| 澶辨晥閾炬帴澶勭悊 |
|
MySQL甯歌絎旇瘯棰橀檮絳旀 PDF 涓嬭澆 涓嬭澆鍦板潃錛?/strong>
閾炬帴錛歨ttps://pan.baidu.com/s/1W_HRBr8EXYAMagaUjEP-4w
鎻愬彇鐮侊細(xì)udms
鐩稿叧鎴浘錛?br />  涓昏鍐呭錛?/strong>
1銆佷竴寮犺〃錛岄噷闈㈡湁 ID 鑷涓婚敭錛屽綋 insert 浜?17 鏉¤褰曚箣鍚庯紝鍒犻櫎浜嗙 15,16,17 鏉¤褰曪紝
鍐嶆妸 Mysql 閲嶅惎錛屽啀 insert 涓€鏉¤褰曪紝榪欐潯璁板綍鐨?ID 鏄?18 榪樻槸 15 錛?/div>
(1)濡傛灉琛ㄧ殑綾誨瀷鏄?MyISAM錛岄偅涔堟槸 18
鍥犱負(fù) MyISAM 琛ㄤ細(xì)鎶婅嚜澧炰富閿殑鏈€澶?ID 璁板綍鍒版暟鎹枃浠墮噷錛岄噸鍚?MySQL 鑷涓婚敭鐨勬渶澶?/div>
ID 涔熶笉浼?xì)涓㈠?/div>
錛?錛夊鏋滆〃鐨勭被鍨嬫槸 InnoDB錛岄偅涔堟槸 15
InnoDB 琛ㄥ彧鏄妸鑷涓婚敭鐨勬渶澶?ID 璁板綍鍒板唴瀛樹腑錛屾墍浠ラ噸鍚暟鎹簱鎴栬€呮槸瀵硅〃榪涜
OPTIMIZE 鎿嶄綔錛岄兘浼?xì)瀵艰嚧鏈€澶?ID 涓㈠け
2銆丮ysql 鐨勬妧鏈壒鐐規(guī)槸浠€涔堬紵
Mysql 鏁版嵁搴撹蔣浠舵槸涓€涓鎴風(fēng)鎴栨湇鍔″櫒緋葷粺錛屽叾涓寘鎷細(xì)鏀寔鍚勭瀹㈡埛绔▼搴忓拰搴撶殑澶?/div>
綰跨▼ SQL 鏈嶅姟鍣ㄣ€佷笉鍚岀殑鍚庣銆佸箍娉涚殑搴旂敤紼嬪簭緙栫▼鎺ュ彛鍜岀鐞嗗伐鍏楓€?/div>
3銆丠eap 琛ㄦ槸浠€涔堬紵
HEAP 琛ㄥ瓨鍦ㄤ簬鍐呭瓨涓紝鐢ㄤ簬涓存椂楂橀€熷瓨鍌ㄣ€?/div>
BLOB 鎴?TEXT 瀛楁鏄笉鍏佽鐨?/div>
鍙兘浣跨敤姣旇緝榪愮畻絎?錛?lt;錛?gt;錛?>錛? <
HEAP 琛ㄤ笉鏀寔 AUTO_INCREMENT
绱㈠紩涓嶅彲涓?NULL
4銆丮ysql 鏈嶅姟鍣ㄩ粯璁ょ鍙ｆ槸浠€涔堬紵
Mysql 鏈嶅姟鍣ㄧ殑榛樿绔彛鏄?3306銆?5銆佷笌 Oracle 鐩告瘮錛孧ysql 鏈変粈涔堜紭鍔匡紵
Mysql 鏄紑婧愯蔣浠訛紝闅忔椂鍙敤錛屾棤闇€浠樿垂銆?/div>
Mysql 鏄究鎼哄紡鐨?/div>
甯︽湁鍛戒護(hù)鎻愮ず絎︾殑 GUI銆?/div>
浣跨敤 Mysql 鏌ヨ嫻忚鍣ㄦ敮鎸佺鐞?/div>
6銆佸浣曞尯鍒?FLOAT 鍜?DOUBLE錛?/div>
浠ヤ笅鏄?FLOAT 鍜?DOUBLE 鐨勫尯鍒細(xì)
嫻偣鏁頒互 8 浣嶇簿搴﹀瓨鍌ㄥ湪 FLOAT 涓紝騫朵笖鏈夊洓涓瓧鑺傘€?/div>
