Замечание
Документация находится в процессе перевода и может отставать от английской версии.
Вложенный модуль box.schema¶
Общие сведения¶
The box.schema
submodule has data-definition functions
for spaces, users, roles, function tuples, and sequences.
Индекс¶
Below is a list of all box.schema
functions.
Name | Use |
---|---|
box.schema.space.create() | Create a space |
box.schema.user.create() | Create a user |
box.schema.user.drop() | Drop a user |
box.schema.user.exists() | Check if a user exists |
box.schema.user.grant() | Grant privileges to a user or a role |
box.schema.user.revoke() | Revoke privileges from a user or a role |
box.schema.user.password() | Get a hash of a user’s password |
box.schema.user.passwd() | Associate a password with a user |
box.schema.user.info() | Get a description of a user’s privileges |
box.schema.role.create() | Create a role |
box.schema.role.drop() | Drop a role |
box.schema.role.exists() | Check if a role exists |
box.schema.role.grant() | Grant privileges to a role |
box.schema.role.revoke() | Revoke privileges from a role |
box.schema.role.info() | Get a description of a role’s privileges |
box.schema.func.create() | Create a function tuple |
box.schema.func.drop() | Drop a function tuple |
box.schema.func.exists() | Check if a function tuple exists |
box.schema.sequence.create() | Create a new sequence generator |
sequence_object:next() | Generate and return the next value |
sequence_object:alter() | Change sequence options |
sequence_object:reset() | Reset sequence state |
sequence_object:set() | Set the new value |
sequence_object:drop() | Drop the sequence |
space_object:create_index() | Create an index |
-
box.schema.space.
create
(space-name[, {options}])¶ Create a space.
Параметры: - space-name (string) – name of space, which should conform to the rules for object names
- options (table) – see «Options for box.schema.space.create» chart, below
Return: space object
Rtype: userdata
Options for box.schema.space.create
Name Эффект Type Default temporary space contents are temporary: changes are not stored in the write-ahead log and there is no replication. Note re storage engine: vinyl does not support temporary spaces. boolean false id unique identifier: users can refer to spaces with the id instead of the name number last space’s id, +1 field_count fixed count of fields: for example if field_count=5, it is illegal to insert a tuple with fewer than or more than 5 fields number 0 i.e. not fixed if_not_exists create space only if a space with the same name does not exist already, otherwise do nothing but do not cause an error boolean false engine „memtx“ or „vinyl“ string „memtx“ user name of the user who is considered to be the space’s owner for authorization purposes string current user’s name format field names and types: See the illustrations of format clauses in the space_object:format() description and in the box.space._space example. Optional and usually not specified. table (blank) There are three syntax variations for object references targeting space objects, for example
box.schema.space.drop(space-id)
will drop a space. However, the common approach is to use functions attached to the space objects, for example space_object:drop().Пример
tarantool> s = box.schema.space.create('space55') --- ... tarantool> s = box.schema.space.create('space55', { > id = 555, > temporary = false > }) --- - error: Space 'space55' already exists ... tarantool> s = box.schema.space.create('space55', { > if_not_exists = true > }) --- ...
After a space is created, usually the next step is to create an index for it, and then it is available for insert, select, and all the other box.space functions.
-
box.schema.user.
create
(user-name[, {options}])¶ Create a user. For explanation of how Tarantool maintains user data, see section Users and reference on _user space.
The possible options are:
if_not_exists
=true|false
(default =false
) - boolean;true
means there should be no error if the user already exists,password
(default = „“) - string; thepassword
= password specification is good because in a URI (Uniform Resource Identifier) it is usually illegal to include a user-name without a password.
Примечание
The maximum number of users is 32.
Параметры: - user-name (string) – name of user, which should conform to the rules for object names
- options (table) –
if_not_exists
,password
Return: nil
Примеры:
box.schema.user.create('Lena') box.schema.user.create('Lena', {password = 'X'}) box.schema.user.create('Lena', {if_not_exists = false})
-
box.schema.user.
drop
(user-name[, {options}])¶ Drop a user. For explanation of how Tarantool maintains user data, see section Users and reference on _user space.
Параметры: Примеры:
box.schema.user.drop('Lena') box.schema.user.drop('Lena',{if_exists=false})
-
box.schema.user.
exists
(user-name)¶ Return
true
if a user exists; returnfalse
if a user does not exist. For explanation of how Tarantool maintains user data, see section Users and reference on _user space.Параметры: - user-name (string) – the name of the user
Rtype: bool
Example:
box.schema.user.exists('Lena')
-
box.schema.user.
grant
(user-name, privileges, object-type, object-name[, {options}])¶ -
box.schema.user.
grant
(user-name, privileges, 'universe'[, nil, {options}]) -
box.schema.user.
grant
(user-name, role-name[, nil, nil, {options}]) Grant privileges to a user or to another role.
