MySQL瀛楁绫诲瀷 绾︽潫

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鐩綍

mysql瀛樺偍寮曟搸

浠€涔堟槸瀛樺偍寮曟搸锛?/p>

鏁版嵁搴撳瓨鍌ㄥ紩鎿庢槸鏁版嵁搴撳簳灞傝蒋浠剁粍浠讹紝鏁版嵁搴撶鐞嗙郴缁熶娇鐢ㄦ暟鎹紩鎿庤繘琛屽垱寤恒€佹煡璇€佹洿鏂板拰鍒犻櫎鏁版嵁鎿嶄綔銆?/strong>鐢ㄤ簬鏍规嵁涓嶅悓鐨勬満鍒跺鐞嗕笉鍚岀殑鏁版嵁

鎻愮ず锛?code>InnoDB 浜嬪姟鍨嬫暟鎹簱鐨勯閫夊紩鎿庯紝鏀寔浜嬪姟瀹夊叏琛紙ACID锛夛紝琛岄攣瀹?鍜?澶栭敭銆傦紙 浜嬪姟涓昏鐢ㄤ簬澶勭悊鎿嶄綔閲忓ぇ锛屽鏉傚害楂樼殑鏁版嵁锛?/p>

MySQL 5.5.5 涔嬪悗锛?code>InnoDB 浣滀负榛樿瀛樺偍寮曟搸銆?/p>

鏌ョ湅MySQL涓墍鏈夊紩鎿?/p> 

show engines

create table t1(id int)engines=innodb;  #鍒涘缓寮曟搸涓篿nnodb鐨勮〃

myisam:5.5浠ュ墠鑰佺殑鐗堟湰浣跨敤鐨勫瓨鍌ㄥ紩鎿庯紝鎷ユ湁杈冮珮鐨勬彃鍏ワ紝鏌ヨ閫熷害锛屼絾涓嶆敮鎸佷簨鐗?/p>

blackhole:绫讳技浜庨槦鍒椾腑鐨勬暟鎹紝瀛樿繘鍘绘秷澶?/p>

memory:閫氱數鏁版嵁瀛樺湪锛屾柇鐢典涪澶?/p>

鍒涘缓琛ㄥ畬鏁寸殑璇硶

绾︽潫鏉′欢锛氬彲鏈夊彲鏃?/p>

瀹藉害锛氶檺鍒舵煇浜涙暟鎹被鍨嬬殑瀛樺偍澶у皬

闈炵┖绾︽潫

鍦ㄥ垱寤鸿〃鏃跺彲浠ョ敤NOT NULL鍏抽敭瀛楄缃潪绌虹害鏉?/p> 

<瀛楁鍚?gt;<鏁版嵁绫诲瀷> NOT NULL

瀹炰緥锛?/p> 

mysql> create table t6(
    id int not null
);
Query OK, 0 rows affected (0.25 sec)

mysql> desc t6;
+-------+---------+------+-----+---------+-------+
| Field | Type    | Null | Key | Default | Extra |
+-------+---------+------+-----+---------+-------+
| id    | int(11) | NO   |     | NULL    |       |
+-------+---------+------+-----+---------+-------+

瀛楁绫诲瀷

鏁村舰绫诲瀷INT TINYINT

SMALLINT MEDIUMINT BIGINT

鏁村舰绫诲瀷鍙堢О鏁板€煎瀷鏁版嵁锛屼富瑕佺敤鏉ュ瓨鍌ㄦ暟瀛椼€?/p>

绫诲瀷鍚嶇О 璇存槑 瀛樺偍闇€姹?/th>
TINYINT 寰堝皬鐨勬暣鏁?/td> 1涓瓧鑺?/td>
SMALLINT 灏忕殑鏁存暟 2涓畤鑺?/td>
MEDIUMINT 涓瓑澶у皬鐨勬暣鏁?/td> 3涓瓧鑺?/td>
INT (INTEGHR) 鏅€氬ぇ灏忕殑鏁存暟 4涓瓧鑺?/td>
BIGINT 澶ф暣鏁?/td> 8涓瓧鑺?/td>

