l Dos 鐜涓嬩嬌鐢⊿Ql*Loader鍛戒護 鍔犺澆
l 浣跨敤鍏跺畠鏁版嵁搴撶殑鏁版嵁杞Щ宸ュ叿
l Oracle 浼佷笟綆＄悊鍣ㄤ腑鐨勬暟鎹姞杞藉姛鑳?/span>
鍏蜂綋鐨勬妧鏈疄鐜?/span>
涓銆?/span>Dos 鐜涓嬪姞杞?/span>
1銆侀鍏堬紝鏈嶅姟鍣ㄧ鐨勪睛鍚湇鍔″繀欏誨凡緇忓紑鍚?/span>
嫻嬭瘯鏂規硶錛?/span>Dos 涓嬭緭鍏?/span>
C:\>sqlplus username/password@serviceName
2銆佺劧鍚庝嬌鐢?/span> Oracle 鐨?/span> sqlldr 鍛戒護榪涜鏁版嵁鐨勫鍏?/span>
鍓嶆湡鏉′歡
1錛?span style="font: 7pt 'Times New Roman';"> Oracle 鏁版嵁搴撶蹇呴』宸茬粡寤哄ソ浜嗛渶瑕佸鍏ョ殑鏁版嵁琛ㄧ殑緇撴瀯
2錛?span style="font: 7pt 'Times New Roman';"> 涓涓暟鎹簮鏂囦歡 涓嬮潰渚嬪瓙涓負鍒惰〃絎﹀垎闅旂殑鏂囨湰鏂囦歡 model.txt ,涓?/span>Excel 琛ㄤ腑瀵煎嚭鐨?/span>
3錛?span style="font: 7pt 'Times New Roman';"> 鎵嬪伐緙栬緫涓涓?/span>XXX.CTL 鐨勬帶鍒舵枃浠?/span>
4錛?span style="font: 7pt 'Times New Roman';"> 鍛戒護琛屽姞杞芥暟鎹?/span>
濡備笅瀹炰緥錛?/span>
浠ヤ笅鏂囦歡緙虹渷鏀懼埌C:\ 涓嬶紝濡傛灉涓嶆槸錛屽氨闇瑕佹寚鏄庡叏璺緞
1錛?span style="font: 7pt 'Times New Roman';"> 鍛戒護鎺у埗鏂囦歡 input.ctl 鍐呭
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鍛戒護 |
璇存槑 |
|
load data |
1銆佹帶鍒舵枃浠舵爣璇?/span> |
|
infile 'model.txt'銆 |
2銆佽杈撳叆鐨勬暟鎹枃浠跺悕涓?/span>test.txt |
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append into table system.濉斾綅灞炴ц〃 |
3銆佸悜琛?/span>test涓拷鍔犺褰?/span> |
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fields terminated by X'09' |
4銆佹寚瀹氬垎闅旂錛屽瓧孌電粓姝簬X'09'錛屾槸涓涓埗琛ㄧ錛?/span>TAB錛?/span> |
|
(緙栧彿,鍚嶇О,澶у皬) |
5銆佸畾涔夊垪瀵瑰簲琛ㄤ腑欏哄簭 |
鎺у埗鏂囦歡涓寚瀹氭彃鍏ユ暟鎹殑鏂瑰紡鍏抽敭瀛?/span>
l insert錛屼負緙虹渷鏂瑰紡錛屽湪鏁版嵁瑁呰澆寮濮嬫椂瑕佹眰琛ㄤ負絀?/span>
l append錛屽湪琛ㄤ腑榪藉姞鏂拌褰?/span>
l replace錛屽垹闄ゆ棫璁板綍錛屾浛鎹㈡垚鏂拌杞界殑璁板綍
l truncate錛屽悓涓?/span>
鍦?/span> Dos 紿楀彛涓嬩嬌鐢?/span> SQl*Loader 鍛戒護瀹炵幇鏁版嵁鐨勫鍏?/span>
C:\>sqlldr userid=system/manager@ serviceName control=input.ctl
榛樿鏃ュ織鏂囦歡鍚嶄負錛?span lang="EN-US">input.log
榛樿鍧忚褰曟枃浠朵負錛?span lang="EN-US">input.bad
浜屻佷嬌鐢ㄥ叾瀹冩暟鎹簱杞Щ宸ュ叿
浠ヤ笅浠?/span>SQL Server 瀵煎叆瀵煎嚭鍚戝涓轟緥
