>錛?<string_expression3>) 鐢╯tring_expression3 鏇挎崲鍦╯tring_expression1 涓殑瀛愪覆string_expression2銆?/span>
4銆丼PACE()
榪斿洖涓涓湁鎸囧畾闀垮害鐨勭┖鐧藉瓧絎︿覆銆?/span>
SPACE (<integer_expression>) 濡傛灉integer_expression 鍊間負(fù)璐熷鹼紝鍒欒繑鍥濶ULL 銆?/span>
5銆丼TUFF()
鐢ㄥ彟涓瀛愪覆鏇挎崲瀛楃涓叉寚瀹氫綅緗侀暱搴︾殑瀛愪覆銆?/span>
STUFF (<character_expression1>錛?<start_ position>錛?<length>錛?lt;character_expression2>)
濡傛灉璧峰浣嶇疆涓鴻礋鎴栭暱搴﹀間負(fù)璐燂紝鎴栬呰搗濮嬩綅緗ぇ浜巆haracter_expression1 鐨勯暱搴︼紝鍒欒繑鍥濶ULL 鍊箋?/span>
濡傛灉length 闀垮害澶т簬character_expression1 涓?start_ position 浠ュ彸鐨勯暱搴︼紝鍒檆haracter_expression1 鍙繚鐣欓瀛楃銆?/span>
鍏佹暟鎹被鍨嬭漿鎹㈠嚱鏁?/strong>
1銆丆AST()
CAST (<expression> AS <data_ type>[ length ])
2銆丆ONVERT()
CONVERT (<data_ type>[ length ]錛?<expression> [錛?style])
1錛塪ata_type涓篠QL Server緋葷粺瀹氫箟鐨勬暟鎹被鍨嬶紝鐢ㄦ埛鑷畾涔夌殑鏁版嵁綾誨瀷涓嶈兘鍦ㄦ浣跨敤銆?/span>
2錛塴ength鐢ㄤ簬鎸囧畾鏁版嵁鐨勯暱搴︼紝緙虹渷鍊間負(fù)30銆?/span>
3錛夋妸CHAR鎴朧ARCHAR綾誨瀷杞崲涓鴻濡侷NT鎴朣AMLLINT榪欐牱鐨処NTEGER綾誨瀷銆佺粨鏋滃繀欏繪槸甯︽鍙鋒垨璐熷彿鐨勬暟鍊箋?/span>
4錛塗EXT綾誨瀷鍒癈HAR鎴朧ARCHAR綾誨瀷杞崲鏈澶氫負(fù)8000涓瓧絎︼紝鍗矯HAR鎴朧ARCHAR鏁版嵁綾誨瀷鏄渶澶ч暱搴︺?/span>
5錛塈MAGE綾誨瀷瀛樺偍鐨勬暟鎹漿鎹㈠埌BINARY鎴朧ARBINARY綾誨瀷錛屾渶澶氫負(fù)8000涓瓧絎︺?/span>
6錛夋妸鏁存暟鍊艱漿鎹負(fù)MONEY鎴朣MALLMONEY綾誨瀷錛屾寜瀹氫箟鐨勫浗瀹剁殑璐у竵鍗曚綅鏉ュ鐞嗭紝濡備漢姘戝竵銆佺編鍏冦佽嫳闀戠瓑銆?/span>
7錛塀IT綾誨瀷鐨勮漿鎹㈡妸闈為浂鍊艱漿鎹負(fù)1錛屽茍浠嶄互BIT綾誨瀷瀛樺偍銆?/span>
8錛夎瘯鍥捐漿鎹㈠埌涓嶅悓闀垮害鐨勬暟鎹被鍨嬶紝浼?xì)鎴煭铦{鎹㈠煎茍鍦ㄨ漿鎹㈠煎悗鏄劇ず“+”錛屼互鏍囪瘑鍙戠敓浜?jiǎn)杩櫩U嶆埅鏂?/span>