嫻偣鏁板瓨鍌ㄥ湪 DOUBLE 涓紝綺懼害涓?18 浣嶏紝鏈夊叓涓瓧鑺傘€?/div>
7銆佸尯鍒?CHAR_LENGTH 鍜?LENGTH錛?/div>
CHAR_LENGTH 鏄瓧絎︽暟錛岃€?LENGTH 鏄瓧鑺傛暟銆侺atin 瀛楃鐨勮繖涓や釜鏁版嵁鏄浉鍚岀殑錛屼絾鏄
浜?Unicode 鍜屽叾浠栫紪鐮侊紝瀹冧滑鏄笉鍚岀殑銆?/div>
8銆佽綆€媧佹弿榪?Mysql 涓?InnoDB 鏀寔鐨勫洓縐嶄簨鍔￠殧紱葷駭鍒悕縐幫紝浠ュ強(qiáng)閫愮駭涔嬮棿鐨勫尯鍒紵
SQL 鏍囧噯瀹氫箟鐨勫洓涓殧紱葷駭鍒負(fù)錛?/div>
read uncommited 錛氳鍒版湭鎻愪氦鏁版嵁
read committed錛氳剰璇伙紝涓嶅彲閲嶅璇?/div>
repeatable read錛氬彲閲嶈
serializable 錛氫覆琛屼簨鐗?/div>
9銆佸湪 Mysql 涓?ENUM 鐨勭敤娉曟槸浠€涔堬紵
ENUM 鏄竴涓瓧絎︿覆瀵硅薄錛岀敤浜庢寚瀹氫竴緇勯瀹氫箟鐨勫€鹼紝騫跺彲鍦ㄥ垱寤鴻〃鏃朵嬌鐢ㄣ€?/div>
Create table size(name ENUM('Smail,'Medium','Large');
10銆佸浣曞畾涔?REGEXP錛?/div>
REGEXP 鏄ā寮忓尮閰嶏紝鍏朵腑鍖歸厤妯″紡鍦ㄦ悳绱㈠€肩殑浠諱綍浣嶇疆銆?/div>
11銆丆HAR 鍜?VARCHAR 鐨勫尯鍒紵
浠ヤ笅鏄?CHAR 鍜?VARCHAR 鐨勫尯鍒細(xì)
CHAR 鍜?VARCHAR 綾誨瀷鍦ㄥ瓨鍌ㄥ拰媯€绱㈡柟闈㈡湁鎵€涓嶅悓
CHAR 鍒楅暱搴﹀浐瀹氫負(fù)鍒涘緩琛ㄦ椂澹版槑鐨勯暱搴︼紝闀垮害鍊艱寖鍥存槸 1 鍒?255
褰?CHAR 鍊艱瀛樺偍鏃訛紝瀹冧滑琚敤絀烘牸濉厖鍒扮壒瀹氶暱搴︼紝媯€绱?CHAR 鍊兼椂闇€鍒犻櫎灝鵑殢絀烘牸銆?/div>
12銆佸垪鐨勫瓧絎︿覆綾誨瀷鍙互鏄粈涔堬紵
瀛楃涓茬被鍨嬫槸錛?/div>
SET
BLOB
ENUM
CHAR
TEXT
VARCHAR
13銆佸浣曡幏鍙栧綋鍓嶇殑 Mysql 鐗堟湰錛?/div>
SELECT VERSION();鐢ㄤ簬鑾峰彇褰撳墠 Mysql 鐨勭増鏈€?/div>
14銆丮ysql 涓嬌鐢ㄤ粈涔堝瓨鍌ㄥ紩鎿庯紵
瀛樺偍寮曟搸縐頒負(fù)琛ㄧ被鍨嬶紝鏁版嵁浣跨敤鍚勭鎶€鏈瓨鍌ㄥ湪鏂囦歡涓€?/div>
鎶€鏈秹鍙?qiáng)锛?xì)
Storage mechanism
Locking levels
Indexing
Capabilities and functions.
