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Toad Data Modeler 7.0 - User Guide

Introduction User Interface Models and Model Objects
Physical Data Model
Entity Relationship Diagram Objects Basic Database Design Advanced Database Design
Universal Data Model Logical Data Model Working with Model Objects
Features and Tools
Application Variables Export/Import DDL Script Generation Graphics Model Actions Print Create New Project Reports Reverse Engineering Scripting and Customization About Templates Tips and Tricks Toad for Oracle Integration Toad Intelligence Central (TIC) Integration Tools Version Control
Options and Configuration Databases
Amazon Redshift 1.0 IBM DB2 LUW 9.5 IBM DB2 LUW 9.7 IBM DB2 LUW 10.1 IBM DB2 LUW 10.5 IBM DB2 LUW 11.1 IBM DB2 z/OS 10 IBM DB2 z/OS 11 Greenplum 4.1 Greenplum 4.2 Ingres 9.3 Ingres 10.0 EDB Postgres Advanced Server 10 Microsoft Access 2007/2010 Microsoft Azure SQL Database V12 Microsoft SQL Server 2005 Microsoft SQL Server 2008 Microsoft SQL Server 2012 Microsoft SQL Server 2014 Microsoft SQL Server 2016 Microsoft SQL Server 2017 MySQL 5.0 MySQL 5.1 MySQL 5.5 MySQL 5.6 MySQL 5.7 MySQL 8.0 Oracle 10g Oracle 11g Release 1 Oracle 11g Release 2 Oracle 12c Release 1 Oracle 12c Release 2 Oracle 18c Specifics - Oracle 12c Release 2 PostgreSQL 9.0 PostgreSQL 9.1 PostgreSQL 9.2 PostgreSQL 9.3 PostgreSQL 9.4 PostgreSQL 9.5 PostgreSQL 10 SQLite 3.7 Sybase ASE 15.5 Sybase ASE 15.7 SAP ASE 16.0 Sybase IQ 15.2 Sybase SQL Anywhere 11 SAP SQL Anywhere 17 Teradata 13 Vertica Database 8.0
Copyright Legal Notices

Mandatory/Optional Parent/Child

To set Parent/Child entity as Mandatory/Optional

  1. Double-click a relationship on workspace to open Relationship Properties.
  2. Switch to the General tab and check/uncheck Mandatory Parent/Child checkbox in the Cardinality section.

Parent: Mandatory

Child: Mandatory

A teacher MUST teach a lecture (the record related to lecture is mandatory), a lecture MUST be taught by a teacher (the record related to teacher is also mandatory. Teacher is Mandatory.)

Parent: Mandatory

Child: Optional

A teacher MAY teach a lecture (the record related to lecture is Optional), a lecture MUST be taught by a teacher (Teacher is Mandatory.)

Parent: Optional

Child: Mandatory

A teacher MUST teach a lecture (lecture is Mandatory), a lecture MAY be taught by a teacher (teacher is Optional).

Parent: Optional

Child: Optional

A teacher MAY teach a lecture (lecture is Optional), a lecture MAY be taught by a teacher (teacher is Optional).

The information can be found on Relationship Properties form, see graphical representation at bottom of the form.

Set up Referential Integrity Rules

To set up referential integrity rules for Parent entities

Open the Relationship Properties form and see the Referential Integrity group box.

Here, you can change the None rule to:

  • Restrict
  • Cascade
  • Set Null
  • Set Default

The default rule can be re-configured.

Note: Some databases do not support Referential Integrity (RI) rules.

Connect Parent and Child Entities

Toad Data Modeler allows you to connect Parent and Child entities through the following unique values:

  • Key (Primary or Alternate Key) of parent entity
  • Unique Index of parent entity

To change the linking method

  1. Open the Relationship Properties form and see the Relationship Type group box.
  2. From the Parent Key box, select the method. If neither Unique item, nor Alternate Key exists, only the Primary key is available.

Note: Some databases do not support Alternate Keys.

Understanding Foreign Keys

There are two types of foreign keys in Toad Data Modeler:

  • Primary Foreign keys (PFK, graphically marked by blue key).
  • Foreign keys (FK, graphically marked by green key).

PFK

As soon as you create an identifying relationship, Toad Data Modeler automatically adds a copy of the primary key of the Parent table to the Child table - Primary Foreign Key (PFK). (The foreign key in Child table is a part of the primary key.)

FK

As soon as you create a non-identifying relationship, Toad Data Modeler automatically adds a copy of the primary key of the Parent table to the Child table - Foreign key (FK). (This foreign key in Child table is not a part of the primary key.)

In other words, foreign keys (PFKs and FKs) are imported from parent entities to child entities automatically when you create relationship. Foreign keys cannot exist without relationships. Therefore, you are not allowed to delete FK or PFK from Child tables either. To delete them, you have to delete appropriate relationship.

In Toad Data Modeler, information on foreign keys can be found in:

  • The Attribute Properties dialog | Foreign Keys tab where you can see details on particular FK.
  • The Relationship Properties dialog where you set linking method between parent and child entities.

Foreign Keys Mapping

In Toad Data Modeler, you can control your foreign keys. Foreign keys mapping feature allows you to create Compound Keys, use existing keys etc.

Example:

You have reverse engineered a model without relationships. In Toad Data Modeler, a new model has been created. However, information about foreign keys has been lost as in Toad Data Modeler stands that foreign keys cannot exist without relationships. Now you need to create relationships in Toad Data Modeler.

As soon as you create a new relationship, a new foreign key is added to the child entity automatically or existing attribute is mapped to primary key automatically.

In case you need to choose different column for the relationship, edit the relationship and choose the new column on tab General.

Automatic FK Mapping

You can also set Automatic FK Mapping in Settings | Options | Physical Model.

  • Disable—FK mapping is OFF
  • Enable—Toad Data Modeler searches for matching attributes. If a single option is found, it gets mapped. If multiple options are found, a dialog appears.
  • Always Show Dialog—The dialog opens even if only a single option is found.

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