1銆佸湪鏁版嵁鐨勫鍏ュ鍑哄悜瀵間腑璁劇疆鏁版嵁婧愭湇鍔″櫒錛屽疄渚嬩腑閫夋嫨鏁版嵁婧愰夋嫨SQL Server
2銆佺劧鍚庢寚瀹氳瀵煎叆鐨?/span>Oracle 鏁版嵁婧?/span>
3銆侀渶瑕侀厤緗?/span>Oracle 鐨勫睘鎬т俊鎭?/span>
闇瑕佹敞鎰忕殑鏄紝鐧誨綍鏁版嵁搴撶殑鐢ㄦ埛淇℃伅鍗充負鏁版嵁瀵煎叆涔嬪悗鐨勬柟妗堝悕錛屽嵆瀵煎叆涔嬪悗鐨?/span>SQL Server 涓殑琛ㄥ湪Oracle 涓爣蹇楀悕涓?/span> username.琛ㄥ悕
浠ヤ笅鎸夌収鎻愮ず鍗沖彲錛屽彲浠ュ畬鍏ㄥ鍏?/span>SQl Server 涓殑鏁版嵁琛ㄥ拰瑙嗗浘錛屼篃鍙互浣跨敤鏌ヨ璇彞榪斿洖浣犺閫夋嫨鐨勫垪鎴栬呰銆?/span>
涓夈?span style="font: 7pt 'Times New Roman';"> Oracle 浼佷笟綆＄悊鍣ㄤ腑鐨勬暟鎹姞杞藉姛鑳?/span>
鐧誨綍Oracle 鐨勬帶鍒跺彴鐣岄潰錛岄拡瀵瑰崟鐙殑鏁版嵁琛ㄥ彲浠ヤ嬌鐢ㄦ暟鎹姞杞藉伐鍏?/span>
涓棿闇瑕佹寚瀹氭帶鍒舵枃浠剁瓑錛屽悓Dos 鍔犺澆涓鑷達紝涓嶅啀閲嶅
]]>
濡傦細
select to_char(name),price from aa
union all
select to_char(name),price from bb
3寮犺〃aa,bb,cc閮芥湁 name price 瀛楁 鏌ヨ浠鋒牸鏈楂樼殑鍓?浣嶅鍚?br />
select * from(select to_char(name),price from aa
union all
select to_char(name),price from bb
union all
select to_char(name),price from cc order by price desc)where rownum<=3
]]>
Oracle鐨勮В鏋愬櫒鎸夌収浠庡彸鍒板乏鐨勯『搴忓鐞咶ROM瀛愬彞涓殑琛ㄥ悕錛孎ROM瀛愬彞涓啓鍦ㄦ渶鍚庣殑琛?鍩虹琛?driving table)灝嗚鏈鍏堝鐞嗭紝鍦‵ROM瀛愬彞涓寘鍚涓〃鐨勬儏鍐典笅,浣犲繀欏婚夋嫨璁板綍鏉℃暟鏈灝戠殑琛ㄤ綔涓哄熀紜琛ㄣ傚亣濡傛湁3涓互涓婄殑琛ㄨ繛鎺ユ煡璇? 閭ｅ氨闇瑕侀夋嫨浜ゅ弶琛?intersection table)浣滀負鍩虹琛? 浜ゅ弶琛ㄦ槸鎸囬偅涓鍏朵粬琛ㄦ墍寮曠敤鐨勮〃.
錛?錛?WHERE瀛愬彞涓殑榪炴帴欏哄簭錛庯細
ORACLE閲囩敤鑷笅鑰屼笂鐨勯『搴忚В鏋怶HERE瀛愬彞,鏍規嵁榪欎釜鍘熺悊,琛ㄤ箣闂寸殑榪炴帴蹇呴』鍐欏湪鍏朵粬WHERE鏉′歡涔嬪墠, 閭ｄ簺鍙互榪囨護鎺夋渶澶ф暟閲忚褰曠殑鏉′歡蹇呴』鍐欏湪WHERE瀛愬彞鐨勬湯灝?
錛?錛?SELECT瀛愬彞涓伩鍏嶄嬌鐢?‘ * ‘錛?
ORACLE鍦ㄨВ鏋愮殑榪囩▼涓? 浼氬皢'*' 渚濇杞崲鎴愭墍鏈夌殑鍒楀悕, 榪欎釜宸ヤ綔鏄氳繃鏌ヨ鏁版嵁瀛楀吀瀹屾垚鐨? 榪欐剰鍛崇潃灝嗚楄垂鏇村鐨勬椂闂?
錛?錛?鍑忓皯璁塊棶鏁版嵁搴撶殑嬈℃暟錛?
ORACLE鍦ㄥ唴閮ㄦ墽琛屼簡璁稿宸ヤ綔: 瑙ｆ瀽SQL璇彞, 浼扮畻绱㈠紩鐨勫埄鐢ㄧ巼, 緇戝畾鍙橀噺 , 璇繪暟鎹潡絳夛紱
錛?錛?鍦⊿QL*Plus , SQL*Forms鍜孭ro*C涓噸鏂拌緗瓵RRAYSIZE鍙傛暟, 鍙互澧炲姞姣忔鏁版嵁搴撹闂殑媯绱㈡暟鎹噺 ,寤鴻鍊間負200
錛?錛?浣跨敤DECODE鍑芥暟鏉ュ噺灝戝鐞嗘椂闂達細
浣跨敤DECODE鍑芥暟鍙互閬垮厤閲嶅鎵弿鐩稿悓璁板綍鎴栭噸澶嶈繛鎺ョ浉鍚岀殑琛?
錛?錛?鏁村悎綆鍗?鏃犲叧鑱旂殑鏁版嵁搴撹闂細
鍋囧浣犳湁鍑犱釜綆鍗曠殑鏁版嵁搴撴煡璇㈣鍙?浣犲彲浠ユ妸瀹冧滑鏁村悎鍒頒竴涓煡璇腑(鍗充嬌瀹冧滑涔嬮棿娌℃湁鍏崇郴)
錛?錛?鍒犻櫎閲嶅璁板綍錛?
鏈楂樻晥鐨勫垹闄ら噸澶嶈褰曟柟娉?( 鍥犱負浣跨敤浜哛OWID)渚嬪瓙錛?
