fbx/README.md

# Redis Module for maintaining hash by simple SQL

This module aims to provide simple DML to manipulate the hashes in REDIS for SQL users. It works as simple as you expected. It translates the input statement to a set of pure REDIS commands. It does not need nor generate any intermediate stuffs which occupied your storages. The target data is your hashes only.

## Usage
```bash
$ redis-cli
127.0.0.1:6379> hmset phonebook:0001 name "Peter Nelson"     tel "1-456-1246-3421" birth "2019-10-01" pos 3 gender "M"
127.0.0.1:6379> hmset phonebook:0002 name "Betty Joan"       tel "1-444-9999-1112" birth "2019-12-01" pos 1 gender "F"
127.0.0.1:6379> hmset phonebook:0003 name "Bloody Mary"      tel "1-666-1234-9812" birth "2018-01-31" pos 2 gender "F"
127.0.0.1:6379> hmset phonebook:0004 name "Mattias Swensson" tel "1-888-3333-1412" birth "2017-06-30" pos 4 gender "M"
127.0.0.1:6379> dbx.select name,tel from phonebook where gender = "F" order by pos desc
1) 1) name
   2) "Bloody Mary"
   3) tel
   4) "1-666-1234-9812"
2) 1) name
   2) "Betty Joan"
   3) tel
   4) "1-444-9999-1112"
```

## Getting started

### Get the package and build the binary:
```bash
$ git clone https://github.com/cscan/dbx.git
$ cd dbx/src && make
```

This plugin library is written in pure C. A file dbx.so is built after successfully compiled.

### Load the module in redis (3 ways)

1. Load the module in CLI
```bash
127.0.0.1:6379> module load /path/to/dbx.so
```

2. Start the server with loadmodule argument
```bash
$ redis-server --loadmodule /path/to/dbx.so
```

3. Adding the following line in the file redis.conf and then restart the server
```bash
loadmodule /path/to/dbx.so
```

If you still have problem in loading the module, please visit: https://redis.io/topics/modules-intro

## More Example

#### Select Statement
You may specify multiple fields separated by comma
```bash
127.0.0.1:6379> dbx.select name, gender, birth from phonebook
1) 1) name
   2) "Betty Joan"
   3) gender
   4) "F"
   5) birth
   6) "2019-12-01"
2) 1) name
   2) "Mattias Swensson"
   3) gender
   4) "M"
   5) birth
   6) "2017-06-30"
3) 1) name
   2) "Peter Nelson"
   3) gender
   4) "M"
   5) birth
   6) "2019-10-01"
4) 1) name
   2) "Bloody Mary"
   3) gender
   4) "F"
   5) birth
   6) "2018-01-31"
```

"*" is support
```bash
127.0.0.1:6379> dbx.select * from phonebook where birth > '2019-11-11'
1)  1) "name"
    2) "Betty Joan"
    3) "tel"
    4) "1-444-9999-1112"
    5) "birth"
    6) "2019-12-01"
    7) "pos"
    8) "1"
    9) "gender"
   10) "F"
```

If you want to show the exact keys, you may try rowid()
```bash
127.0.0.1:6379> dbx.select rowid() from phonebook
1) 1) rowid()
   2) "phonebook:1588299191-764848276"
2) 1) rowid()
   2) "phonebook:1588299202-1052597574"
3) 1) rowid()
   2) "phonebook:1588298418-551514504"
4) 1) rowid()
   2) "phonebook:1588299196-2115347437"
```

The above is nearly like REDIS keys command
```bash
127.0.0.1:6379> keys phonebook*
1) "phonebook:1588298418-551514504"
2) "phonebook:1588299196-2115347437"
3) "phonebook:1588299202-1052597574"
4) "phonebook:1588299191-764848276"
```

Each record is exactly a hash, you could use raw REDIS commands ``hget, hmget or hgetall`` to retrieve the same content

#### Where in Select Statement
This module supports =, >, <, >=, <=, <>, != and like conditions. Only single condition is allowed.
```bash
127.0.0.1:6379> dbx.select tel from phonebook where name like Son
1) 1) tel
   2) "1-888-3333-1412"
2) 1) tel
   2) "1-456-1246-3421"
```

#### Order in Select Statement
Ordering can be ascending or descending. All sortings are alpha-sort.
```bash
127.0.0.1:6379> dbx.select * from phonebook order by pos asc
...
127.0.0.1:6379> dbx.select * from phonebook order by pos desc
...
```

#### Delete Statement
You may also use Insert and Delete statement to operate the hash
```bash
127.0.0.1:6379> dbx.delete from phonebook where gender = F
(integer) 2
127.0.0.1:6379> dbx.delete from phonebook
(integer) 2
```

#### Insert Statement
```bash
127.0.0.1:6379> dbx.insert into phonebook (name,tel,birth,pos,gender) values ('Peter Nelson'     ,1-456-1246-3421, 2019-10-01, 3, M)
"phonebook:1588298418-551514504"
127.0.0.1:6379> dbx.insert into phonebook (name,tel,birth,pos,gender) values ('Betty Joan'       ,1-444-9999-1112, 2019-12-01, 1, F)
"phonebook:1588299191-764848276"
127.0.0.1:6379> dbx.insert into phonebook (name,tel,birth,pos,gender) values ('Bloody Mary'      ,1-666-1234-9812, 2018-01-31, 2, F)
"phonebook:1588299196-2115347437"
127.0.0.1:6379> dbx.insert into phonebook (name,tel,birth,pos,gender) values ('Mattias Swensson' ,1-888-3333-1412, 2017-06-30, 4, M)
"phonebook:1588299202-1052597574"
```
Please be noted that Redis requires at least one space after the single and double quoted arguments.
Or you may quote the whole SQL statement as below:
```bash
127.0.0.1:6379> dbx.insert "into phonebook (name,tel,birth,pos,gender) values ('Peter Nelson','1-456-1246-3421','2019-10-01',3, 'M')"
```

#### Issue command from BASH shell
```bash
$ redis-cli dbx.select "*" from phonebook where gender = M order by pos desc
1)  1) "name"
    2) "Mattias Swensson"
    3) "tel"
    4) "1-888-3333-1412"
    5) "birth"
    6) "2017-06-30"
    7) "pos"
    8) "4"
    9) "gender"
   10) "M"
2)  1) "name"
    2) "Peter Nelson"
    3) "tel"
    4) "1-456-1246-3421"
    5) "birth"
    6) "2019-10-01"
    7) "pos"
    8) "3"
    9) "gender"
   10) "M"
$ redis-cli dbx.select name from phonebook where tel like 9812
1) 1) name
   2) "Bloody Mary"
```
Note that "*" requires double quoted otherwise it will pass all the filename in current directory. Of course you could quote the whole SQL statement.
```bash
$ redis-cli dbx.select "* from phonebook where gender = M order by pos desc"
```

## Compatibility
REDIS v4.0

## License
MIT

## Status
Now the Select statement only supports single where condition and single order sequence. I will add more useful features in the future. Simple Insert, Update and Delete statement will be included finally. This project is in an early stage of development. Any contribution is welcome :D