1. 常見命令
連接本地?cái)?shù)據(jù)庫(kù)與遠(yuǎn)程數(shù)據(jù)庫(kù)(172.16.xx.xx:3306):
mysql -h localhost -u root -p123 mysql -h 172.16.xx.xx -P 3306 -u root -p
2. DDL
數(shù)據(jù)定義語言(Data Definition Lanuage, DDL)定義了數(shù)據(jù)庫(kù)模式,包括CREATE、ALTER、DROP、TRUNCATE、COMMENT與RENAME語句。
創(chuàng)建(CREATE)
create語句創(chuàng)建了一張表:
CREATE TABLE `device_label` ( `id` int(11) NOT NULL AUTO_INCREMENT COMMENT '主鍵-自增長(zhǎng)ID', `origin_model` varchar(64) COLLATE utf8_bin NOT NULL COMMENT '收集機(jī)型', `origin_vendor` varchar(64) COLLATE utf8_bin NOT NULL COMMENT '收集廠商', `vendor` varchar(32) COLLATE utf8_bin NOT NULL COMMENT '標(biāo)注廠商', `model` varchar(32) COLLATE utf8_bin NOT NULL COMMENT '標(biāo)注品牌', PRIMARY KEY (`id`), UNIQUE KEY `device_key` (`origin_model`,`origin_vendor`) ) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8 COLLATE=utf8_bin COMMENT='設(shè)備標(biāo)注表'; 改(ALTER)
ALTER TABLE改變了表的結(jié)構(gòu),支持如下操作,
修改列類型與列名:
alter table device_label modify origin_model varchar(32); alter table device_label change origin_model device_model varchar(16);
追加列:
alter table device_label add os_type varchar(8) COLLATE utf8_bin NOT NULL COMMENT '操作系統(tǒng)' after id;
修改列之間的順序:
alter table device_label modify os_type varchar(8) after origin_model;
修改primary key:
alter table device_label drop primary key, add primary key (`origin_model`,`origin_vendor`);
清空(TRUNCATE)
TRUNCATE為清空表,相當(dāng)于delete from 不指定where條件。
truncate device_label;
3. DCL
數(shù)據(jù)控制語言(Data Control Language, DCL)用于用戶權(quán)限的管理,包括了GRANT與REVOKE命令。
授權(quán)(GRANT)
MySQL有很精細(xì)的權(quán)限控制:
?細(xì)致的權(quán)限分類
?DB -> 表 -> 列,權(quán)限的粗細(xì)粒度
?對(duì)host(可通配符匹配)控制
創(chuàng)建hive用戶,并賦予以localhost訪問 db1 所有表的權(quán)限:
CREATE USER 'hive'@'localhost' IDENTIFIED BY 'mypass'; GRANT ALL ON db1.* TO 'hive'@'localhost'; -- 可簡(jiǎn)寫為 GRANT ALL ON db1.* TO 'hive'@'localhost' IDENTIFIED BY 'mypass';
也可以只賦予某個(gè)表的select權(quán)限:
GRANT SELECT ON db2.invoice TO 'hive'@'localhost';
4. DML
數(shù)據(jù)定義語言(Data manipulation language, DML)主要用于表達(dá)數(shù)據(jù)庫(kù)的查詢與更新,主要包括增刪改查(INSERT,UPDATE,DELETE,SELECT)。
增(INSERT)
增加行數(shù)據(jù):
insert into device_label (origin_model, origin_vendor, vendor, model) values ( 'h9', 'bbk', '步步高', 'H9' );
復(fù)制一個(gè)表到另外一個(gè)表:
insert into device_label_copy (`origin_model`, `origin_vendor`, `vendor`, `model`) select `origin_model`, `origin_vendor`, `vendor`, `model` from device_label;
此外,MySQL支持以load data方式將結(jié)構(gòu)化的純文本入庫(kù):
load data local infile 'dvc-label.csv' into table device_label fields terminated by ',' ignore 1 lines (origin_model, origin_vendor, vendor, model);
若出現(xiàn)ERROR 1148 (42000)錯(cuò)誤,則用mysql –local-infile -u user -ppasswd 命令進(jìn)入mysql。
改(UPDATE)
更新列的值:
update device_label set origin_model = 't2', origin_vendor = 'xiami' where vendor = '錘子';
刪(DELETE)
根據(jù)where條件刪除行:
delete from device_label where origin_vendor = 'alps';
查(SELECT)
查詢標(biāo)注機(jī)型數(shù)超過10的廠商:
select vendor, count(distinct model) as models from device_label group by vendor having models > 10
以上所述是小編給大家介紹的mysql常用基本sql語句總結(jié),希望對(duì)大家有所幫助,如果大家有任何疑問請(qǐng)給我留言,小編會(huì)及時(shí)回復(fù)大家的。在此也非常感謝大家對(duì)網(wǎng)站的支持!