DELETE FROM EMP E WHERE E.ROWID > (SELECT MIN(X.ROWID)
FROM EMP X WHERE X.EMP_NO = E.EMP_NO);
錛?錛?鐢═RUNCATE鏇夸唬DELETE錛?
褰撳垹闄よ〃涓殑璁板綍鏃?鍦ㄩ氬父鎯呭喌涓? 鍥炴粴孌?rollback segments ) 鐢ㄦ潵瀛樻斁鍙互琚仮澶嶇殑淇℃伅. 鍋囧浣犳病鏈塁OMMIT浜嬪姟,ORACLE浼氬皢鏁版嵁鎭㈠鍒板垹闄や箣鍓嶇殑鐘舵?鍑嗙‘鍦拌鏄仮澶嶅埌鎵ц鍒犻櫎鍛戒護涔嬪墠鐨勭姸鍐? 鑰屽綋榪愮敤TRUNCATE鏃? 鍥炴粴孌典笉鍐嶅瓨鏀句換浣曞彲琚仮澶嶇殑淇℃伅.褰撳懡浠よ繍琛屽悗,鏁版嵁涓嶈兘琚仮澶?鍥犳寰堝皯鐨勮祫婧愯璋冪敤,鎵ц鏃墮棿涔熶細寰堢煭. (璇戣呮寜: TRUNCATE鍙湪鍒犻櫎鍏ㄨ〃閫傜敤,TRUNCATE鏄疍DL涓嶆槸DML)
錛?0錛?灝介噺澶氫嬌鐢–OMMIT錛?
鍙鏈夊彲鑳?鍦ㄧ▼搴忎腑灝介噺澶氫嬌鐢–OMMIT, 榪欐牱紼嬪簭鐨勬ц兘寰楀埌鎻愰珮,闇姹備篃浼氬洜涓篊OMMIT鎵閲婃斁鐨勮祫婧愯屽噺灝?
COMMIT鎵閲婃斁鐨勮祫婧?
a. 鍥炴粴孌典笂鐢ㄤ簬鎭㈠鏁版嵁鐨勪俊鎭?
b. 琚▼搴忚鍙ヨ幏寰楃殑閿?
c. redo log buffer 涓殑絀洪棿
d. ORACLE涓烘不鐞嗕笂榪?縐嶈祫婧愪腑鐨勫唴閮ㄨ姳璐?
錛?1錛?鐢╓here瀛愬彞鏇挎崲HAVING瀛愬彞錛?
閬垮厤浣跨敤HAVING瀛愬彞, HAVING 鍙細鍦ㄦ绱㈠嚭鎵鏈夎褰曚箣鍚庢墠瀵圭粨鏋滈泦榪涜榪囨護. 榪欎釜澶勭悊闇瑕佹帓搴?鎬昏絳夋搷浣? 鍋囧鑳介氳繃WHERE瀛愬彞闄愬埗璁板綍鐨勬暟鐩?閭ｅ氨鑳藉噺灝戣繖鏂歸潰鐨勫紑閿. (闈瀘racle涓?on銆亀here銆乭aving榪欎笁涓兘鍙互鍔犳潯浠剁殑瀛愬彞涓紝on鏄渶鍏堟墽琛岋紝where嬈′箣錛宧aving鏈鍚庯紝鍥犱負on鏄厛鎶婁笉絎﹀悎鏉′歡鐨勮褰曡繃婊ゅ悗鎵嶈繘琛岀粺璁★紝瀹冨氨鍙互鍑忓皯涓棿榪愮畻瑕佸鐞嗙殑鏁版嵁錛屾寜鐞嗚搴旇閫熷害鏄渶蹇殑錛寃here涔熷簲璇ユ瘮having蹇偣鐨勶紝鍥犱負瀹冭繃婊ゆ暟鎹悗鎵嶈繘琛宻um錛屽湪涓や釜琛ㄨ仈鎺ユ椂鎵嶇敤on鐨勶紝鎵浠ュ湪涓涓〃鐨勬椂鍊欙紝灝卞墿涓媤here璺焗aving姣旇緝浜嗐傚湪榪欏崟琛ㄦ煡璇㈢粺璁＄殑鎯呭喌涓嬶紝鍋囧瑕佽繃婊ょ殑鏉′歡娌℃湁娑夊強鍒拌璁＄畻瀛楁錛岄偅瀹冧滑鐨勭粨鏋滄槸涓鏍風殑錛屽彧鏄痺here鍙互浣跨敤rushmore鎶鏈紝鑰宧aving灝變笉鑳斤紝鍦ㄩ熷害涓婂悗鑰呰鎱㈠亣濡傝娑夊強鍒拌綆楃殑瀛楁錛屽氨琛ㄧず鍦ㄦ病璁＄畻涔嬪墠錛岃繖涓瓧孌電殑鍊兼槸涓嶇‘瀹氱殑錛屾牴鎹笂綃囧啓鐨勫伐浣滄祦紼嬶紝where鐨勪綔鐢ㄦ椂闂存槸鍦ㄨ綆椾箣鍓嶅氨瀹屾垚鐨勶紝鑰宧aving灝辨槸鍦ㄨ綆楀悗鎵嶈搗浣滅敤鐨勶紝鎵浠ュ湪榪欑鎯呭喌涓嬶紝涓よ呯殑緇撴灉浼氫笉鍚屻傚湪澶氳〃鑱旀帴鏌ヨ鏃訛紝on姣攚here鏇存棭璧蜂綔鐢ㄣ傜郴緇熼鍏堟牴鎹悇涓〃涔嬮棿鐨勮仈鎺ユ潯浠訛紝鎶婂涓〃鍚堟垚涓涓復鏃惰〃鍚庯紝鍐嶇敱where榪涜榪囨護錛岀劧鍚庡啀璁＄畻錛岃綆楀畬鍚庡啀鐢県aving榪涜榪囨護銆傜敱姝ゅ彲瑙侊紝瑕佹兂榪囨護鏉′歡璧峰埌姝ｇ‘鐨勪綔鐢紝棣栧厛瑕佹槑鐧借繖涓潯浠跺簲璇ュ湪浠涔堟椂鍊欒搗浣滅敤錛岀劧鍚庡啀鍐沖畾鏀懼湪閭ｉ噷
錛?2錛?鍑忓皯瀵硅〃鐨勬煡璇細
鍦ㄥ惈鏈夊瓙鏌ヨ鐨凷QL璇彞涓?瑕侀潪鍑℃敞閲嶅噺灝戝琛ㄧ殑鏌ヨ.渚嬪瓙錛?
