An SQL-like interface for AntidoteDB.
AQL can be used through Docker (recommended), or directly through rebar3.
To use AQL through Docker simply pull the image from Docker Hub here. If docker can't pull the lastest version of the image, do it manually by:
docker pull jpdsousa/aql_antidote:<latest-version-available>
This image starts an antidoteDB server (uses this image) on background and runs an AQL instance of top.
This is the recommended way of running AQL, at least for single-client use.
This project can also be installed "manually" through rebar3. In order to do so, clone this repository:
$ git clone https://github.com/JPDSousa/AQL
Open a terminal in the project folder (cd AQL
) and then compile the project:
$ make compile
Now, to run the client, you must have one (or more) running instances of AntidoteDB. To start in shell mode run the following command:
$ make shell
You can also start in development mode with:
$ make dev
AQL is an SQL-variant, designed to work with AntidoteDB API.
AQL provides a shell mode, which is the easiest way to use the client. In shell mode, you'll see a prompt like this:
AQL>
Use the prompt to input AQL statements.
The AQL API is pretty straightforward. There is a main module called
aqlparser
with a method parse
, which takes a tuple as well as the AntidoteDB node long name. The two options
available are:
{str, AQLCommand}
Which parses the AQLCommand
and outputs the result.
{file, AQLFile}
Which takes a path to a file (no specific format) and parses its content as an AQL command.
For instance, to show all existing tables in the database through the API, use:
aqlparser:parse({str, "SHOW TABLES"}, '[email protected]').
AQL supports multiple SQL-like operations such as:
- Data definition
- CREATE TABLE
- Data manipulation
- SELECT
- INSERT
- UPDATE
- DELETE
- Admin
- SHOW TABLES/INDEX
AQL supports a limited set of types:
- VARCHAR - common text data type (similar to SQL's VARCHAR)
- INTEGER/INT - common integer data type (similar to SQL's INTEGER)
- BOOLEAN - common boolean
- COUNTER_INT - integer counter, with bounds (based on AntidoteDB's Bounded Counter)
Creates a new table. If the table already exists the new table will overwrite it (any concurrent conflicts will be resolved with a Last Writer Wins CRP).
CREATE @AW TABLE Student (
id INT PRIMARY KEY,
Name VARCHAR,
Age INT DEFAULT 18,
YearsLeft COUNTER_INT CHECK GREATER 0,
Passport_id INTEGER FOREIGN KEY @FR REFERENCES Passport(id)
);
The primary key constraint must be specified after the column which is to be set as the primary key (multiple columns as primary keys are not supported). Any datatype can be a primary key.
Primary keys only guarantee uniqueness. Although, if two rows with the same primary key are inserted (either concurrently or not), both insertions will be merged, and all columns columns will also be merged according to its datatypes.
AQL also supports constraints on counters (counter_int
). Assign numeric bounds
to any COUNTER_INT
column by:
CHECK [ GREATER | GEQ | SMALLER | SEQ] value
Where value
is the respective bound.
You can also define a default value for a record (not allowed in primary keys). Default values are used when no value is specified for a record.
Syntax:
column_x data_type DEFAULT value
Where value
is the default value.
Foreign keys allow users to create custom relations between elements of different
tables. To create a foreign key relation simply add to the column that will be
the foreign key: FOREIGN KEY [ @FR | @IR ] REFERENCES _parentTable_(_parentColumn_)
,
where _parentTable_
is the parent table name (e.g. Passport
) and _parentColumn_
is
the parent column name (e.g. id
). All foreign keys must point to columns with a
unique constraint, which is only guaranteed in primary keys.
Force-revive (@FR
) and Ignore-revive (@IR
) are conflict resolution policies used
to resolve any referential integrity related conflicts generated by concurrent operations.
Force-revive will revive all records (deleted) involved in the conflict, while
Ignore-Revive deletes all involved records in case of conflict.
SELECT is the main read operation in AQL (similar to SQL). The operation issues a read operation in the database engine (AntidoteDB).
SELECT * FROM Persons WHERE PersonID = 20;
Note: This operation only supports reads per primary key (such as the one in the example). This is a temporary limitation.
Inserts new records in a table. If a value with the primary key already exists it will be overwritten.
INSERT INTO (PersonID, LastName, FirstName, Address, City) VALUES (10, 'Last1', 'First1', 'Local1', 'City1')
The table columns must always be specified.
Updates an already-existent row on the specified table.
UPDATE Persons
SET FirstName ASSIGN 'First2'
WHERE PersonID = 1
Updates all rows in table Persons
where PersonID
has value 1. The update
sets column FirstName
to value 'First2'
. The operation keyword (e.g.
ASSIGN
) depends on the AQL datatype:
- VARCHAR
ASSIGN
- sets the column(s) of typeVARCHAR
to the value specified.
- INTEGER
ASSIGN
- sets the column(s) of typeINTEGER
orINT
to the value specified.INCREMENT
- increments the column(s) of typeINTEGER
by the value specified.DECREMENT
- decrements the column(s) of typeINTEGER
by the value specified.
- COUNTER_INT
INCREMENT
- increments the column(s) of typeCOUNTER_INT
by the value specified.DECREMENT
- decrements the column(s) of typeCOUNTER_INT
by the value specified.
- BOOLEAN
ENABLE
- sets the boolean value totrue
DISABLE
- sets the boolean value tofalse
Just like in a SELECT operation, the where clause can only filter primary keys.
Deletes a set of records from the specified table.
DELETE FROM Persons Where PersonID = 2004525
Just like in a SELECT operation, the where clause can only filter primary keys.
If the WHERE
clause is absent, all the records in the table are deleted.