15銆丮ysql 椹卞姩紼嬪簭鏄粈涔堬紵
浠ヤ笅鏄?Mysql 涓彲鐢ㄧ殑椹卞姩紼嬪簭錛?/div>
PHP 椹卞姩紼嬪簭
JDBC 椹卞姩紼嬪簭
ODBC 椹卞姩紼嬪簭
CWRAPPER
PYTHON 椹卞姩紼嬪簭
PERL 椹卞姩紼嬪簭
RUBY 椹卞姩紼嬪簭
CAP11PHP 椹卞姩紼嬪簭
Ado.net5.mxj
16銆乀IMESTAMP 鍦?UPDATE CURRENT_TIMESTAMP 鏁版嵁綾誨瀷涓婂仛浠€涔堬紵
鍒涘緩琛ㄦ椂 TIMESTAMP 鍒楃敤 Zero 鏇存柊銆傚彧瑕佽〃涓殑鍏朵粬瀛楁鍙戠敓鏇存敼錛孶PDATE
CURRENT_TIMESTAMP 淇グ絎﹀氨灝嗘椂闂存埑瀛楁鏇存柊涓哄綋鍓嶆椂闂淬€?/div>
17銆佷富閿拰鍊欓€夐敭鏈変粈涔堝尯鍒紵
琛ㄦ牸鐨勬瘡涓€琛岄兘鐢變富閿敮涓€鏍囪瘑,涓€涓〃鍙湁涓€涓富閿€?/div>
涓婚敭涔熸槸鍊欓€夐敭銆傛寜鐓ф儻渚嬶紝鍊欓€夐敭鍙互琚寚瀹氫負(fù)涓婚敭錛屽茍涓斿彲浠ョ敤浜庝換浣曞閿紩鐢ㄣ€?/div>
18銆佸浣曚嬌鐢?Unix shell 鐧誨綍 Mysql錛?/div>
鎴戜滑鍙互閫氳繃浠ヤ笅鍛戒護(hù)鐧誨綍錛?/div>
[mysql dir]/bin/mysql -h hostname -u
19銆?myisamchk 鏄敤鏉ュ仛浠€涔堢殑錛?/div>
瀹冪敤鏉ュ帇緙?MyISAM 琛紝榪欏噺灝戜簡紓佺洏鎴栧唴瀛樹嬌鐢ㄣ€?/div>
20銆丮YSQL 鏁版嵁搴撴湇鍔″櫒鎬ц兘鍒嗘瀽鐨勬柟娉曞懡浠ゆ湁鍝簺?
21銆佸浣曟帶鍒?HEAP 琛ㄧ殑鏈€澶у昂瀵革紵
Heal 琛ㄧ殑澶у皬鍙€氳繃縐頒負(fù) max_heap_table_size 鐨?Mysql 閰嶇疆鍙橀噺鏉ユ帶鍒躲€?/div>
22銆丮yISAM Static 鍜?MyISAM Dynamic 鏈変粈涔堝尯鍒紵
鍦?MyISAM Static 涓婄殑鎵€鏈夊瓧孌墊湁鍥哄畾瀹藉害銆傚姩鎬?MyISAM 琛ㄥ皢鍏鋒湁鍍?TEXT錛孊LOB 絳夊瓧
孌碉紝浠ラ€傚簲涓嶅悓闀垮害鐨勬暟鎹被鍨嬨€傜偣鍑昏繖閲屾湁涓€濂楁渶鍏ㄩ樋閲岄潰璇曢鎬葷粨銆?/div>
MyISAM Static 鍦ㄥ彈鎹熸儏鍐典笅鏇村鏄撴仮澶嶃€?/div>
23銆乫ederated 琛ㄦ槸浠€涔堬紵
federated 琛紝鍏佽璁塊棶浣嶄簬鍏朵粬鏈嶅姟鍣ㄦ暟鎹簱涓婄殑琛ㄣ€?/div>
24銆佸鏋滀竴涓〃鏈変竴鍒楀畾涔変負(fù) TIMESTAMP錛屽皢鍙戠敓浠€涔堬紵
姣忓綋琛岃鏇存敼鏃訛紝鏃墮棿鎴沖瓧孌靛皢鑾峰彇褰撳墠鏃墮棿鎴熾€?/div>
25銆佸垪璁劇疆涓?AUTO INCREMENT 鏃訛紝濡傛灉鍦ㄨ〃涓揪鍒版渶澶у€鹼紝浼?xì)鍙戠敓浠€涔堟儏鍐碉紵
瀹冧細(xì)鍋滄閫掑錛屼換浣曡繘涓€姝ョ殑鎻掑叆閮藉皢浜х敓閿欒錛屽洜涓哄瘑閽ュ凡琚嬌鐢ㄣ€?/div>
26銆佹€庢牱鎵嶈兘鎵懼嚭鏈€鍚庝竴嬈℃彃鍏ユ椂鍒嗛厤浜嗗摢涓嚜鍔ㄥ閲忥紵
