Author: Ian

What is SQL?

Posted on by Ian

SQL is the standard language for querying data inside a relational database management system (RDBMS). It is supported by all of the major database systems, such as Microsoft Access, SQL Server, MySQL, Oracle, PostgreSQL, DB2, etc.

SQL is a relatively easy language to learn when compared to most programming languages. It is based on SQL “statements” that, at times, can resemble natural language.

For example:

SELECT CustomerName
FROM Customers
WHERE CustomerId = 1

The above SQL statement is asking the database to:

“Select the value of the CustomerName column from the Customers table where the CustomerId column’s value equals 1“.

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How to Create a Relationship in MySQL Workbench

Posted on by Ian

To create a relationship in MySQL Workbench:

  1. Create a database model (either create a new model or reverse engineer an existing database)
  2. Viewing the database model, double click on the first table of the relationship
  3. The bottom pane will open with the table details. Click on the Foreign Keys tab
  4. In the left pane, select the foreign key field and referenced table
  5. In the middle pane, select the foreign column and referenced (primary key) column
  6. In the right pane, set any Update/Delete actions you’d like to occur when a primary key record is updated or deleted

The relationship is now established. Repeat steps 4 to 6 for any other foreign key columns in that table.

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How to Reverse Engineer a Database in MySQL Workbench

Posted on by Ian

To reverse engineer a database in MySQL Workbench:

  1. Select Database > Reverse Engineer from the top menu of MySQL Workbench
  2. Set/review parameters for connecting to the DBMS then click Continue
  3. Enter password if required, then click OK
  4. The wizard will connect to the DBMS, fetch a list of databases, and check for any issues. Click Continue
  5. Select the database/s you would like to reverse engineer, then click Continue
  6. The wizard will retrieve all objects from the selected schema/s and check the results. Click Continue
  7. Select the database objects you’d like to have reverse engineered, then click Execute
  8. The wizard will now reverse engineer all selected objects and generate the EER diagram (behind the scenes). Click Continue
  9. A summary is displayed. Click Close

The EER diagram is now displayed on the screen.

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How to Create a Database from a Script in MySQL

Posted on by Ian

To create a database from a script in MySQL:

  1. Open a Query tab in MySQL Workbench
  2. Run a CREATE DATABASE or CREATE SCHEMA statement to create the database (example below)

This will create a new database.

Screenshot of SQL script that creates a database in MySQL
Example of an SQL script that creates a database with tables, columns etc. In this case, the script has just run and has created the “Music” database. You can see the tables and their columns open in the left navigation pane.

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How to Generate a Script from a Diagram in MySQL Workbench

Posted on by Ian

To generate a script from a diagram in MySQL Workbench:

  1. Select File > Export > Forward Engineer SQL CREATE Script...
  2. Enter a location to save the file (optional) and set options to include on the script (such as DROP statements etc), then click Continue
  3. Exclude any objects by deselecting them, otherwise leave them as is, then click Continue
  4. The script is generated. You can copy it to your clipboard or click Finish to save it to a file

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How to Create a New Database Diagram using MySQL Workbench

Posted on by Ian

To create a new database diagram using MySQL Workbench:

  1. Click File > New Model from the menu
  2. Create a new schema by clicking the + icon next to Physical Schemas
  3. Add tables by clicking Add Tables, then add/configure their columns in the bottom pane.
  4. Create relationships and any other configurations by using the various tabs
  5. Create a diagram by clicking Model > Create Diagram from Catalog Objects

The diagram will be created. You can rearrange the tables to a more suitable layout by clicking and dragging.

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