Параметры: - user-name (string) – the name of the user.
- privileges (string) – „read“ or „write“ or „execute“ or „create“ or „alter“ or „drop“ or a combination.
- object-type (string) – „space“ or „function“ or „sequence“.
- object-name (string) – name of object to grant permissions to.
- role-name (string) – name of role to grant to user.
- options (table) –
grantor
,if_not_exists
.
If
'function','object-name'
is specified, then a _func tuple with that object-name must exist.Variation: instead of
object-type, object-name
say „universe“ which means „all object-types and all objects“. In this case, object name is omitted.Variation: instead of
privilege, object-type, object-name
sayrole-name
(see section Roles).The possible options are:
grantor
= grantor_name_or_id – string or number, for custom grantor,if_not_exists
=true|false
(default =false
) - boolean;true
means there should be no error if the user already has the privilege.
Example:
box.schema.user.grant('Lena', 'read', 'space', 'tester') box.schema.user.grant('Lena', 'execute', 'function', 'f') box.schema.user.grant('Lena', 'read,write', 'universe') box.schema.user.grant('Lena', 'Accountant') box.schema.user.grant('Lena', 'read,write,execute', 'universe') box.schema.user.grant('X', 'read', 'universe', nil, {if_not_exists=true}))
-
box.schema.user.
revoke
(user-name, privilege, object-type, object-name)¶ -
box.schema.user.
revoke
(user-name, role-name) Revoke privileges from a user or from another role.
Параметры: The user must exist, and the object must exist, but it is not an error if the user does not have the privilege.
Variation: instead of
object-type, object-name
say „universe“ which means „all object-types and all objects“.Variation: instead of
privilege, object-type, object-name
sayrole-name
(see section Roles).Example:
box.schema.user.revoke('Lena', 'read', 'space', 'tester') box.schema.user.revoke('Lena', 'execute', 'function', 'f') box.schema.user.revoke('Lena', 'read,write', 'universe') box.schema.user.revoke('Lena', 'Accountant')
-
box.schema.user.
password
(password)¶ Return a hash of a user’s password. For explanation of how Tarantool maintains passwords, see section Passwords and reference on _user space.
Примечание
- If a non-„guest“ user has no password, it’s impossible to connect to Tarantool using this user. The user is regarded as “internal” only, not usable from a remote connection. Such users can be useful if they have defined some procedures with the SETUID option, on which privileges are granted to externally-connectable users. This way, external users cannot create/drop objects, they can only invoke procedures.
- For the „guest“ user, it’s impossible to set a password: that would be misleading, since „guest“ is the default user on a newly-established connection over a binary port, and Tarantool does not require a password to establish a binary connection. It is, however, possible to change the current user to ‘guest’ by providing the AUTH packet with no password at all or an empty password. This feature is useful for connection pools, which want to reuse a connection for a different user without re-establishing it.
Параметры: - password (string) – password to be hashed
Rtype: string
Example:
box.schema.user.password('ЛЕНА')
-
box.schema.user.
passwd
([user-name, ]password)¶ Associate a password with the user who is currently logged in, or with the user specified by user-name. The user must exist and must not be „guest“.
Users who wish to change their own passwords should use
box.schema.user.passwd(password)
syntax.Administrators who wish to change passwords of other users should use
box.schema.user.passwd(user-name, password)
syntax.Параметры: Example:
box.schema.user.passwd('ЛЕНА') box.schema.user.passwd('Lena', 'ЛЕНА')
-
box.schema.user.
info
([user-name])¶ Return a description of a user’s privileges. For explanation of how Tarantool maintains user data, see section Users and reference on _user space.
Параметры: - user-name (string) – the name of the user. This is optional; if it is not supplied, then the information will be for the user who is currently logged in.
Example:
box.schema.user.info() box.schema.user.info('Lena')
-
box.schema.role.
create
(role-name[, {options}])¶ Create a role. For explanation of how Tarantool maintains role data, see section Roles.