浠庝笂琛ㄤ腑鍙互鐪嬪埌锛屼笉鍚岀被鍨嬬殑鏁存暟瀛樺偍鎵€闇€鐨勫瓧鑺傛暟涓嶇浉鍚岋紝鍗犵敤瀛楄妭鏁版渶灏忕殑鏄?TINYINT 绫诲瀷锛屽崰鐢ㄥ瓧鑺傛渶澶х殑鏄?BIGINT 绫诲瀷锛屽崰鐢ㄧ殑瀛楄妭瓒婂鐨勭被鍨嬫墍鑳借〃绀虹殑鏁板€艰寖鍥磋秺澶с€?/p>

绫诲瀷鍚嶇О 璇存槑 瀛樺偍闇€姹?/th>
TINYINT -128?127 0 ?255
SMALLINT -32768?32767 0?65535
MEDIUMINT -8388608?8388607 0?16777215
INT (INTEGER) -2147483648?2147483647 0?4294967295
BIGINT -9223372036854775808?9223372036854775807 0?18446744073709551615

瀹炰緥锛歵inyint 鑼冨洿 -128?127

create table t7(
    id tinyint
);

瀹炰緥锛歩nt 鑼冨洿 -2147483648?2147483647

create table t8(
    id int
);

鑻ユ彃鍏ヨ秴杩囪瀹氬搴︼紝鍒欐甯告樉绀?/p>

鑻ユ彃鍏ヤ笉瓒筹紝鍒欎互绌烘牸涓嶅叏

娴偣绫诲瀷float

DOUBLE 鍙岀簿搴︽诞鐐规暟

DECIMAL 鍘嬬缉鐨勨€滀弗鏍尖€濆畾鐐规暟

涓夌娴偣鍨嬬殑鍖哄埆鍦ㄤ簬 绮剧‘鍒颁笉涓€鏍?/p>

搴旂敤鍦烘櫙锛氬伐璧勶紝韬珮锛屼綋閲嶃€傘€傘€?/p>

瀹炰緥锛?/p> 

create table t9(sal float(255,30))  #鑼冨洿255鏄渶澶ч暱搴︼紙鍖呮嫭.灏忔暟锛夛紝30浠ｈ〃鐨勬槸灏忔暟鐨勪綅鏁?/code>

瀛楃绫诲瀷char varchar

绫诲瀷鍚嶇О 璇存槑 瀛樺偍闇€姹?/th>
CHAR(M) 鍥哄畾闀垮害闈炰簩杩涘埗瀛楃涓?/td> M 瀛楄妭锛?<=M<=255
VARCHAR(M) 鍙橀暱闈炰簩杩涘埗瀛楃涓?/td> L+1瀛楄妭锛屽湪姝わ紝L< = M鍜?1<=M<=255
TINYTEXT 闈炲父灏忕殑闈炰簩杩涘埗瀛楃涓?/td> L+1瀛楄妭锛屽湪姝わ紝L<2^8
TEXT 灏忕殑闈炰簩杩涘埗瀛楃涓?/td> L+2瀛楄妭锛屽湪姝わ紝L<2^16
MEDIUMTEXT 涓瓑澶у皬鐨勯潪浜岃繘鍒跺瓧绗︿覆 L+3瀛楄妭锛屽湪姝わ紝L<2^24
LONGTEXT 澶х殑闈炰簩杩涘埗瀛楃涓?/td> L+4瀛楄妭锛屽湪姝わ紝L<2^32
ENUM 鏋氫妇绫诲瀷锛屽彧鑳芥湁涓€涓灇涓惧瓧绗︿覆鍊?/td> 1鎴?涓瓧鑺傦紝鍙栧喅浜庢灇涓惧€肩殑鏁扮洰 (鏈€澶у€间负65535)
SET 涓€涓缃紝瀛楃涓插璞″彲浠ユ湁闆朵釜鎴?澶氫釜SET鎴愬憳 1銆?銆?銆?鎴?涓瓧鑺傦紝鍙栧喅浜庨泦鍚?鎴愬憳鐨勬暟閲忥紙鏈€澶?4涓垚鍛橈級