LAST_INSERT_ID 灝嗚繑鍥炵敱 Auto_increment 鍒嗛厤鐨勬渶鍚庝竴涓€鹼紝騫朵笖涓嶉渶瑕佹寚瀹氳〃鍚嶇О銆?/div>
27銆佷綘鎬庝箞鐪嬪埌涓鴻〃鏍煎畾涔夌殑鎵€鏈夌儲寮曪紵
绱㈠紩鏄€氳繃浠ヤ笅鏂瑰紡涓鴻〃鏍煎畾涔夌殑錛?/div>
SHOW INDEX FROM
28.銆丩IKE 澹版槑涓殑錛呭拰_鏄粈涔堟剰鎬濓紵
錛呭搴斾簬 0 涓垨鏇村瀛楃錛宊鍙槸 LIKE 璇彞涓殑涓€涓瓧絎︺€?/div>
29銆佸浣曞湪 Unix 鍜?Mysql 鏃墮棿鎴充箣闂磋繘琛岃漿鎹紵
UNIX_TIMESTAMP 鏄粠 Mysql 鏃墮棿鎴寵漿鎹負(fù) Unix 鏃墮棿鎴崇殑鍛戒護(hù)
FROM_UNIXTIME 鏄粠 Unix 鏃墮棿鎴寵漿鎹負(fù) Mysql 鏃墮棿鎴崇殑鍛戒護(hù)
30銆佸垪瀵規(guī)瘮榪愮畻絎︽槸浠€涔堬紵
鍦?SELECT 璇彞鐨勫垪姣旇緝涓嬌鐢?錛?lt;>錛?lt;=錛?lt;錛?gt; =錛?gt;錛?lt;<錛?gt;>錛?lt;=>錛孉ND錛孫R 鎴?LIKE 榪?/div>
綆楃銆?/div>
31銆佹垜浠浣曞緱鍒板彈鏌ヨ褰卞搷鐨勮鏁幫紵
琛屾暟鍙互閫氳繃浠ヤ笅浠ｇ爜鑾峰緱錛?/div>
SELECT COUNT(user_id)FROM users;
32銆丮ysql 鏌ヨ鏄惁鍖哄垎澶у皬鍐欙紵
涓嶅尯鍒?/div>
SELECT VERSION(), CURRENT_DATE;
SeLect version(), current_date;
seleCt vErSiOn(), current_DATE;
鎵€鏈夎繖浜涗緥瀛愰兘鏄竴鏍風(fēng)殑錛孧ysql 涓嶅尯鍒嗗ぇ灝忓啓銆?/div>
33.銆丩IKE 鍜?REGEXP 鎿嶄綔鏈変粈涔堝尯鍒紵
LIKE 鍜?REGEXP 榪愮畻絎︾敤浜庤〃紺篰鍜岋紖銆?/div>
SELECT * FROM employee WHERE emp_name REGEXP "^b";
SELECT * FROM employee WHERE emp_name LIKE "%b";
34.銆丅LOB 鍜?TEXT 鏈変粈涔堝尯鍒紵
BLOB 鏄竴涓簩榪涘埗瀵硅薄錛屽彲浠ュ綰沖彲鍙樻暟閲忕殑鏁版嵁銆傛湁鍥涚綾誨瀷鐨?BLOB -
TINYBLOB
BLOB
MEDIUMBLOB 鍜?/div>
LONGBLOB
瀹冧滑鍙兘鍦ㄦ墍鑳藉綰充環(huán)鍊肩殑鏈€澶ч暱搴︿笂鏈夋墍涓嶅悓銆?/div>
TEXT 鏄竴涓笉鍖哄垎澶у皬鍐欑殑 BLOB銆傚洓縐?TEXT 綾誨瀷
TINYTEXT
TEXT
MEDIUMTEXT 鍜?/div>
LONGTEXT
瀹冧滑瀵瑰簲浜庡洓縐?BLOB 綾誨瀷錛屽茍鍏鋒湁鐩稿悓鐨勬渶澶ч暱搴﹀拰瀛樺偍瑕佹眰銆?/div>
BLOB 鍜?TEXT 綾誨瀷涔嬮棿鐨勫敮涓€鍖哄埆鍦ㄤ簬瀵?BLOB 鍊艱繘琛屾帓搴忓拰姣旇緝鏃跺尯鍒嗗ぇ灝忓啓錛屽 TEXT
