[Oracle final review] addition, deletion and modification of tablespaces, tables, constraints, indexes and views

establish

1. Table space 
create tablespace spaceName
	datafile 'C:\spaceName.dbf' --  File storage path 
	size 20M  --  Initial size  --  At this point, you can create a table space 
	autoextend on next 5M  --  Automatic growth every time 5M
	maxsize 50M; --  Maximum 50M
--  Add a new data file for the tablespace 
alter tablespace spaceName
    add datafile 'C:\spaceName2.dbf'
    size 10M;
    

2. surface 1
--  Create table  （ And added demonstration constraints ）
create table tableName(
	id number(4) [primary key], --  Field   Field data type 
	name varchar(4) [not null],
    sex char(2) [check (sex in(' male ',' Woman '))], --  Define when you create a table check constraint 
    age number(3) [default '18'], --  The default value is  
    tableId number(4) references tableName2(table2Id) --  This foreign key 
)[tablespace spaceName] --  You can select the specified tablespace 
--  surface 2 To demonstrate foreign keys 
create table tableName2(
    table2Id number(4) [primary key] 
)[tablespace spaceName]

2.1  Add new column （ The table field has been created and you want to add a new field ）
alter table tableName add city varchar(10);-- city  new field name  varchar(10)  data type 

3.  Adding constraints   Don't name constraints oracle Will automatically give a name   It is recommended to name manually 
--  Add constraints to the table fields that have been created 
    --  Primary key primary key
    alter table tableName
    add [constraint pk_id] primary key(id[,name[,...]]);
    -- check constraint   for example   If you want to limit gender, you can only fill in male and female 
    alter table tableName
    add [constraint ck_sex] check (sex in(' male ',' Woman ')); --  The constraint name can be written or not 
    --  Non empty constraint not null constraint 
    alter table tableName modify name not null; --  For the table name Add a non NULL constraint to the field 
    -- unique  constraint   Unique constraint 
    alter table tableName add unique(name);
    --  Foreign keys  foreign key  constraint  ( You need to use the primary key of another table )
    alter table tableName add [constraint fk_tableId] foreign key(tableId) references tableName2(table2Id); --  Of course, the foreign key fields to be specified in different tables can be the same   Here's a demonstration 

4. Create index 
-- 4.1. establish B Tree index 
create  index idx_name on tableName(name) tablespace spaceName; --  For this table name Create a file called ‘idx_name’ Of B Tree index  , B Tree index is the default index 
-- 4.2. Create bitmap index 
create bitmap index idx_sex on tableName(sex) tablespace spaceName;

5. Create view 
--  Create a simple view  （ You only want to display three fields of a table name sex age）
create [or replace] view view_name as select name,sex,age from tableName; 
	-- or replace ：  Replace the existing view if it exists 

modify

1. Table space 
--  Modify the automatic extension of data files 
alter database datafile 'C:\spaceName.dbf' autoextend on next 5M maxsize 100M;
--  Rename a table space 
alter tablespace old_tablespaceName rename to new_tablespaceName;
--  Modify the size of the tablespace data file 
alter database datafile 'C:\spaceName.dbf' resize 100M;
--  The table space has 4 States   modify state 
alter tablespace new_tablespaceName offline/ online/ read only/ read write; --  offline / On-line / read-only / Can read but write   Change to read-only must be online state 
--  Modify the status of the data file   There are three kinds of ：online | offline | offline drop
alter database datafile 'C:\spaceName.dbf' online | offline | offline drop;--  Documents are available | File not available   Used for data files in archive mode |  File not available   Used for data files in non archive mode 

2. surface 
-- 2.1 Change column names  old_col_name  Old field name ,new_col_name： new field name 
alter table tableName rename column old_col_name to new_col_name;
-- 2.2 Modify the data type corresponding to the column  varchar -> varchar2
alter table tableName modify city varchar2;
-- 2.3 rename table  new_col_name :  The new name of the table 
--  The way 1：
alter table tableName rename to new_col_name;
--  The way 2：
rename tableName to new_col_name;
-- 2.4 Move table  （ Move the table to a new table space   If you do not specify the default storage to the default tablespace ） 
-- newSpace  New tablespace name 
alter table tableName move tablespace newSpace;
--  Query whether the move is successful   among tableName It refers to the table name to be queried   Other defaults remain unchanged 
select table_name,tablespace_name from user_tables where table_name = 'tableName';

3.  Indexes 
--  Rename index 
alter index idx_name rename to new_idx_name;
--  Merge index 
alter index new_idx_name coalesce [ deallocate unused]; --  Merge index  [ Free up extra space after merging while merging indexes ]
--  Clear index fragments / Rebuild index 
alter index new_idx_name rebuild; --  Rebuild a new index , Delete the original index 

4.  Update the view 
--  If you only add a field to the original view   Can directly  or replace  Create a new view 
--  In itself orable  According to the base table DML Operation automatically determines the update 

Delete

1. Table space 
-- 1.1 Delete the data file of the tablespace 
alter tablespace spaceName drop datafile 'C:\spaceName2.dbf';
-- 1.2 Delete tablespace 
drop tablespace spaceName |[including contents]|[including contents and datafiles]; --  Delete tablespace spaceName| Keep data files | Delete data files and all contents 

2. surface 
-- 2.1 Delete table 
drop table tableName [cascade constraint][purge] ; --  Delete table [ And delete the view constraint index and trigger of this table ][ Free the occupied resource space immediately after deleting the table ]
-- 2.2 Delete the new column city 
alter table tableName drop column city; 
--  Delete more than one at a time 
alter table tableName drop(city,city1,city2,...)


3. constraint 
--  Delete constraints 
drop constraint constraintName; --  Delete constraint according to constraint name 
	--  Delete primary key constraint primary key
	alter table tableName drop constraint pk_id;
	--  Delete check constraint check 
	alter table tableName drop constraint ck_sex;
	--  Delete non empty constraints not null  front name Field defines a non empty constraint 
	alter table tableName modify name null;
	--  Delete unique constraint unique  front name Fields define unique constraints 
	alter table tableName drop unique(name);
	--  Delete foreign key constraint  foreign key
	alter table tableName drop constraint fk_tableId;
drop index indexName ; --  Delete index 

4. Indexes 
--  Delete index 
drop index  Index name ;

5. View 
drop view viewName ; --  Delete view