SELECT TAB_NAME FROM TABLES WHERE (TAB_NAME,DB_VER) = ( SELECT
TAB_NAME,DB_VER FROM TAB_COLUMNS WHERE VERSION = 604)
錛?3錛?閫氳繃鍐呴儴鍑芥暟鎻愰珮SQL鏁堢巼.錛?
澶嶆潅鐨凷QL寰寰鐗虹壊浜嗘墽琛屾晥鐜? 鑳藉鎶婃彙涓婇潰鐨勮繍鐢ㄥ嚱鏁拌В鍐抽棶棰樼殑鏂規硶鍦ㄥ疄闄呭伐浣滀腑鏄潪甯告湁鎰忎箟鐨?
錛?4錛?浣跨敤琛ㄧ殑鍒悕(Alias)錛?
褰撳湪SQL璇彞涓繛鎺ュ涓〃鏃? 璇蜂嬌鐢ㄨ〃鐨勫埆鍚嶅茍鎶婂埆鍚嶅墠緙浜庢瘡涓狢olumn涓?榪欐牱涓鏉?灝卞彲浠ュ噺灝戣В鏋愮殑鏃墮棿騫跺噺灝戦偅浜涚敱Column姝т箟寮曡搗鐨勮娉曢敊璇?
錛?5錛?鐢‥XISTS鏇夸唬IN銆佺敤NOT EXISTS鏇夸唬NOT IN錛?
鍦ㄨ澶氬熀浜庡熀紜琛ㄧ殑鏌ヨ涓?涓轟簡婊¤凍涓涓潯浠?寰寰闇瑕佸鍙︿竴涓〃榪涜鑱旀帴.鍦ㄨ繖縐嶆儏鍐典笅, 浣跨敤EXISTS(鎴朜OT EXISTS)閫氬父灝嗘彁楂樻煡璇㈢殑鏁堢巼. 鍦ㄥ瓙鏌ヨ涓?NOT IN瀛愬彞灝嗘墽琛屼竴涓唴閮ㄧ殑鎺掑簭鍜屽悎騫? 鏃犺鍦ㄥ摢縐嶆儏鍐典笅,NOT IN閮芥槸鏈浣庢晥鐨?(鍥犱負瀹冨瀛愭煡璇腑鐨勮〃鎵ц浜嗕竴涓叏琛ㄩ亶鍘?. 涓轟簡閬垮厤浣跨敤NOT IN ,鎴戜滑鍙互鎶婂畠鏀瑰啓鎴愬榪炴帴(Outer Joins)鎴朜OT EXISTS.
渚嬪瓙錛?
錛堥珮鏁堬級SELECT * FROM EMP (鍩虹琛? WHERE EMPNO > 0 AND EXISTS (SELECT ‘X' FROM DEPT WHERE DEPT.DEPTNO = EMP.DEPTNO AND LOC = ‘MELB')
(浣庢晥)SELECT * FROM EMP (鍩虹琛? WHERE EMPNO > 0 AND DEPTNO IN(SELECT DEPTNO FROM DEPT WHERE LOC = ‘MELB')
錛?6錛?璇嗗埆'浣庢晥鎵ц'鐨凷QL璇彞錛?
铏界劧鐩墠鍚勭鍏充簬SQL浼樺寲鐨勫浘褰㈠寲宸ュ叿灞傚嚭涓嶇┓,浣嗘槸鍐欏嚭鑷繁鐨凷QL宸ュ叿鏉ヨВ鍐抽棶棰樺緇堟槸涓涓渶濂界殑鏂規硶錛?