鍊間笉鍖哄垎澶у皬鍐欍€?/div>
35銆乵ysql_fetch_array 鍜?mysql_fetch_object 鐨勫尯鍒槸浠€涔堬紵
浠ヤ笅鏄?mysql_fetch_array 鍜?mysql_fetch_object 鐨勫尯鍒細(xì)
mysql_fetch_array錛堬級 - 灝嗙粨鏋滆浣滀負(fù)鍏寵仈鏁扮粍鎴栨潵鑷暟鎹簱鐨勫父瑙勬暟緇勮繑鍥炪€?/div>
mysql_fetch_object - 浠庢暟鎹簱榪斿洖緇撴灉琛屼綔涓哄璞°€?/div>
36銆佹垜浠浣曞湪 mysql 涓繍琛屾壒澶勭悊妯″紡錛?/div>
浠ヤ笅鍛戒護(hù)鐢ㄤ簬鍦ㄦ壒澶勭悊妯″紡涓嬭繍琛岋細(xì)
mysql;
mysql mysql.out
37銆丮yISAM 琛ㄦ牸灝嗗湪鍝噷瀛樺偍錛屽茍涓旇繕鎻愪緵鍏跺瓨鍌ㄦ牸寮忥紵
姣忎釜 MyISAM 琛ㄦ牸浠ヤ笁縐嶆牸寮忓瓨鍌ㄥ湪紓佺洏涓婏細(xì)
·“.frm”鏂囦歡瀛樺偍琛ㄥ畾涔?/div>
·鏁版嵁鏂囦歡鍏鋒湁“.MYD”錛圡YData錛夋墿灞曞悕
绱㈠紩鏂囦歡鍏鋒湁“.MYI”錛圡YIndex錛夋墿灞曞悕
38.銆丮ysql 涓湁鍝簺涓嶅悓鐨勮〃鏍鹼紵
鍏辨湁 5 縐嶇被鍨嬬殑琛ㄦ牸錛?/div>
MyISAM
Heap
Merge
INNODB
ISAM
MyISAM 鏄?Mysql 鐨勯粯璁ゅ瓨鍌ㄥ紩鎿庛€?/div>
39銆両SAM 鏄粈涔堬紵
ISAM 綆€縐頒負(fù)绱㈠紩欏哄簭璁塊棶鏂規(guī)硶銆傚畠鏄敱 IBM 寮€鍙戠殑錛岀敤浜庡湪紓佸甫絳夎緟鍔╁瓨鍌ㄧ郴緇熶笂瀛樺偍鍜?/div>
媯€绱㈡暟鎹€?/div>
40銆両nnoDB 鏄粈涔堬紵
lnnoDB 鏄竴涓敱 Oracle 鍏徃寮€鍙戠殑 Innobase Oy 浜嬪姟瀹夊叏瀛樺偍寮曟搸銆?/div>
41銆丮ysql 濡備綍浼樺寲 DISTINCT錛?/div>
DISTINCT 鍦ㄦ墍鏈夊垪涓婅漿鎹負(fù) GROUP BY錛屽茍涓?ORDER BY 瀛愬彞緇撳悎浣跨敤銆?/div>
1
SELECT DISTINCT t1.a FROM t1,t2 where t1.a=t2.a;
42銆佸浣曡緭鍏ュ瓧絎︿負(fù)鍗佸叚榪涘埗鏁板瓧錛?/div>
濡傛灉鎯寵緭鍏ュ瓧絎︿負(fù)鍗佸叚榪涘埗鏁板瓧錛屽彲浠ヨ緭鍏ュ甫鏈夊崟寮曞彿鐨勫崄鍏繘鍒舵暟瀛楀拰鍓嶇紑錛圶錛夛紝鎴栬€?/div>
鍙敤錛圤x錛夊墠緙€杈撳叆鍗佸叚榪涘埗鏁板瓧銆?/div>
濡傛灉琛ㄨ揪寮忎笂涓嬫枃鏄瓧絎︿覆錛屽垯鍗佸叚榪涘埗鏁板瓧涓插皢鑷姩杞崲涓哄瓧絎︿覆銆?/div>
43銆佸浣曟樉紺哄墠 50 琛岋紵
鍦?Mysql 涓紝浣跨敤浠ヤ笅浠ｇ爜鏌ヨ鏄劇ず鍓?50 琛岋細(xì)
SELECT*FROM
LIMIT 0,50;
44銆佸彲浠ヤ嬌鐢ㄥ灝戝垪鍒涘緩绱㈠紩錛?/div>
浠諱綍鏍囧噯琛ㄦ渶澶氬彲浠ュ垱寤?16 涓儲寮曞垪銆?/div>
