SQL Naming Conventions
A naming convention is a set of unwritten rules that you should use if you want to increase the readability of the whole data model:
- All SQL commands should be written in uppercase letters.
- Use lower letters when naming database objects.
- Use the singular for the table or column name such as
employee. - If the name includes more than one word, use underscore to connect them like
first_name. - It would be the best to simply name a primary key column “id.”
- Foreign key columns store values from the range of primary key of the referenced table, and you should use that table name and “id,” e.g.,
customer_id. - The name or variable uses the italic font style or
symbolfont if it is used in text.
SQL is not case sensitive.
Semicolon after SQL Statements?
Some database systems require a semicolon at the end of each SQL statement. Semicolon is the standard way to separate each SQL statement in database systems that allow more than one SQL statement to be executed in the same call to the server. The following demonstration may use MySQL database, which does not require to put a semicolon after each SQL statement, but some databases force you to use it.
Demonstration
Below is an SQL test area from W3Schools, which uses the well-known Northwind sample database. The tables here are for read only because of the problem of embedding the scripts. For a fully working example, check this by using Chrome.
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Result:
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The Database includes:
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The Database includes:
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