SELECT EXECUTIONS , DISK_READS, BUFFER_GETS, ROUND((BUFFER_GETS-DISK_READS)/BUFFER_GETS,2) Hit_radio, ROUND(DISK_READS/EXECUTIONS,2) Reads_per_run,
SQL_TEXT FROM V$SQLAREA WHERE EXECUTIONS>0 AND BUFFER_GETS > 0 AND (BUFFER_GETS-DISK_READS)/BUFFER_GETS < 0.8 ORDER BY 4 DESC;
錛?7錛?鐢ㄧ儲寮曟彁楂樻晥鐜囷細
绱㈠紩鏄〃鐨勪竴涓蹇甸儴鍒?鐢ㄦ潵鎻愰珮媯绱㈡暟鎹殑鏁堢巼錛孫RACLE浣跨敤浜嗕竴涓鏉傜殑鑷鉤琛-tree緇撴瀯. 閫氬父,閫氳繃绱㈠紩鏌ヨ鏁版嵁姣斿叏琛ㄦ壂鎻忚蹇? 褰揙RACLE鎵懼嚭鎵ц鏌ヨ鍜孶pdate璇彞鐨勬渶浣寵礬寰勬椂, ORACLE浼樺寲鍣ㄥ皢浣跨敤绱㈠紩. 鍚屾牱鍦ㄨ仈緇撳涓〃鏃朵嬌鐢ㄧ儲寮曚篃鍙互鎻愰珮鏁堢巼. 鍙︿竴涓嬌鐢ㄧ儲寮曠殑濂藉鏄?瀹冩彁渚涗簡涓婚敭(primary key)鐨勫敮涓鎬ч獙璇?銆傞偅浜汱ONG鎴朙ONG RAW鏁版嵁綾誨瀷, 浣犲彲浠ョ儲寮曞嚑涔庢墍鏈夌殑鍒? 閫氬父, 鍦ㄥぇ鍨嬭〃涓嬌鐢ㄧ儲寮曢潪鍑℃湁鏁? 褰撶劧,浣犱篃浼氬彂鐜? 鍦ㄦ壂鎻忓皬琛ㄦ椂,浣跨敤绱㈠紩鍚屾牱鑳芥彁楂樻晥鐜? 铏界劧浣跨敤绱㈠紩鑳藉緱鍒版煡璇㈡晥鐜囩殑鎻愰珮,浣嗘槸鎴戜滑涔熷繀欏繪敞閲嶅埌瀹冪殑浠ｄ環. 绱㈠紩闇瑕佺┖闂存潵瀛樺偍,涔熼渶瑕佸畾鏈熺淮鎶? 姣忓綋鏈夎褰曞湪琛ㄤ腑澧炲噺鎴栫儲寮曞垪琚慨鏀規椂, 绱㈠紩鏈韓涔熶細琚慨鏀? 榪欐剰鍛崇潃姣忔潯璁板綍鐨処NSERT , DELETE , UPDATE灝嗕負姝ゅ浠樺嚭4 , 5 嬈＄殑紓佺洏I/O . 鍥犱負绱㈠紩闇瑕侀澶栫殑瀛樺偍絀洪棿鍜屽鐞?閭ｄ簺涓嶅繀瑕佺殑绱㈠紩鍙嶈屼細浣挎煡璇㈠弽搴旀椂闂村彉鎱?銆傚畾鏈熺殑閲嶆瀯绱㈠紩鏄湁蹇呰鐨?錛?
ALTER INDEX <INDEXNAME> REBUILD <TABLESPACENAME>
錛?8錛?鐢‥XISTS鏇挎崲DISTINCT錛?
褰撴彁浜や竴涓寘鍚竴瀵瑰琛ㄤ俊鎭?姣斿閮ㄩ棬琛ㄥ拰闆囧憳琛?鐨勬煡璇㈡椂,閬垮厤鍦⊿ELECT瀛愬彞涓嬌鐢―ISTINCT. 涓鑸彲浠ヨ冭檻鐢‥XIST鏇挎崲, EXISTS 浣挎煡璇㈡洿涓鴻繀閫?鍥犱負RDBMS鏍稿績妯″潡灝嗗湪瀛愭煡璇㈢殑鏉′歡涓鏃︽弧瓚沖悗,椹笂榪斿洖緇撴灉. 渚嬪瓙錛?
(浣庢晥): SELECT DISTINCT DEPT_NO,DEPT_NAME FROM DEPT D , EMP E
WHERE D.DEPT_NO = E.DEPT_NO (楂樻晥): SELECT DEPT_NO,DEPT_NAME FROM DEPT D WHERE EXISTS ( SELECT ‘X' FROM EMP E WHERE E.DEPT_NO = D.DEPT_NO);
錛?9錛?sql璇彞鐢ㄥぇ鍐欑殑錛涘洜涓簅racle鎬繪槸鍏堣В鏋恠ql璇彞錛屾妸灝忓啓鐨勫瓧姣嶈漿鎹㈡垚澶у啓鐨勫啀鎵ц
錛?0錛?鍦↗ava浠ｇ爜涓敖閲忓皯鐢ㄨ繛鎺ョ“錛?#8221;榪炴帴瀛楃涓詫紒
錛?1錛?閬垮厤鍦ㄧ儲寮曞垪涓婁嬌鐢∟OT 閫氬父錛屻
鎴戜滑瑕侀伩鍏嶅湪绱㈠紩鍒椾笂浣跨敤NOT, NOT浼氫駭鐢熷湪鍜屽湪绱㈠紩鍒椾笂浣跨敤鍑芥暟鐩稿悓鐨勫獎鍝? 褰揙RACLE”紕板埌”NOT,浠栧氨浼氬仠姝嬌鐢ㄧ儲寮曡漿鑰屾墽琛屽叏琛ㄦ壂鎻?