45銆丯OW錛堬級鍜?CURRENT_DATE錛堬級鏈変粈涔堝尯鍒紵
NOW錛堬級鍛戒護(hù)鐢ㄤ簬鏄劇ず褰撳墠騫翠喚錛屾湀浠斤紝鏃ユ湡錛屽皬鏃訛紝鍒嗛挓鍜岀銆?/div>
CURRENT_DATE錛堬級浠呮樉紺哄綋鍓嶅勾浠斤紝鏈堜喚鍜屾棩鏈熴€?/div>
46銆佷粈涔堟牱鐨勫璞″彲浠ヤ嬌鐢?CREATE 璇彞鍒涘緩錛?/div>
浠ヤ笅瀵硅薄鏄嬌鐢?CREATE 璇彞鍒涘緩鐨勶細(xì)
DATABASE
EVENT
FUNCTION
INDEX
PROCEDURE
TABLE
TRIGGER
USER
VIEW
47銆丮ysql 琛ㄤ腑鍏佽鏈夊灝戜釜 TRIGGERS錛?鍦?Mysql 琛ㄤ腑鍏佽鏈夊叚涓Е鍙戝櫒錛屽涓嬶細(xì)
BEFORE INSERT
AFTER INSERT
BEFORE UPDATE
AFTER UPDATE
BEFORE DELETE
AFTER DELETE
48銆佷粈涔堟槸闈炴爣鍑嗗瓧絎︿覆綾誨瀷錛?/div>
浠ヤ笅鏄潪鏍囧噯瀛楃涓茬被鍨嬶細(xì)
TINYTEXT
TEXT
MEDIUMTEXT
LONGTEXT
49銆佷粈涔堟槸閫氱敤 SQL 鍑芥暟錛?/div>
CONCAT(A, B) - 榪炴帴涓や釜瀛楃涓插€間互鍒涘緩鍗曚釜瀛楃涓茶緭鍑恒€傞€氬父鐢ㄤ簬灝嗕袱涓垨澶氫釜瀛楁鍚?/div>
騫朵負(fù)涓€涓瓧孌點(diǎn)€?/div>
FORMAT(X, D)- 鏍煎紡鍖栨暟瀛?X 鍒?D 鏈夋晥鏁板瓧銆?/div>
CURRDATE(), CURRTIME()- 榪斿洖褰撳墠鏃ユ湡鎴栨椂闂淬€?/div>
NOW錛堬級 - 灝嗗綋鍓嶆棩鏈熷拰鏃墮棿浣滀負(fù)涓€涓€艱繑鍥炪€?/div>
MONTH錛堬級錛孌AY錛堬級錛孻EAR錛堬級錛學(xué)EEK錛堬級錛學(xué)EEKDAY錛堬級 - 浠庢棩鏈熷€間腑鎻愬彇緇欏畾鏁版嵁銆?/div>
HOUR錛堬級錛孧INUTE錛堬級錛孲ECOND錛堬級 - 浠庢椂闂村€間腑鎻愬彇緇欏畾鏁版嵁銆?/div>
DATEDIFF錛圓錛孊錛?- 紜畾涓や釜鏃ユ湡涔嬮棿鐨勫樊寮傦紝閫氬父鐢ㄤ簬璁＄畻騫撮緞
SUBTIMES錛圓錛孊錛?- 紜畾涓ゆ涔嬮棿鐨勫樊寮傘€?/div>
FROMDAYS錛圛NT錛?- 灝嗘暣鏁板ぉ鏁拌漿鎹負(fù)鏃ユ湡鍊箋€?/div>
50銆佽В閲婅闂帶鍒跺垪琛?/div>
ACL錛堣闂帶鍒跺垪琛級鏄笌瀵硅薄鍏寵仈鐨勬潈闄愬垪琛ㄣ€傝繖涓垪琛ㄦ槸 Mysql 鏈嶅姟鍣ㄥ畨鍏ㄦā鍨嬬殑鍩?/div>
紜€錛屽畠鏈夊姪浜庢帓闄ょ敤鎴鋒棤娉曡繛鎺ョ殑闂銆?/div>
Mysql 灝?ACL錛堜篃縐頒負(fù)鎺堟潈琛級緙撳瓨鍦ㄥ唴瀛樹腑銆傚綋鐢ㄦ埛灝濊瘯璁よ瘉鎴栬繍琛屽懡浠ゆ椂錛孧ysql 浼?xì)鎸?/div>
鐓ч瀹氱殑欏哄簭媯€鏌?ACL 鐨勮璇佷俊鎭拰鏉冮檺銆?/div>
51銆丮YSQL 鏀寔浜嬪姟鍚楋紵
