Denis Database

Denis Database is a Java Library that works with Redis logic and has a simple structure. It provides ease of access and manipulation of temporary data by storing operations in the cache. It increases database categorization with action statuses, providing ease of development.

Quick Start

Requirements: Java 17 or newer.

Build locally:

mvn package

Run from the generated jar:

java -jar target/denis-0.0.2.9-alpha.jar --help
java -jar target/denis-0.0.2.9-alpha.jar server
java -jar target/denis-0.0.2.9-alpha.jar cli

Install From Release

Download denis-<version>-project-bundle.zip or denis-<version>-project-bundle.tar.gz from GitHub Releases, extract it, then run:

sh install.sh
denis --help
denis server
denis cli

Windows:

install.bat
denis.bat --help
denis.bat server
denis.bat cli

CLI Tools

The release bundle includes bin/denis and bin/denis.bat wrappers.

denis --version
denis server
denis cli
denis cli --help
denis cli token -l
denis cli token -c

Runtime files are kept next to the installed app by default: denis.properties, denis.toml, ddb.json, pawd.dat, and logs/.

SQL Queries

After logging in and authenticating to a project token, Denis accepts standard SQL-style queries over the TCP protocol. You can send them directly or prefix them with SQL.

Supported query subset:

• CREATE TABLE <table> (<column> <type>, ...)
• INSERT INTO <table> (<columns>) VALUES (<values>)
• SELECT <columns|*> FROM <table> [WHERE <column> = <value>]
• UPDATE <table> SET <column> = <value> [, ...] [WHERE <column> = <value>]
• DELETE FROM <table> [WHERE <column> = <value>]
• DROP TABLE <table>

Example:

CREATE TABLE users (id INT, name TEXT);
INSERT INTO users (id, name) VALUES (1, 'Ada');
SELECT * FROM users WHERE id = 1;
UPDATE users SET name = 'Grace' WHERE id = 1;
DELETE FROM users WHERE id = 1;
DROP TABLE users;

DAPI

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Detailed library information about DDB.

Actions

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actString Class

actString is a class designed to manage data with a String key and String value pair. This class is used for basic CRUD operations and checking data existence.

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Methods

Method	Return Type	Description
set(String key, String value)	Void	Saves or updates the specified key and value.
get(String key)	String	Returns the value corresponding to the given key. Returns null if no value exists.
del(String key)	Void	Deletes the specified key and its value.
exists(String key)	Boolean	Checks whether the given key exists.

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Usage Example

actString actstr = new actString();

// Adding data
actstr.set("key1", "value1");

// Retrieving data
String value = actstr.get("key1"); // "value1"

// Data check
boolean exists = actstr.exists("key1"); // true

// Deleting data
actstr.del("key1");

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actListrig Class

actListrig is a structure that associates a List<String> key with a String value. It is created using ConcurrentHashMap, which is suitable for parallel operations.

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Methods

Method	Return Type	Description
set(List<String> key, String value)	Void	Saves or updates the specified list key and value pair.
get(List<String> key)	String	Returns the value corresponding to the given list key. Returns "null" if no value exists.
del(List<String> key)	Void	Deletes the specified list key and its value.
exists(String key)	Boolean	Checks whether the given list key exists.
getStore()	ConcurrentHashMap	Returns all data.

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Usage Example

import java.util.Arrays;
import java.util.List;

actListrig actlist = new actListrig();

// Create key
List<String> key = Arrays.asList("item1", "item2");

// Add data
actlist.set(key, "value1");

// Retrieve data
String value = actlist.get(key); // "value1"

// Data check
boolean exists = actlist.getStore().containsKey(key); // true

// Delete data
actlist.del(key);

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Class Differences and Usage Scenarios

Feature	actString	actListrig
Key Type	String	List<String>
Data Management	Single key-value pair	Managing multiple keys together
Use Case	Managing simple structures	Managing complex, hierarchical structures

Example Scenarios:

• actString can be used to store username-password pairs in a database.
• actListrig can be used to associate product categories and subcategories on an e-commerce site.

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actStrist Class

actStrist is a class that associates a String key with a List<String> value. It uses the ConcurrentHashMap infrastructure suitable for parallel operations. This class is designed to bind multiple values to a single key.

Methods

Method	Return Type	Description
set(String key, List<String> value)	Void	Saves or updates the specified key and value list.
get(String key)	List<String>	Returns the value list corresponding to the given key. Returns ["null"] if no value exists.
del(String key)	Void	Deletes the specified key and its value list.
exists(String key)	Boolean	Checks whether the given key exists.
getStore()	ConcurrentHashMap	Returns all data.

Usage Example

actStrist actstrist = new actStrist();

// Create key and value list
String key = "group1";
List<String> values = Arrays.asList("item1", "item2", "item3");

// Add data
actstrist.set(key, values);

// Retrieve data
List<String> retrievedValues = actstrist.get(key);
System.out.println(retrievedValues); // [item1, item2, item3]

// Data check
boolean exists = actstrist.exists(key);
System.out.println(exists); // true

// Delete data
actstrist.del(key);

// Check again
exists = actstrist.exists(key);
System.out.println(exists); // false