Mysql資料庫：DDL語言

MySQL绛夎蔣浠跺彲浠ユ帴鍙楀懡浠わ紝骞跺仛鍑虹浉搴旂殑鎿嶄綔锛岀敱浜庡懡浠や腑鍙互鍖呭惈鍒犻櫎鏂囦歡銆佽幏鍙栨枃浠跺唴瀹圭瓑浼楀鎿嶄綔锛屽浜庣紪鍐欑殑鍛戒護灏辨槸鏄疭QL璇彞銆?

涓昏鍔熻兘锛?

• 灏嗘暟鎹繚瀛樺埌鏂囦歡鎴栧唴瀛?/li>
• 鎺ユ敹鐗瑰畾鐨勫懡浠わ紝鐒跺悗瀵規枃浠惰繘琛岀浉搴旂殑鎿嶄綔

DDL锛圖ata Definition Language鏁版嵁瀹氫箟璇█锛?/h2>

鏁版嵁搴撶殑鍒涘緩

1. 鏄劇ず鏁版嵁搴?/li>

show databases
           

2. 鍒涘緩鏁版嵁搴?

create  database   鏁版嵁搴撳悕绉?           

姣斿鍒涘緩涓€涓?offcn 鐨勬暟鎹簱锛?

鍒涘緩瀛楃闆嗕負gbk 鐨刴ydb2鏁版嵁搴擄細create database mydb2 character set gbk; 鎴栬€卌reate database mydb2 charset=gbk;
淇敼鏁版嵁搴搈ydb2 瀛楃闆嗕負utf8----> alter database mydb2 character set utf8;
           

3. 鎵撳紑鏁版嵁搴?

use  鏁版嵁搴撳悕绉?           

娉細姣忔浣跨敤鏁版嵁搴撳繀椤繪墦寮€鐩稿簲鏁版嵁搴擄紝灏ゅ叾鍦ㄥ垱寤鴻〃鐨勬椂鍊欍€?

1. 鏌ョ湅鏁版嵁搴撳垱寤虹殑缁嗚妭

show  create  database  鏁版嵁搴撳悕绉?           

5. 鏌ョ湅褰撳墠姝ｅ湪浣跨敤鐨勬暟鎹簱

select  database();
           

鏁版嵁琛ㄧ殑鍒涘緩

1. 鏄劇ず琛ㄦ牸

show  tables;
           

1. 鍒涘緩琛ㄦ牸

create  table  琛ㄥ悕 锛堝垪鍚? 鏁版嵁绫誨瀷 锛屽垪鍚? 鏁版嵁绫誨瀷  锛?           

渚嬪

create table students(id int,name varchar(20),age int, phone char(11),height float(5,2));
           

char鏁版嵁绫誨瀷鐢ㄤ簬琛ㄧず鍥哄畾闀垮害鐨勫瓧绗︿覆锛屽彲浠ュ寘鍚渶澶氳揪255涓瓧绗︺€傚叾涓璵浠ｈ〃瀛楃涓茬殑闀垮害銆? PS: 鍗充嬌鏁版嵁灏忎簬m闀垮害锛屼篃浼氬崰鐢╩闀垮害

varchars鏁版嵁绫誨瀷鐢ㄤ簬鍙橀暱鐨勫瓧绗︿覆锛屽彲浠ュ寘鍚渶澶氳揪255涓瓧绗︺€傚叾涓璵浠ｈ〃璇ユ暟鎹被鍨嬫墍鍏佽淇濆瓨鐨勫瓧绗︿覆鐨勬渶澶ч暱搴︼紝鍙闀垮害灏忎簬璇ユ渶澶у€肩殑瀛楃涓查兘鍙互琚繚瀛樺湪璇ユ暟鎹被鍨嬩腑銆?

娉細铏界劧varchar浣跨敤璧鋒潵杈冧負鐏墊椿锛屼絾鏄粠鏁翠釜绯葷粺鐨勬€ц兘瑙掑害鏉ヨ锛宑har鏁版嵁绫誨瀷鐨勫鐞嗛€熷害鏇村揩锛屾湁鏃剁敋鑷沖彲浠ヨ秴鍑簐archar澶勭悊閫熷害鐨?0%銆傚洜姝わ紝鐢ㄦ埛鍦ㄨ璁℃暟鎹簱鏃跺簲褰撶患鍚堣€冭檻鍚勬柟闈㈢殑鍥犵礌锛屼互姹傝揪鍒版渶浣崇殑骞寵　

1. 鍒犻櫎琛ㄦ牸

drop   table   琛ㄥ悕
           

1. 娓呯┖琛ㄦ牸

delete   from  琛ㄥ悕
           

1. 鍚戣〃鏍間腑鎻掑叆鏁版嵁

insert  into 琛ㄥ悕  values (    )
           

insert  into student  values (1,'ls','man');
           

6.鏌ョ湅琛ㄦ牸涓殑鎵€鏈夌殑璁闆綍

select  * from   琛ㄥ悕
           

1. 鏌ョ湅琛ㄦ牸缁撴瀯

desc   琛ㄦ牸鍚嶇О
           

1. 鏌ョ湅鍒涘緩琛ㄦ牸 鐨勭粏鑺?/li>

show create  table  琛ㄦ牸鍚嶇О
           

1. 淇敼琛ㄦ牸

娣誨姞瀛楁-->>alter table 琛ㄥ悕 add 瀛楁鍚?鏁版嵁绫誨瀷;
淇敼瀛楁鐨勬暟鎹被鍨?->> alter table 琛ㄥ悕 modify 瀛楁鍚?鏂扮殑鏁版嵁绫誨瀷;
淇敼瀛楁鍚?->> alter table 琛ㄥ悕 change 鏃у瓧娈?鏂闆瓧娈?鏂闆瓧娈電殑鏁版嵁绫誨瀷;
鍒犻櫎瀛楁 -->> alter table 琛ㄥ悕 drop 瀛楁鍚?
淇敼琛ㄦ牸瀛楃闆?->> alter table 琛ㄥ悕 character set 瀛楃闆? 鎴栬€卆lter table 琛ㄥ悕  charset= 瀛楃闆?
淇敼琛ㄥ悕-->> alter table 琛ㄥ悕 rename to 鏂拌〃鍚?鎴栬€?rename table 鏃ц〃鍚?to 鏂拌〃鍚?
鍒犻櫎琛ㄦ牸-->> drop table 琛ㄥ悕;
鍒犻櫎鏁版嵁搴?-->> drop database 鏁版嵁搴撳悕;