9錛夌敤CONVERT錛堬級(jí) 鍑芥暟鐨剆tyle 閫夐」鑳戒互涓嶅悓鐨勬牸寮忔樉紺烘棩鏈熷拰鏃墮棿銆俿tyle 鏄皢DATATIME 鍜孲MALLDATETIME 鏁版嵁杞崲涓哄瓧絎︿覆鏃舵墍閫夌敤鐨勭敱SQL Server 緋葷粺鎻愪緵鐨勮漿鎹㈡牱寮忕紪鍙鳳紝涓嶅悓鐨勬牱寮忕紪鍙鋒湁涓嶅悓鐨勮緭鍑烘牸寮忋?/span>
涓冦佹棩鏈熷嚱鏁?/strong>
1銆乨ay(date_expression)
榪斿洖date_expression涓殑鏃ユ湡鍊?/span>
2銆乵onth(date_expression)
榪斿洖date_expression涓殑鏈堜喚鍊?/span>
3銆亂ear(date_expression)
榪斿洖date_expression涓殑騫翠喚鍊?/span>
4銆丏ATEADD()
DATEADD (<datepart>錛?<number>錛?<date>)
榪斿洖鎸囧畾鏃ユ湡date 鍔犱笂鎸囧畾鐨勯澶栨棩鏈熼棿闅攏umber 浜х敓鐨勬柊鏃ユ湡銆?/span>
5銆丏ATEDIFF()
DATEDIFF (<datepart>錛?<date1>錛?<date2>)
榪斿洖涓や釜鎸囧畾鏃ユ湡鍦╠atepart 鏂歸潰鐨勪笉鍚屼箣澶勶紝鍗砫ate2 瓚呰繃date1鐨勫樊璺濆鹼紝鍏剁粨鏋滃兼槸涓涓甫鏈夋璐熷彿鐨勬暣鏁板箋?/span>
6銆丏ATENAME()
DATENAME (<datepart>錛?<date>)
浠ュ瓧絎︿覆鐨勫艦寮忚繑鍥炴棩鏈熺殑鎸囧畾閮ㄥ垎姝ら儴鍒嗐傜敱datepart 鏉ユ寚瀹氥?/span>
7銆丏ATEPART()
DATEPART (<datepart>錛?<date>)
浠ユ暣鏁板肩殑褰㈠紡榪斿洖鏃ユ湡鐨勬寚瀹氶儴鍒嗐傛閮ㄥ垎鐢眃atepart 鏉ユ寚瀹氥?/span>
DATEPART (dd錛?date) 絳夊悓浜嶥AY (date)
DATEPART (mm錛?date) 絳夊悓浜嶮ONTH (date)
DATEPART (yy錛?date) 絳夊悓浜嶻EAR (date)
8銆丟ETDATE()
浠ATETIME 鐨勭己鐪佹牸寮忚繑鍥炵郴緇熷綋鍓嶇殑鏃ユ湡鍜屾椂闂淬?/span>
]]>
adOpenForwardOnly > adOpenDynamic > adOpenKeyset > adOpenStatic
娓告爣綾誨瀷鏈変互涓嬪洓縐嶇被鍨嬶細(xì)
1銆? AdOpenForwardOnly 錛堥粯璁ゅ鹼級(jí)涓嬈″彧鑳藉悜鍓嶇Щ鍔ㄤ竴琛屻?
2銆? AdOpenKeyset 鎵撳紑閿泦綾誨瀷娓告爣銆?
3銆? AdOpenDynamic 鎵撳紑鍔ㄦ佺被鍨嬫父鏍?
4銆? AdOpenStatic 鎵撳紑闈?rùn)鎬佺被鍨嬫父鏍囥?
AdOpenForwardOnly鍜孉dOpenStatic榪欎袱縐嶆父鏍囦嬌寰楄褰曢泦鍙錛屽畠琛ㄧず鍒涘緩鏁版嵁鐨勪竴涓揩鐓с傚悗鑰呮瘮鍓嶈呯伒媧伙紝鍥犱負(fù)瀹冨彲浠ュ厑璁鎬換鎰忔柟鍚戠Щ鍔ㄣ?
AdOpenKeyset鍏佽浠繪剰縐誨姩錛屽茍涓斿厑璁告洿鏀硅褰曢泦銆傚叾浠栫敤鎴峰璁板綍闆嗙殑娣誨姞鍜屽垹闄わ紝榪欎釜娓告爣鍙嶆槧涓嶅嚭鏉ャ備絾瀹冭兘鍙嶆槧鍑哄叾浠栫敤鎴峰璁板綍闆嗙殑鏇存敼銆?