錛?2錛?閬垮厤鍦ㄧ儲寮曞垪涓婁嬌鐢ㄨ綆楋紟
WHERE瀛愬彞涓紝鍋囧绱㈠紩鍒楁槸鍑芥暟鐨勪竴閮ㄥ垎錛庝紭鍖栧櫒灝嗕笉浣跨敤绱㈠紩鑰屼嬌鐢ㄥ叏琛ㄦ壂鎻忥紟 涓句緥: 浣庢晥錛?
SELECT … FROM DEPT WHERE SAL * 12 > 25000; 楂樻晥: SELECT … FROM DEPT WHERE SAL > 25000/12;
錛?3錛?鐢?gt;=鏇夸唬>
楂樻晥:
SELECT * FROM EMP WHERE DEPTNO >=4 浣庢晥:
SELECT * FROM EMP WHERE DEPTNO >3 涓よ呯殑鍖哄埆鍦ㄤ簬, 鍓嶈匘BMS灝嗙洿鎺ヨ煩鍒扮涓涓狣EPT絳変簬4鐨勮褰曡屽悗鑰呭皢棣栧厛瀹氫綅鍒癉EPTNO=3鐨勮褰曞茍涓斿悜鍓嶆壂鎻忓埌絎竴涓狣EPT澶т簬3鐨勮褰?
錛?4錛?鐢║NION鏇挎崲OR (閫傜敤浜庣儲寮曞垪)
閫氬父鎯呭喌涓? 鐢║NION鏇挎崲WHERE瀛愬彞涓殑OR灝嗕細璧峰埌杈冨ソ鐨勬晥鏋? 瀵圭儲寮曞垪浣跨敤OR灝嗛犳垚鍏ㄨ〃鎵弿. 娉ㄩ噸, 浠ヤ笂瑙勫垯鍙拡瀵瑰涓儲寮曞垪鏈夋晥. 鍋囧鏈塩olumn娌℃湁琚儲寮? 鏌ヨ鏁堢巼鍙兘浼氬洜涓轟綘娌℃湁閫夋嫨OR鑰岄檷浣? 鍦ㄤ笅闈㈢殑渚嬪瓙涓? LOC_ID 鍜孯EGION涓婇兘寤烘湁绱㈠紩. 楂樻晥: SELECT LOC_ID , LOC_DESC , REGION FROM LOCATION WHERE LOC_ID = 10 UNION SELECT LOC_ID , LOC_DESC , REGION FROM LOCATION WHERE REGION = “MELBOURNE” 浣庢晥: SELECT LOC_ID , LOC_DESC , REGION FROM LOCATION WHERE LOC_ID = 10 OR REGION = “MELBOURNE” 鍋囧浣犲潥鎸佽鐢∣R, 閭ｅ氨闇瑕佽繑鍥炶褰曟渶灝戠殑绱㈠紩鍒楀啓鍦ㄦ渶鍓嶉潰.
錛?5錛?鐢↖N鏉ユ浛鎹R
榪欐槸涓鏉＄畝鍗曟槗璁扮殑瑙勫垯錛屼絾鏄疄闄呯殑鎵ц鏁堟灉榪橀』媯楠岋紝鍦∣RACLE8i涓嬶紝涓よ呯殑鎵ц璺緞浼間箮鏄浉鍚岀殑錛庛
浣庢晥: SELECT…. FROM LOCATION WHERE LOC_ID = 10 OR LOC_ID = 20 OR LOC_ID = 30 楂樻晥 SELECT… FROM LOCATION WHERE LOC_IN IN (10,20,30);
錛?6錛?閬垮厤鍦ㄧ儲寮曞垪涓婁嬌鐢↖S NULL鍜孖S NOT NULL
閬垮厤鍦ㄧ儲寮曚腑浣跨敤浠諱綍鍙互涓虹┖鐨勫垪錛孫RACLE灝嗘棤娉曚嬌鐢ㄨ绱㈠紩錛庡浜庡崟鍒楃儲寮曪紝鍋囧鍒楀寘鍚┖鍊鹼紝绱㈠紩涓皢涓嶅瓨鍦ㄦ璁板綍. 瀵逛簬澶嶅悎绱㈠紩錛屽亣濡傛瘡涓垪閮戒負絀猴紝绱㈠紩涓悓鏍蜂笉瀛樺湪姝よ褰?銆鍋囧鑷沖皯鏈変竴涓垪涓嶄負絀猴紝鍒欒褰曞瓨鍦ㄤ簬绱㈠紩涓紟涓句緥: 鍋囧鍞竴鎬х儲寮曞緩绔嬪湪琛ㄧ殑A鍒楀拰B鍒椾笂, 騫朵笖琛ㄤ腑瀛樺湪涓鏉¤褰曠殑A,B鍊間負(123,null) , ORACLE灝嗕笉鎺ュ彈涓嬩竴鏉″叿鏈夌浉鍚孉,B鍊鹼紙123,null錛夌殑璁板綍(鎻掑叆). 鐒惰屽亣濡傛墍鏈夌殑绱㈠紩鍒楅兘涓虹┖錛孫RACLE灝嗚涓烘暣涓敭鍊間負絀鴻岀┖涓嶇瓑浜庣┖. 鍥犳浣犲彲浠ユ彃鍏?000 鏉″叿鏈夌浉鍚岄敭鍊肩殑璁板綍,褰撶劧瀹冧滑閮芥槸絀? 鍥犱負絀哄間笉瀛樺湪浜庣儲寮曞垪涓?鎵浠HERE瀛愬彞涓绱㈠紩鍒楄繘琛岀┖鍊兼瘮杈冨皢浣縊RACLE鍋滅敤璇ョ儲寮?