CHAR(M) 涓哄浐瀹氶暱搴﹀瓧绗︿覆,搴旂敤鍦烘櫙锛氭墜鏈哄彿锛岃韩浠借瘉锛岄摱琛屽崱鍙枫€傘€傘€?/p>

闀垮害鑼冨洿鏄?0~255. 褰撲綘鎯宠鍌ㄥ瓨涓€涓暱搴︿笉瓒?255 鐨勫瓧绗︽椂锛孧ysql 浼氱敤绌烘牸鏉ュ～鍏呭墿涓嬬殑瀛楃

浼樼偣锛氶€熷害蹇?/p>

缂虹偣锛氭氮璐圭┖闂?/p>

VARCHAR锛堬級涓哄彲鍙樺瓧绗︾被鍨?/strong>锛屽瓨鍑犱釜瀛楃锛屽氨鏄嚑涓瓧绗︾殑澶у皬锛屾瘡涓瓧绗﹀墠閮借+1bytes锛屾渶澶у疄闄呴暱搴︾敱鏈€闀跨殑琛岀殑澶у皬鍜屼娇鐢ㄧ殑瀛楃闆嗙‘瀹氾紝鑰屽疄闄呭崰鐢ㄧ殑绌洪棿涓哄瓧绗︿覆鐨勫疄闄呴暱搴﹀姞 1銆?/p>

浼樼偣锛氳妭鐪佺┖闂?/p>

TEXT() 淇濆瓨闈炰簩杩涘埗瀛楃涓诧紝濡傛枃绔犲唴瀹广€佽瘎璁虹瓑銆傚綋淇濆瓨鎴栨煡璇?TEXT 鍒楃殑鍊兼椂锛屼笉鍒犻櫎灏鹃儴绌烘牸銆?/p>

涓?char 鍜?varchar 涓嶅悓鐨勬槸锛宼ext 涓嶅彲浠ユ湁榛樿鍊硷紝鍏舵渶澶ч暱搴︽槸 2 鐨?16 娆℃柟-1

鏃ユ湡绫诲瀷

姣忎竴涓被鍨嬮兘鏈夊悎娉曠殑鍙栧€艰寖鍥达紝褰撴寚瀹氱‘瀹氫笉鍚堟硶鐨勫€兼椂锛岀郴缁熷皢鈥滈浂鈥濆€兼彃鍏ユ暟鎹簱涓€?/p>

绫诲瀷鍚嶇О 鏃ユ湡鏍煎紡 鏃ユ湡鑼冨洿 瀛樺偍闇€姹?/th>
YEAR YYYY 1901 ~ 2155 1 涓瓧鑺?/td>
TIME HH:MM:SS -838:59:59 ~ 838:59:59 3 涓瓧鑺?/td>
DATE YYYY-MM-DD 1000-01-01 ~ 9999-12-3 3 涓瓧鑺?/td>
DATETIME YYYY-MM-DD HH:MM:SS 1000-01-01 00:00:00 ~ 9999-12-31 23:59:59 8 涓瓧鑺?/td>
TIMESTAMP YYYY-MM-DD HH:MM:SS 1980-01-01 00:00:01 UTC ~ 2040-01-19 03:14:07 UTC 4 涓瓧鑺?/td>

date:2019-12-11

datetime:2019-12-11 15:50:55

time:15:50:55

year:2019

timestamp:鏃堕棿鎴?/p>

鏃堕棿鎴冲疄渚嬶細

mysql> insert into t11 values(1,null);
Query OK, 1 row affected (0.04 sec)

mysql> select * from t11;
+------+---------------------+
| id   | create_time         |
+------+---------------------+
|    1 | 2019-12-11 15:53:24 |
+------+---------------------+
create table student(
                id int,
                name varchar(4),
                birth date,
                register datetime,
                work_time year,
                t_time time,
                update_time timestamp
            );

python 鎻掑叆鏃堕棿鏁版嵁鏃讹紝杞垚str绫诲瀷

鏋氫妇闆嗗悎

enum:澶氶€変竴

create table t12(
    id int,
    name varchar(10),
    gender enum('male','female')
);
mysql> insert into t12 values(1,'letin','male');
Query OK, 1 row affected (0.05 sec)

set锛氬閫変竴 鎴?澶氶€夊

create table t13(
    id int,
    name varchar(10),
    hobbies set('swimming','game','study')
);
mysql> insert into t13 values(1,'letin','swimming,game,study');
Query OK, 1 row affected (0.06 sec)

mysql> select * from t13;
+------+-------+---------------------+
| id   | name  | hobbies             |
+------+-------+---------------------+
|    1 | letin | swimming,game,read |
+------+-------+---------------------+
1 row in set (0.00 sec)