AdOpenDynamic鍏佽鎵鏈夋搷浣滐紝鍏朵粬鐢ㄦ埛瀵硅褰曢泦鐨勬坊鍔犮佸垹闄ゃ佹洿鏀瑰湪姝よ褰曢泦涓?
閮芥槸鍙鐨勩?
LockType= adLockOptimistic
Options 鐪佺暐
澶у闇瑕佹敞鎰忕殑鏄細(xì)褰撲嬌鐢ˋdOpenKeyset鏃訛紝瑕佹眰璁板綍闆嗕腑姣忔潯璁板綍閮芥湁鍞竴鐨勫叧閿瓧銆傚惁鍒欙紝鎵ц鐨勭粨鏋滃氨涓嶆槸鎮(zhèn)ㄦ墍瑕佺殑鎵鏈夎褰曚簡(jiǎn)銆?
娓呮浜?jiǎn)娓告爣绫诲瀷锛屽啀鏉ョ湅鐪嬮攣绫诲瀷LockType
AdLockReadOnly 錛堥粯璁ゅ鹼級(jí)鍙 --- 涓嶈兘鏀瑰彉鏁版嵁銆?
AdLockPessimistic 鎮(zhèn)茶閿侊紙閫愪釜錛?-- 涓虹‘淇濇垚鍔熷畬鎴愮紪杈戣褰曟墍闇鐨勫伐浣滐紝
鍦ㄧ紪杈戞椂绔嬪嵆閿佸畾鏁版嵁婧愮殑璁板綍銆?
AdLockOptimistic 涔愯閿侊紙閫愪釜錛?-- 鍙湪璋冪敤Update 鏂規(guī)硶鏃舵墠閿佸畾璁板綍銆?
AdLockBatchOptimistic 涔愯鎵規(guī)洿鏂?--鐢ㄤ簬鎵規(guī)洿鏂版ā寮忥紙涓庣珛鍗蟲(chóng)洿鏂版ā寮忕浉瀵癸級(jí)銆?
瀵逛簬鎮(zhèn)茶閿併佷箰瑙傞攣鐨勮В閲婏細(xì)
涔愯鐨勯攣絳栫暐鏄妸璁板綍蹇呴』鍔犻攣鐨勬椂闂村噺鍒版渶鐭紝褰撶敤鎴峰璁板綍鐨勫唴瀹硅繘琛岀紪杈戞椂錛屼箰瑙傞攣涓嶈搗浣滅敤錛屽叾浠栫敤鎴峰彲浠ヨ闂拰緙栬緫鏁版嵁錛屼絾褰撳叾涓殑涓涓敤鎴鋒兂瑕佹洿鏂版暟鎹椂錛岃褰曞氨浼?xì)鍔犱笂閿佸Q?
鎮(zhèn)茶鐨勯攣絳栫暐鏄綋絎竴涓敤鎴鋒墦寮璁板綍榪涜緙栬緫鐨勬椂鍊欙紝璁板綍灝變細(xì)鍔犻攣錛岀洿鍒頒嬌鐢ㄨ褰曠殑鐢ㄦ埛瑙ｉ櫎閿佹椂閿佹墠涓嶈搗浣滅敤銆備竴鏃︽?zhèn)茶閿佽捣浣滅敤锛屽叾浠栫殑鐢ㄦ埛灏辩湅涓嶅埌鏁版嵁锛岀洿鍒拌閿佽瑙ｉ櫎锛?
瀵逛簬AdLockBatchOptimistic錛屽彧鑳戒笌AdOpenKeyset娓告爣涓璧蜂嬌鐢ㄣ傚畠鍦ㄦ洿鏂版椂涓嶄細(xì)绔嬪嵆鎶婃洿鏂拌繃鐨勮褰曞啓鍏ュ埌鏁版嵁婧愪腑錛岃屾槸鎶婂璁稿鏉¤褰曟墍鍋氱殑鏀瑰姩鍏堟斁鍦ㄥ鎴瘋綆楁満涓紝鐒跺悗鎶婃洿鏂拌繃鐨勮褰曚綔涓轟竴鎵瑰啓鍏ユ暟鎹簮
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