浣庢晥: (绱㈠紩澶辨晥) SELECT … FROM DEPARTMENT WHERE DEPT_CODE IS NOT NULL; 楂樻晥: (绱㈠紩鏈夋晥) SELECT … FROM DEPARTMENT WHERE DEPT_CODE >=0;
錛?7錛?鎬繪槸浣跨敤绱㈠紩鐨勭涓涓垪錛?
鍋囧绱㈠紩鏄緩绔嬪湪澶氫釜鍒椾笂, 鍙湁鍦ㄥ畠鐨勭涓涓垪(leading column)琚玾here瀛愬彞寮曠敤鏃?浼樺寲鍣ㄦ墠浼氶夋嫨浣跨敤璇ョ儲寮? 榪欎篃鏄竴鏉＄畝鍗曡岄噸瑕佺殑瑙勫垯錛屽綋浠呭紩鐢ㄧ儲寮曠殑絎簩涓垪鏃?浼樺寲鍣ㄤ嬌鐢ㄤ簡鍏ㄨ〃鎵弿鑰屽拷鐣ヤ簡绱㈠紩
錛?8錛?鐢║NION-ALL 鏇挎崲UNION ( 鍋囧鏈夊彲鑳界殑璇?錛?
褰揝QL璇彞闇瑕乁NION涓や釜鏌ヨ緇撴灉闆嗗悎鏃?榪欎袱涓粨鏋滈泦鍚堜細浠NION-ALL鐨勬柟寮忚鍚堝茍, 鐒跺悗鍦ㄨ緭鍑烘渶緇堢粨鏋滃墠榪涜鎺掑簭. 鍋囧鐢║NION ALL鏇夸唬UNION, 榪欐牱鎺掑簭灝變笉鏄繀瑕佷簡. 鏁堢巼灝變細鍥犳寰楀埌鎻愰珮. 闇瑕佹敞閲嶇殑鏄紝UNION ALL 灝嗛噸澶嶈緭鍑轟袱涓粨鏋滈泦鍚堜腑鐩稿悓璁板綍. 鍥犳鍚勪綅榪樻槸瑕佷粠涓氬姟闇姹傚垎鏋愪嬌鐢║NION ALL鐨勫彲琛屾? UNION 灝嗗緇撴灉闆嗗悎鎺掑簭,榪欎釜鎿嶄綔浼氫嬌鐢ㄥ埌SORT_AREA_SIZE榪欏潡鍐呭瓨. 瀵逛簬榪欏潡鍐呭瓨鐨勪紭鍖栦篃鏄浉褰撻噸瑕佺殑. 涓嬮潰鐨凷QL鍙互鐢ㄦ潵鏌ヨ鎺掑簭鐨勬秷鑰楅噺
浣庢晥錛?
SELECT ACCT_NUM, BALANCE_AMT FROM DEBIT_TRANSACTIONS
WHERE TRAN_DATE = '31-DEC-95' UNION SELECT ACCT_NUM, BALANCE_AMT
FROM DEBIT_TRANSACTIONS WHERE TRAN_DATE = '31-DEC-95' 楂樻晥: SELECT ACCT_NUM, BALANCE_AMT
FROM DEBIT_TRANSACTIONS WHERE TRAN_DATE = '31-DEC-95' UNION ALL SELECT ACCT_NUM, BALANCE_AMT
FROM DEBIT_TRANSACTIONS WHERE TRAN_DATE = '31-DEC-95'
錛?9錛?鐢╓HERE鏇夸唬ORDER BY錛?
ORDER BY 瀛愬彞鍙湪涓ょ涓ユ牸鐨勬潯浠朵笅浣跨敤绱㈠紩.
ORDER BY涓墍鏈夌殑鍒楀繀欏誨寘鍚湪鐩稿悓鐨勭儲寮曚腑騫朵繚鎸佸湪绱㈠紩涓殑鎺掑垪欏哄簭.
ORDER BY涓墍鏈夌殑鍒楀繀欏誨畾涔変負闈炵┖.
WHERE瀛愬彞浣跨敤鐨勭儲寮曞拰ORDER BY瀛愬彞涓墍浣跨敤鐨勭儲寮曚笉鑳藉茍鍒?
渚嬪: 琛―EPT鍖呭惈浠ヤ笅鍒?
DEPT_CODE PK NOT NULL
DEPT_DESC NOT NULL
DEPT_TYPE NULL
浣庢晥: (绱㈠紩涓嶈浣跨敤) SELECT DEPT_CODE FROM DEPT ORDER BY DEPT_TYPE 楂樻晥: (浣跨敤绱㈠紩) SELECT DEPT_CODE FROM DEPT WHERE DEPT_TYPE > 0
錛?0錛?閬垮厤鏀瑰彉绱㈠紩鍒楃殑綾誨瀷.:
褰撴瘮杈冧笉鍚屾暟鎹被鍨嬬殑鏁版嵁鏃? ORACLE鑷姩瀵瑰垪榪涜綆鍗曠殑綾誨瀷杞崲.