绾︽潫鏉′欢

unique灏嗘煇涓瓧娈佃缃负鍞竴鐨勫€?/p>

not + null + unique 鍙樹负涓婚敭

create table t14(
    id int not null unique,  
    name varchar(10)
);
mysql> insert into t14 values(1,'letin');
Query OK, 1 row affected (0.05 sec)

mysql> insert into t14 values(1,'leiting');
ERROR 1062 (23000): Duplicate entry '1' for key 'id'   #id璁剧疆浜嗗敮涓€锛岄噸澶嶅悗浼氭姤閿?/code>

涓婚敭 鑷

primary key-鈥?鈥?鈥?gt;not null unique

涓婚敭灏辨槸琛ㄤ腑鐨勭储寮曪細鍙互閫氳繃绱㈠紩蹇€熸煡鎵炬煇浜涙暟鎹?/p>

涓婚敭绾︽潫鍗冲湪琛ㄤ腑瀹氫箟涓€涓富閿潵鍞竴纭畾琛ㄤ腑姣忎竴琛屾暟鎹殑鏍囪瘑绗︺€備富閿彲浠ユ槸琛ㄤ腑鐨勬煇涓€鍒楁垨鑰呭鍒楃殑缁勫悎锛屽叾涓敱澶氬垪缁勫悎鐨勪富閿О涓哄鍚堜富閿€備富閿簲璇ラ伒瀹堜笅闈㈢殑瑙勫垯锛?/p>

  • 姣忎釜琛ㄥ彧鑳藉畾涔変竴涓富閿€?/li>
  • 涓婚敭鍊煎繀椤诲敮涓€鏍囪瘑琛ㄤ腑鐨勬瘡涓€琛岋紝涓斾笉鑳戒负 NULL锛屽嵆琛ㄤ腑涓嶅彲鑳藉瓨鍦ㄤ袱琛屾暟鎹湁鐩稿悓鐨勪富閿€?/li>

涓婚敭瀹炰緥锛?/p> 

mysql> create table t15(
    -> id int primary key,
    -> name varchar(10)
    -> );
Query OK, 0 rows affected (0.19 sec)

涓婚敭鑷瀹炰緥锛歱rimary key auto_increment

mysql> create table t16(
    -> id int primary key auto_increment,
    -> name varchar(10)
    -> );
Query OK, 0 rows affected (0.20 sec)
mysql> desc t16;
+-------+-------------+------+-----+---------+----------------+
| Field | Type        | Null | Key | Default | Extra          |
+-------+-------------+------+-----+---------+----------------+
| id    | int(11)     | NO   | PRI | NULL    | auto_increment |
| name  | varchar(10) | YES  |     | NULL    |                |
+-------+-------------+------+-----+---------+----------------+
2 rows in set (0.00 sec)

鑷榛樿浠?寮€濮?/p> 

mysql> insert into t16(name) values('letin');
Query OK, 1 row affected (0.04 sec)

mysql> create table t17( -> id int unsigned -> ); Query OK, 0 rows affected (0.19 sec)

鎻掑叆鏁板瓧鏄笉鑳藉甫绗﹀彿

zerofill浣跨敤0濉厖

mysql> create table t18(
    -> id int zerofill
    -> );
Query OK, 0 rows affected (0.22 sec)
mysql> insert into t18 values(100);
Query OK, 1 row affected (0.04 sec)

mysql> select * from t18;
+------------+
| id         |
+------------+
| 0000000100 |
+------------+
1 row in set (0.00 sec)

鍒犻櫎璁板綍

delete 娓呯┖璁板綍,id杩樻槸鎺ョ潃娓呴櫎鍓嶇殑鏁板瓧

mysql> delete from t18;
Query OK, 1 row affected (0.04 sec)

mysql> select * from t18;
Empty set (0.00 sec)

mysql> desc t18;
+-------+---------------------------+------+-----+---------+-------+
| Field | Type                      | Null | Key | Default | Extra |
+-------+---------------------------+------+-----+---------+-------+
| id    | int(10) unsigned zerofill | YES  |     | NULL    |       |
+-------+---------------------------+------+-----+---------+-------+
1 row in set (0.01 sec)

truncate娓呯┖澶氭湁璁板綍锛屽苟涓攊d閲嶇疆涓?

truncate table t20;

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