Параметры: - role-name (string) – name of role, which should conform to the rules for object names
- options (table) –
if_not_exists
=true|false
(default =false
) - boolean;true
means there should be no error if the role already exists
Return: nil
Example:
box.schema.role.create('Accountant') box.schema.role.create('Accountant', {if_not_exists = false})
-
box.schema.role.
drop
(role-name[, {options}])¶ Drop a role. For explanation of how Tarantool maintains role data, see section Roles.
Параметры: Example:
box.schema.role.drop('Accountant')
-
box.schema.role.
exists
(role-name)¶ Return
true
if a role exists; returnfalse
if a role does not exist.Параметры: - role-name (string) – the name of the role
Rtype: bool
Example:
box.schema.role.exists('Accountant')
-
box.schema.role.
grant
(role-name, privilege, object-type, object-name[, option])¶ -
box.schema.role.
grant
(role-name, privilege, 'universe'[, nil, option]) -
box.schema.role.
grant
(role-name, role-name[, nil, nil, option]) Grant privileges to a role.
Параметры: - role-name (string) – the name of the role.
- privilege (string) – „read“ or „write“ or „execute“ or „create“ or „alter“ or „drop“ or a combination.
- object-type (string) – „space“ or „function“ or „sequence“.
- object-name (string) – the name of a function or space or sequence.
- option (table) –
if_not_exists
=true|false
(default =false
) - boolean;true
means there should be no error if the role already has the privilege.
The role must exist, and the object must exist.
Variation: instead of
object-type, object-name
say „universe“ which means „all object-types and all objects“.Variation: instead of
privilege, object-type, object-name
sayrole-name
– to grant a role to a role.Example:
box.schema.role.grant('Accountant', 'read', 'space', 'tester') box.schema.role.grant('Accountant', 'execute', 'function', 'f') box.schema.role.grant('Accountant', 'read,write', 'universe') box.schema.role.grant('public', 'Accountant') box.schema.role.grant('role1', 'role2', nil, nil, {if_not_exists=false})
-
box.schema.role.
revoke
(role-name, privilege, object-type, object-name)¶ Revoke privileges from a role.
Параметры: The role must exist, and the object must exist, but it is not an error if the role does not have the privilege.
Variation: instead of
object-type, object-name
say „universe“ which means „all object-types and all objects“.Variation: instead of
privilege, object-type, object-name
sayrole-name
.Example:
box.schema.role.revoke('Accountant', 'read', 'space', 'tester') box.schema.role.revoke('Accountant', 'execute', 'function', 'f') box.schema.role.revoke('Accountant', 'read,write', 'universe') box.schema.role.revoke('public', 'Accountant')
-
box.schema.role.
info
(role-name)¶ Return a description of a role’s privileges.
Параметры: - role-name (string) – the name of the role.
Example:
box.schema.role.info('Accountant')
-
box.schema.func.
create
(func-name[, {options}])¶ Create a function tuple. This does not create the function itself – that is done with Lua – but if it is necessary to grant privileges for a function, box.schema.func.create must be done first. For explanation of how Tarantool maintains function data, see reference on _func space.
The possible options are:
if_not_exists
=true|false
(default =false
) - boolean;true
means there should be no error if the_func
tuple already exists.setuid
=true|false
(default = false) - withtrue
to make Tarantool treat the function’s caller as the function’s creator, with full privileges. Remember that SETUID works only over binary ports. SETUID doesn’t work if you invoke a function via an admin console or inside a Lua script.language
= „LUA“|“C“ (default = ‘LUA’).
Параметры: - func-name (string) – name of function, which should conform to the rules for object names
- options (table) –
if_not_exists
,setuid
,language
.
Return: nil
Example:
box.schema.func.create('calculate') box.schema.func.create('calculate', {if_not_exists = false}) box.schema.func.create('calculate', {setuid = false}) box.schema.func.create('calculate', {language = 'LUA'})
-
box.schema.func.
drop
(func-name[, {options}])¶ Drop a function tuple. For explanation of how Tarantool maintains function data, see reference on _func space.
Параметры: Example:
box.schema.func.drop('calculate')
-
box.schema.func.
exists
(func-name)¶ Return true if a function tuple exists; return false if a function tuple does not exist.
Параметры: - func-name (string) – the name of the function
Rtype: bool
Example:
box.schema.func.exists('calculate')
-
box.schema.func.
reload
([name])¶ Reload a C module or function without restarting the server.
Under the hood, Tarantool loads a new copy of the module (
*.so
shared library) and starts routing all new request to the new version. The previous version remains active until all started calls are finished. All shared libraries are loaded withRTLD_LOCAL
(see «man 3 dlopen»), therefore multiple copies can co-exist without any problems.Примечание
- When a function from a certain module is reloaded, all the other functions from this module are also reloaded.