鍋囪 EMPNO鏄竴涓暟鍊肩被鍨嬬殑绱㈠紩鍒? SELECT … FROM EMP WHERE EMPNO = ‘123' 瀹為檯涓?緇忚繃ORACLE綾誨瀷杞崲, 璇彞杞寲涓? SELECT … FROM EMP WHERE EMPNO = TO_NUMBER(‘123') 騫歌繍鐨勬槸,綾誨瀷杞崲娌℃湁鍙戠敓鍦ㄧ儲寮曞垪涓?绱㈠紩鐨勭敤閫旀病鏈夎鏀瑰彉. 鐜板湪,鍋囪EMP_TYPE鏄竴涓瓧絎︾被鍨嬬殑绱㈠紩鍒? SELECT … FROM EMP WHERE EMP_TYPE = 123 榪欎釜璇彞琚玂RACLE杞崲涓? SELECT … FROM EMP WHERETO_NUMBER(EMP_TYPE)=123 鍥犱負鍐呴儴鍙戠敓鐨勭被鍨嬭漿鎹? 榪欎釜绱㈠紩灝嗕笉浼氳鐢ㄥ埌! 涓轟簡閬垮厤ORACLE瀵逛綘鐨凷QL榪涜闅愬紡鐨勭被鍨嬭漿鎹? 鏈濂芥妸綾誨瀷杞崲鐢ㄦ樉寮忚〃鐜板嚭鏉? 娉ㄩ噸褰撳瓧絎﹀拰鏁板兼瘮杈冩椂, ORACLE浼氫紭鍏堣漿鎹㈡暟鍊肩被鍨嬪埌瀛楃綾誨瀷
錛?1錛?闇瑕佸綋蹇冪殑WHERE瀛愬彞:
鏌愪簺SELECT 璇彞涓殑WHERE瀛愬彞涓嶄嬌鐢ㄧ儲寮? 榪欓噷鏈変竴浜涗緥瀛? 鍦ㄤ笅闈㈢殑渚嬪瓙閲? (1)‘!=' 灝嗕笉浣跨敤绱㈠紩. 璁頒綇, 绱㈠紩鍙兘鍛婅瘔浣犱粈涔堝瓨鍦ㄤ簬琛ㄤ腑, 鑰屼笉鑳藉憡璇変綘浠涔堜笉瀛樺湪浜庤〃涓? (2) ‘'鏄瓧絎﹁繛鎺ュ嚱鏁? 灝辮薄鍏朵粬鍑芥暟閭ｆ牱, 鍋滅敤浜嗙儲寮? (3) ‘+'鏄暟瀛﹀嚱鏁? 灝辮薄鍏朵粬鏁板鍑芥暟閭ｆ牱, 鍋滅敤浜嗙儲寮? (4)鐩稿悓鐨勭儲寮曞垪涓嶈兘浜掔浉姣旇緝,榪欏皢浼氬惎鐢ㄥ叏琛ㄦ壂鎻?
錛?2錛?a. 鍋囧媯绱㈡暟鎹噺瓚呰繃30%鐨勮〃涓褰曟暟.浣跨敤绱㈠紩灝嗘病鏈夋樉钁楃殑鏁堢巼鎻愰珮.
b. 鍦ㄧ壒瀹氭儏鍐典笅, 浣跨敤绱㈠紩涔熻浼氭瘮鍏ㄨ〃鎵弿鎱? 浣嗚繖鏄悓涓涓暟閲忕駭涓婄殑鍖哄埆. 鑰岄氬父鎯呭喌涓?浣跨敤绱㈠紩姣斿叏琛ㄦ壂鎻忚鍧楀嚑鍊嶄箖鑷沖嚑鍗冨?
錛?3錛?閬垮厤浣跨敤鑰楄垂璧勬簮鐨勬搷浣?
甯︽湁DISTINCT,UNION,MINUS,INTERSECT,ORDER BY鐨凷QL璇彞浼氬惎鍔⊿QL寮曟搸 鎵ц鑰楄垂璧勬簮鐨勬帓搴?SORT)鍔熻兘. DISTINCT闇瑕佷竴嬈℃帓搴忔搷浣? 鑰屽叾浠栫殑鑷沖皯闇瑕佹墽琛屼袱嬈℃帓搴? 閫氬父, 甯︽湁UNION, MINUS , INTERSECT鐨凷QL璇彞閮藉彲浠ョ敤鍏朵粬鏂瑰紡閲嶅啓. 鍋囧浣犵殑鏁版嵁搴撶殑SORT_AREA_SIZE璋冮厤寰楀ソ, 浣跨敤UNION , MINUS, INTERSECT涔熸槸鍙互鑰冭檻鐨? 絀剁珶瀹冧滑鐨勫彲璇繪у緢寮?
錛?4錛?浼樺寲GROUP BY:
鎻愰珮GROUP BY 璇彞鐨勬晥鐜? 鍙互閫氳繃灝嗕笉闇瑕佺殑璁板綍鍦℅ROUP BY 涔嬪墠榪囨護鎺?涓嬮潰涓や釜鏌ヨ榪斿洖鐩稿悓緇撴灉浣嗙浜屼釜鏄庢樉灝卞揩浜嗚澶?
浣庢晥:
SELECT JOB , AVG(SAL) FROM EMP GROUP JOB HAVING JOB = ‘PRESIDENT' OR JOB = ‘MANAGER' 楂樻晥: SELECT JOB , AVG(SAL) FROM EMP WHERE JOB = ‘PRESIDENT' OR JOB = ‘MANAGER' GROUP JOB鏈枃鍑鴻嚜 51CTO.COM鎶鏈崥瀹?/a>
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