鍦ㄧ己鐪佹ā寮忎笅錛孧YSQL 鏄?autocommit 妯″紡鐨勶紝鎵€鏈夌殑鏁版嵁搴撴洿鏂版搷浣滈兘浼?xì)鍗虫椂鎻愪氦锛屾墍
浠ュ湪緙虹渷鎯呭喌涓嬶紝mysql 鏄笉鏀寔浜嬪姟鐨勩€?/div>
浣嗘槸濡傛灉浣犵殑 MYSQL 琛ㄧ被鍨嬫槸浣跨敤 InnoDB Tables 鎴?BDB tables 鐨勮瘽錛屼綘鐨?MYSQL 灝卞彲浠?/div>
浣跨敤浜嬪姟澶勭悊,浣跨敤 SET AUTOCOMMIT=0 灝卞彲浠ヤ嬌 MYSQL 鍏佽鍦ㄩ潪 autocommit 妯″紡錛屽湪闈?/div>
autocommit 妯″紡涓嬶紝浣犲繀欏諱嬌鐢?COMMIT 鏉ユ彁浜や綘鐨勬洿鏀癸紝鎴栬€呯敤 ROLLBACK 鏉ュ洖婊氫綘鐨?/div>
鏇存敼銆?/div>
紺轟緥濡備笅錛?/div>
涓€
START TRANSACTION;
SELECT @A:=SUM(salary) FROM table1 WHERE type=1;
UPDATE table2 SET summmary=@A WHERE type=1;
COMMIT;
52銆乵ysql 閲岃褰曡揣甯佺敤浠€涔堝瓧孌電被鍨嬪ソ
NUMERIC 鍜?DECIMAL 綾誨瀷琚?Mysql 瀹炵幇涓哄悓鏍風(fēng)殑綾誨瀷錛岃繖鍦?SQL92 鏍囧噯鍏佽銆備粬浠鐢ㄤ簬
淇濆瓨鍊鹼紝璇ュ€肩殑鍑嗙‘綺懼害鏄瀬鍏墮噸瑕佺殑鍊鹼紝渚嬪涓庨噾閽辨湁鍏崇殑鏁版嵁銆傚綋澹版槑涓€涓被鏄繖浜?/div>
綾誨瀷涔嬩竴鏃訛紝綺懼害鍜岃妯＄殑鑳借(騫朵笖閫氬父鏄?鎸囧畾錛涚偣鍑昏繖閲屾湁涓€濂楁渶鍏ㄩ樋閲岄潰璇曢鎬?/div>
緇撱€?/div>
渚嬪錛?/div>
salary DECIMAL(9,2)
鍦ㄨ繖涓緥瀛愪腑錛?(precision)浠ｈ〃灝嗚鐢ㄤ簬瀛樺偍鍊肩殑鎬葷殑灝忔暟浣嶆暟錛岃€?2(scale)浠ｈ〃灝嗚鐢ㄤ簬
瀛樺偍灝忔暟鐐瑰悗鐨勪綅鏁般€?/div>
鍥犳錛屽湪榪欑鎯呭喌涓嬶紝鑳借瀛樺偍鍦?salary 鍒椾腑鐨勫€肩殑鑼冨洿鏄粠-9999999.99 鍒?9999999.99銆?鍦?ANSI/ISO SQL92 涓紝鍙ユ硶 DECIMAL(p)絳変環(huán)浜?DECIMAL(p,0)銆?/div>
鍚屾牱錛屽彞娉?DECIMAL 絳変環(huán)浜?DECIMAL(p,0)錛岃繖閲屽疄鐜拌鍏佽鍐沖畾鍊?p銆侻ysql 褰撳墠涓嶆敮鎸?/div>
DECIMAL/NUMERIC 鏁版嵁綾誨瀷鐨勮繖浜涘彉縐嶅艦寮忕殑浠諱竴縐嶃€?/div>
榪欎竴鑸鏉ヤ笉鏄竴涓弗閲嶇殑闂錛屽洜涓鴻繖浜涚被鍨嬬殑涓昏鐩婂寰楄嚜浜庢槑鏄懼湴鎺у埗綺懼害鍜岃妯?/div>
鐨勮兘鍔涖€?/div>
DECIMAL 鍜?NUMERIC 鍊間綔涓哄瓧絎︿覆瀛樺偍錛岃€屼笉鏄綔涓轟簩榪涘埗嫻偣鏁幫紝浠ヤ究淇濆瓨閭ｄ簺鍊肩殑灝?/div>
鏁扮簿搴︺€?/div>
