create data data _name；

 $conn = mysql_connect(“localhost”,”username”,”password”) or
 die ( “could not connect to localhost”);
 mysql_create_db(“data _name”) or
 die (“could not create data ”);
 $string = “create data data _name”;
 mysql_query( $string) or
 die (mysql_error()); 

use data _name

php: mysql_select_db()

 $conn = mysql_connect(“localhost”,”username”,”password”) or
 die ( “could not connect to localhost”);
 mysql_select_db(“test”,$conn) or
 die (“could not select data ”);

create table table_name

 create table table_name
 (
 column_1 column_type column attributes,
 column_2 column_type column attributes,
 column_3 column_type column attributes,
 primary key (column_name),
 index index_name(column_name)
 )

 $conn = mysql_connect(“localhost”,”username”,”password”) or
 die ( “could not connect to localhost”);
 mysql_select_db(“test”,$conn) or
 die (“could not select data ”);
 $query = “create table my_table (col_1 int not null primary key,
  col_2 text
  )”;
 mysql_query($query) or
 die (mysql_error());

 index index_name(indexed_column) 

 create table table_name type=table_type
 (col_name column attribute);

 alter table table_name

 alter table table_name rename new_table_name

 rename table_name to new_table_name

alter table table_name add column column_name colomn attributes

 alter table my_table add column my_column text not null

alter table my_table add column my_next_col text not null first
alter table my_table add column my_next_col text not null after my_other _column

alter table table_name drop column column name

 alter table table_name add index index_name (column_name1,column_name2,……)
 alter table table_name add unique index_name (column_name)
 alter table table_name add primary key(my_column)
 alter table table_name drop index index_name

alter table_name test10 drop primary key

 alter table table_name change original_column_name new_column_name int not null

 alter table table_name modify col_1 clo_1 varchar(200) 

 insert into table_name (column_1,column_2,column_3,…..)
 values (value1,value2,value3,……)

insert into table_name (text_col,int_col) value (\'hello world\',1)

 updata table_name set col__1=vaule_1,col_1=vaule_1 where col=vaule

 drop table table_name
 drop data data _name

 show columns from table_name
 show fields from table_name

 select column_1,column_2,column_3 from table_name

 select * from table_name

 select * from table_name where user_id = 2

select * from users where city = ‘San Francisco'

 select * from users where userid=1 or city='San Francisco'
 select 8 from users where state='CA' and city='San Francisco'

 select * from users where zip!='1111′ or zip='1111′ or zip is null

 select * from table_name where zip is not null

 select distinct city,state from users where state='CA'

 select * from users where lastchanged between 20000614000000 and 20000614235959
 select * from users where lname between ‘a' and ‘m'

 select * from users where state='RI' or state='NH' or state='VT' or state='MA' or state='ME'

select * from users where state in (‘RI','NH','VY','MA','ME') 

 select * from user where state not in (‘RI','NH','VT','MA','ME')

 select * from users where fname like ‘Dan%' %匹配零个字符
 select * from users where fname like ‘J___' 匹配以J开头的任意三字母词

 select * from users order by lname,fname

 select * from users order by lname asc, fname desc

 select * from users limit 0,5
  select * from users order by lname,fname limit 0,5

  select * from users limit 5,5

 select state,count(*) from users group by state

 select count(*) from users

select * from companies,contacts where companies.company_ID=contacts.company_ID