һЩ»ù±¾µÄSQLÃüÁî

--ÏÔʾ°æ±¾ºÅ£¬µ±Ç°ÈÕÆÚ
SELECT VERSION(),CURRENT_DATE(),NOW();
--Ãâ·ÑµÄ¼ÆËãÆ÷
SELECT (20+5)*4 AS RESULT,SIN(PI()/3);
--´´½¨Êý¾Ý¿â
CREATE DATABASE databasename;
--ɾ³ýÊý¾Ý¿â
DROP DATABASE databasename;
--ÏÔʾµ±Ç°´æÔÚµÄÊý¾Ý¿â
SHOW DATABASES;
--Ñ¡ÔñÊý¾Ý¿â
USE databasename;
--ÏÔʾµ±Ç°Ñ¡ÔñµÄÊý¾Ý¿â
SELECT DATABASE(), USER();
--ÏÔʾµ±Ç°Êý¾Ý¿âÖеıí
SHOW TABLES;
--²åÈë±í
CREATE TABLE tablename
(
id varchar(32) not null primary key,
name varchar(20) not null,
password varchar(20) not null

);
--²åÈëÊý¾Ý
INSERT INTO tablename VALUES ('CZX','Christen','litejava');
--µ¼Èë½Å±¾
SOURCE filepath; -- eg SOURCE C:/blog.sql
--ɾ³ý±í
DROP TABLE tablename;
--ɾ³ý±íÖеÄÈ«²¿Êý¾Ý
DELETE from tablename;
--¸üÐÂÊý¾Ý
UPDATE tablename SET password='123456';
--ÏÔʾ±íµÄÄÚÈÝ
SELECT * from tablename;
--ÃèÊö±íµÄ½á¹¹
DESCRIBE tablename;
--´ÓÎı¾Öе¼ÈëÊý¾Ý
LOAD DATA LOCAL INFILE 'file path' INTO TABLE tablename;
--Ñ¡ÔñÌØÊâÐÐ
SELECT * from tablename WHERE id = 'czx';
SELECT name,password from tablename WHERE id = 'czx' AND name = 'Christen'
SELECT * from tablename WHERE name IS NULL;
--È¥³ýÖظ´ÐÐ
SELECT DISTINCT name from tablename;
--Ä£ºý²éѯ
SELECT * from tablename WHERE name LIKE '%³Â×ÔÐÂ%';
--¼ÆÊý
SELECT COUNT(*) from tablename;
#°´Ìõ¼þ¹ýÂË
SELECT * from T_Employee WHERE FSalary>4000 AND FSalary<8000
SELECT * from T_Employee WHERE FSalary BETWEEN 4000 AND 8000
#ÅÅÐòascÉýÐò,desc½µÐò
#select * from info order by wage desc
#select * from info order by name asc
#Ä£ºý²éѯ
#SELECT address from info where t_name like '%c%'
#²åÈëÒ»ÁÐ
#alter table info add t_phone varchar(24) null
#ÇóºÍsum,max,min,avg
#select sum(c_2) from tablename
ÏÔʾÊý¾Ý¿â»ò±í:
    show databases;
    use database_name;
    show tables;
¸ü¸Ä±íÃû:
&