涓€涓瓧絎︾敤浜庡€肩殑姣忎竴浣嶃€佸皬鏁扮偣(濡傛灉 scale>0)鍜?ldquo;-”絎﹀彿(瀵逛簬璐熷€?銆傚鏋?scale 鏄?0錛?/div>
DECIMAL 鍜?NUMERIC 鍊間笉鍖呭惈灝忔暟鐐規(guī)垨灝忔暟閮ㄥ垎銆?/div>
DECIMAL 鍜?NUMERIC 鍊煎緱鏈€澶х殑鑼冨洿涓?DOUBLE 涓€鏍鳳紝浣嗘槸瀵逛簬涓€涓粰瀹氱殑 DECIMAL 鎴?/div>
NUMERIC 鍒楋紝瀹為檯鐨勮寖鍥村彲鐢卞埗鐢辯粰瀹氬垪鐨?precision 鎴?scale 闄愬埗銆?/div>
褰撹繖鏍風(fēng)殑鍒楄祴緇欎簡灝忔暟鐐瑰悗闈㈢殑浣嶈秴榪囨寚瀹?scale 鎵€鍏佽鐨勪綅鐨勫€鹼紝璇ュ€兼牴鎹?scale 鍥涜垗浜?/div>
鍏ャ€?/div>
褰撲竴涓?DECIMAL 鎴?NUMERIC 鍒楄璧嬬粰浜嗗叾澶у皬瓚呰繃鎸囧畾(鎴栫己鐪佺殑錛塸recision 鍜?scale 闅愬惈
鐨勮寖鍥寸殑鍊鹼紝Mysql 瀛樺偍琛ㄧず閭ｄ釜鑼冨洿鐨勭浉搴旂殑绔偣鍊箋€?/div>
鎴戝笇鏈涙湰鏂囧彲浠ュ府鍔╀綘鎻愬崌鎶€鏈按騫熾€傞偅浜涳紝鎰熻瀛︾殑濂介毦錛岀敋鑷充細(xì)浠や綘娌撫鐨勪漢錛屽埆鎷?/div>
蹇冿紝鎴戣涓猴紝濡傛灉浣犳効鎰忚瘯涓€璇曟湰鏂囦粙緇嶇殑鍑犵偣錛屼細(xì)鍚戝墠榪堣繘錛屽厠鏈嶈繖縐嶆劅瑙夈€傝繖浜涜鐐?/div>
涔熻瀵逛綘涓嶉€傜敤錛屼絾浣犱細(xì)鏄庣‘涓€涓噸瑕佺殑閬撶悊錛氭帴鍙楄嚜宸辮寰楀彈鍥拌繖涓簨瀹炴槸鎽嗚劚榪欎釜鍥?/div>
澧冪殑絎竴姝ャ€?/div>
53銆丮YSQL 鏁版嵁琛ㄥ湪浠€涔堟儏鍐典笅瀹規(guī)槗鎹熷潖錛?/div>
鏈嶅姟鍣ㄧ獊鐒舵柇鐢?shù)瀵艰嚧鏁版嵁鏂囦欢鎹熷潖銆?/div>
寮哄埗鍏蟲満錛屾病鏈夊厛鍏抽棴 mysql 鏈嶅姟絳夈€?/div>
54銆乵ysql 鏈夊叧鏉冮檺鐨勮〃閮芥湁鍝嚑涓紵
Mysql 鏈嶅姟鍣ㄩ€氳繃鏉冮檺琛ㄦ潵鎺у埗鐢ㄦ埛瀵規(guī)暟鎹簱鐨勮闂紝鏉冮檺琛ㄥ瓨鏀懼湪 mysql 鏁版嵁搴撻噷錛岀敱
mysql_install_db 鑴氭湰鍒濆鍖栥€傝繖浜涙潈闄愯〃鍒嗗埆 user錛宒b錛宼able_priv錛宑olumns_priv 鍜?/div>
host銆?/div>
55銆丮ysql 涓湁鍝嚑縐嶉攣錛?/div>
MyISAM 鏀寔琛ㄩ攣錛孖nnoDB 鏀寔琛ㄩ攣鍜岃閿侊紝榛樿涓鴻閿?/div>
琛ㄧ駭閿侊細(xì)寮€閿€灝忥紝鍔犻攣蹇紝涓嶄細(xì)鍑虹幇姝婚攣銆傞攣瀹氱矑搴﹀ぇ錛屽彂鐢熼攣鍐茬獊鐨勬鐜囨渶楂橈紝騫跺彂閲?/div>
鏈€浣?/div>
琛岀駭閿侊細(xì)寮€閿€澶э紝鍔犻攣鎱紝浼?xì)鍑虹幇姝婚攣銆傞攣鍔涘害灝忥紝鍙戠敓閿佸啿紿佺殑姒傜巼灝忥紝騫跺彂搴︽渶楂?br />
|
| Java1234瀹樻柟緹?5錛?/td> | 
|
| Java1234瀹樻柟緹?5錛?/td> | 838462530 |
鑻忓叕緗戝畨澶?32061202001004鍙?/p>
