Greatest SQL

Project Description

A java based ORM for simplifying connecting to and from an SQL database without the need for SQL or connection management.

Technologies Used

• PostgreSQL - version 42.2.12
• Java - version 8.0
• Apache commons - version 2.1

Features

List of features ready and TODOs for future development

• Easy to use and straightforward user API.
• No need for SQL, HQL, or any databse specific language.
• Straightforward and simple Annotation based for ease of use.

To-do list:

• Mapping of join columns inside of entities.
• Implement of aggregate functions.
• Allow ORM to build table based on Annotations in Entities.

Getting Started

Currently project must be included as local dependency. to do so:

  git clone https://github.com/210119-java-enterprise/GreatestSQL_p1.git
  cd GreatestSQL_p1
  mvn install

Next, place the following inside your project pom.xml file:

  <dependency>
    <groupId>com.revature</groupId>
    <artifactId>greatestSQL_p1</artifactId>
    <version>1.0-SNAPSHOT</version>
  </dependency>

Finally, inside your project structure you need a application.proprties file. (typically located src/main/resources/)

 url=path/to/database
 admin-usr=username/of/database
 admin-pw=password/of/database  

Usage

Annotating classes

All classes which represent objects in database must be annotated.

• @Table(name = "table_name)

  • Indicates that this class is associated with table 'table_name'

• @Column(name = "column_name)

  • Indicates that the Annotated field is a column in the table with the name 'column_name'

• @Setter(name = "column_name")

  • Indicates that the anotated method is a setter for 'column_name'.

• @Getter(name = "column_name")

  • Indicates that the anotated method is a getter for 'column_name'.

• @PrimaryKey(name = "column_name")

  • Indicates that the annotated field is the primary key for the table.

• @SerialKey(name = "column_name")

  • Indicates that the annotated field is a serial key.

User API

• public static GSQL getInstance()

  • returns the singleton instance of the class. It is the starting point to calling any of the below methods.

• public HashMap<Class<?>, HashSet> getCache()

  • returns the cache as a HashMap.

  public boolean addClass(final Class<?> clazz)

  • Adds a class to the ORM. This is the method to use to declare a Class is an object inside of the database.

  public boolean UpdateObjectInDB(final Object obj,final String update_columns)

  • Updates the given object in the databse. Update columns is a comma seperated lsit fo all columns in the onject which need to be updated

  public boolean removeObjectFromDB(final Object obj)

  • Removes the given object from the database.

  public boolean addObjectToDB(final Object obj)

  • Adds the given object to the database.

  public Optional<List> getListObjectFromDB(final Class <?> clazz, final String columns, final String conditions)

  public Optional<List> getListObjectFromDB(final Class <?> clazz, final String columns, final String conditions,final String operators)

  public Optional<List> getListObjectFromDB(final Class<?> clazz)

  • Gets a list of all objects in the database which match the included search criteria
    • columns - comma seperated list of columns to search by.
    • conditions - coma seperated list the values the columns should match to.
    • operators - comma seperated list of operators to apply to columns (AND/OR) in order that they should be applied.

  public void beginCommit()

  • begin databse commit.

  public void Rollback()

  • Rollback to previous commit.

  public void Rollback(final String name)

  • Rollback to previous commit with given name.

  public void setSavepoint(final String name)

  • Set a savepoint with the given name.

  public void ReleaseSavepoint(final String name)

  • Release the savepoint with the given name.

  public void enableAutoCommit()

  • Enable auto commits on the database.

  public void setTransaction()

  • Start a transaction block.

  public void addAllFromDBToCache(final Class<?> clazz)

  • Adds all objects currently in the databse of the given clas type to the cache.

  License

  This project uses the following license: GNU Public License 3.0.