Создаем свою первую базу данных на Tarantool

Example on GitHub: create_db

In this tutorial, you create a Tarantool database, write data to it, and select data from this database.

Prerequisites

Before starting this tutorial:

Install the tt utility.
Install Tarantool.

Примечание

The tt utility provides the ability to install Tarantool software using the tt install command.

Creating an application

The tt create command can be used to create an application from a predefined or custom template. In this tutorial, the application layout is prepared manually:

Create a tt environment in the current directory using the tt init command.
Inside the instances.enabled directory of the created tt environment, create the create_db directory.
Inside instances.enabled/create_db, create the instances.yml and config.yaml files:
- instances.yml specifies instances to run in the current environment. In this example, there is one instance:
```
instance001:
```
- config.yaml contains basic instance configuration:
```
groups:
  group001:
    replicasets:
      replicaset001:
        instances:
          instance001:
            iproto:
              listen:
              - uri: '127.0.0.1:3301'
```
  The instance in the configuration accepts incoming requests on the 3301 port.

Working with the database

Starting an instance

Start the Tarantool instance from the tt environment directory using tt start:
```
$ tt start create_db
```

To check the running instance, use the tt status command:

$ tt status create_db
INSTANCE                       STATUS      PID   MODE
create_db:instance001          RUNNING     54560 RW

Connect to the instance with tt connect:
```
$ tt connect create_db:instance001
   • Connecting to the instance...
   • Connected to create_db:instance001

create_db:instance001>
```
This command opens an interactive Tarantool console with the create_db:instance001> prompt. Now you can enter requests in the command line.

Creating a space

Create a space named bands:

create_db:instance001> box.schema.space.create('bands')
---
- engine: memtx
  before_replace: 'function: 0x010229d788'
  field_count: 0
  is_sync: false
  is_local: false
  on_replace: 'function: 0x010229d750'
  temporary: false
  index: []
  type: normal
  enabled: false
  name: bands
  id: 512
- created
...

Форматируйте созданный спейс, указывая имена и типы полей:

create_db:instance001> box.space.bands:format({
                           { name = 'id', type = 'unsigned' },
                           { name = 'band_name', type = 'string' },
                           { name = 'year', type = 'unsigned' }
                       })
---
...

Creating indexes

Create the primary index based on the id field:

create_db:instance001> box.space.bands:create_index('primary', { parts = { 'id' } })
---
- unique: true
  parts:
  - fieldno: 1
    sort_order: asc
    type: unsigned
    exclude_null: false
    is_nullable: false
  hint: true
  id: 0
  type: TREE
  space_id: 512
  name: primary
...

Create the secondary index based on the band_name field:

create_db:instance001> box.space.bands:create_index('secondary', { parts = { 'band_name' } })
---
- unique: true
  parts:
  - fieldno: 2
    sort_order: asc
    type: string
    exclude_null: false
    is_nullable: false
  hint: true
  id: 1
  type: TREE
  space_id: 512
  name: secondary
...

Writing and selecting data

Insert three tuples into the space:

create_db:instance001> box.space.bands:insert { 1, 'Roxette', 1986 }
---
- [1, 'Roxette', 1986]
...
create_db:instance001> box.space.bands:insert { 2, 'Scorpions', 1965 }
---
- [2, 'Scorpions', 1965]
...
create_db:instance001> box.space.bands:insert { 3, 'Ace of Base', 1987 }
---
- [3, 'Ace of Base', 1987]
...

Select a tuple using the primary index:

create_db:instance001> box.space.bands:select { 3 }
---
- - [3, 'Ace of Base', 1987]
...

Select tuples using the secondary index:

create_db:instance001> box.space.bands.index.secondary:select{'Scorpions'}
---
- - [2, 'Scorpions', 1965]
...

Версия:

Создаем свою первую базу данных на Tarantool

Prerequisites

Creating an application

Working with the database

Starting an instance

Creating a space

Creating indexes

Writing and selecting data