- Reload will fail if a module was loaded from Lua script with ffi.load().
Параметры: - name (string) – the name of the module or function to reload
Примеры:
-- reload a function box.schema.func.reload('module.function') -- reload the entire module contents box.schema.func.reload('module') -- reload everything box.schema.func.reload()
Sequences¶
An introduction to sequences is in the Sequences section of the «Data model» chapter. Here are the details for each function and option.
-
box.schema.sequence.
create
(name[, options])¶ Create a new sequence generator.
Параметры: Return: a reference to a new sequence object.
Options:
start
– the STARTS WITH value. Type = integer, Default = 1.min
– the MINIMUM value. Type = integer, Default = 1.max
- the MAXIMUM value. Type = integer, Default = 9223372036854775807.There is a rule:
min
<=start
<=max
. For example it is illegal to say{start=0}
because then the specified start value (0) would be less than the default min value (1).There is a rule:
min
<= next-value <=max
. For example, if the next generated value would be 1000, but the maximum value is 999, then that would be considered «overflow».cycle
– the CYCLE value. Type = bool. Default = false.If the sequence generator’s next value is an overflow number, it causes an error return – unless
cycle == true
.But if
cycle == true
, the count is started again, at the MINIMUM value or at the MAXIMUM value (not the STARTS WITH value).cache
– the CACHE value. Type = unsigned integer. Default = 0.Currently Tarantool ignores this value, it is reserved for future use.
step
– the INCREMENT BY value. Type = integer. Default = 1.Ordinarily this is what is added to the previous value.
-
sequence_object:
next
()¶ Generate the next value and return it.
The generation algorithm is simple:
- If this is the first time, then return the STARTS WITH value.
- If the previous value plus the INCREMENT value is less than the
MINIMUM value or greater than the MAXIMUM value, that is «overflow»,
so either return an error (if
cycle
=false
) or return the MAXIMUM value (ifcycle
=true
andstep
< 0) or return the MINIMUM value (ifcycle
=true
andstep
> 0).
If there was no error, then save the returned result, it is now the «previous value».
For example, suppose sequence „S“ has:
min
== -6,max
== -1,step
== -3,start
= -2,cycle
= true,- previous value = -2.
Then
box.sequence.S:next()
returns -5 because -2 + (-3) == -5.Then
box.sequence.S:next()
again returns -1 because -5 + (-3) < -6, which is overflow, causing cycle, andmax
== -1.This function requires a „write“ privilege on the sequence.
Примечание
This function should not be used in «cross-engine» transactions (transactions which use both the memtx and the vinyl storage engines).
To see what the previous value was, without changing it, you can select from the _sequence_data system space.
-
sequence_object:
alter
(options)¶ The
alter()
function can be used to change any of the sequence’s options. Requirements and restrictions are the same as for box.schema.sequence.create().
-
sequence_object:
reset
()¶ Set the sequence back to its original state. The effect is that a subsequent
next()
will return thestart
value. This function requires a „write“ privilege on the sequence.
-
sequence_object:
set
(new-previous-value)¶ Set the «previous value» to
new-previous-value
. This function requires a „write“ privilege on the sequence.
-
sequence_object:
drop
()¶ Drop an existing sequence.
Example:
Here is an example showing all sequence options and operations:
s = box.schema.sequence.create( 'S2', {start=100, min=100, max=200, cache=100000, cycle=false, step=100 }) s:alter({step=6}) s:next() s:reset() s:set(150) s:drop()
-
space_object:
create_index
(... [sequence='...' option] ...)¶ You can use the
sequence=sequence-name
(orsequence=sequence-id
orsequence=true
) option when creating or altering a primary-key index. The sequence becomes associated with the index, so that the nextinsert()
will put the next generated number into the primary-key field, if the field would otherwise be nil.For example, if „Q“ is a sequence and „T“ is a new space, then this will work:
tarantool> box.space.T:create_index('Q',{sequence='Q'}) --- - unique: true parts: - type: unsigned is_nullable: false fieldno: 1 sequence_id: 8 id: 0 space_id: 514 name: Q type: TREE ...
(Notice that the index now has a
sequence_id
field.)And this will work:
tarantool> box.space.T:insert{nil,0} --- - [1, 0] ...
Примечание
If you are using negative numbers for the sequence options, make sure that the index key type is „integer“. Otherwise the index key type may be either „integer“ or „unsigned“.
A sequence cannot be dropped if it is associated with an index.