ER/One : A free Data Modeler Tool                 Download

ER/One Data Modeler allows developers to graphically design databases by using physical models and entity relationship diagrams to automatically generate the most popular SQL databases. It also allows developers to easier deploy the databases by offering a sophisticated visual data modeling environment. The software reduces errors in databases development while improves productivity and simplifies data modeling. Developers can visualize physical models structures to understand their databases, create new databases, modify, analyze, and optimize the solution. It is extremely easy to use and understand. Dedicated for both beginners and experts in database modeling, it is simple to get familiar with. ER/One provides all the features you expect of a professional database modeling and design tool.

ER/One Data modeler also allows:

  • Generation of physical data models.
  • Managing an unlimited numbers of tables.
  • Creation of index, keys, triggers, stored procedures, views, generators and domains.
  • Generation of a script for oracle, MS SQLserver, PostgreSQL, MySQL, Interbase and Firebird database engines.


  • DBMS-specific data models
  • Large Model Management
  • Define entities, attributes, domains, indexes, sequences and relationships
  • Visual data modeling
  • Object browser (treeview)
  • Check Model
  • Generate DDL script
  • Options management
  • Triggers
  • Define views and procedures
  • Export model as an Image
  • Preview and print of model with printer setting
  • Duplicate an entity
  • Other interesting features remain to be integrated, after stabilizing the beta version:
    • Types of relationships: although these features exist in ER/One and are easily used (manually), many softwares do it automatically and so we plan to integrate them soon:
      • Identifying relationship
      • Many to many relationship
    • Undo-Redo
    • As well as several other features


Your feedback interests us  , we kindly ask you to send us :

  • The detected bugs
  • Features to improve
  • Problems found in different databases (Example : Data types,used domains…)

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0.8.6 | 28/12/2017

  • Fixed: Unable to generate the script after starting a new project in Oracle and Firebird
  • Fixed: Unable to create the script for domains in MS Sql Server
  • Fixed: Some issues with entity font
  • Fixed: Cannot load column size in old projects
  • Fixed: Unsaved option choices
  • Fixed: Some others issues
  • Add:  Connection for MySQL to generate the script directly

0.8.5 | 30/11/2017

  • Fixed: Duplicate an entity will duplicate the key fields in the primary key
  • Fixed: Unable to add tables after changing the project name
  • Fixed: Editing a column primary key, duplicate the edited column in the keys tab when there a
    multiple keys
  • Fixed: Empty Index fields, empty key fields if the fields are a foreign keys and the relationship
    deleted or the primary key deleted
  • Fixed: SQL Syntax styler
  • Fixed: the foreign keys undeleted from the tree-view after deleting the parent table
  • Fixed: ER/One crash when moving a relationship and using the right-click at the same time
  • Fixed: some others issues
  • Add:  Able to create the second relationship between two tables | 26.10.2017

  • Fixed: A duplicate columns in keys fields and indexes fields  when there are multiple keys or multiple indexes

0.8.4 | 23.10.2017

  • Fixed: Incorrect order when there are a multiple columns primary key in one table (in script)
  • Fixed: Changing the name and the constraint name in the relationship generate an error
  • Fixed: some others issues
  • Add: many to many relationship
  • Add: check a duplicate constraint name if exist

0.8.3 | 09.10.2017

  • Fixed : Display problem in the preview
  • Fixed : Unable to add a column to an empty table
  • Fixed : Unsaved position of project frame in diagram
  • Add : Reach an entity from treeview  (right mouse  click)
  • Add : Reach a relationship from treeview  (right mouse click)

0.8.2 | 26.09.2017

  • Fixed : Error generated by deactivating primary key
  • Fixed : Page number of A4 in diagram
  • Add : Stored procedures
  • Add : Views