Naming Tables and Other Database Objects
General Naming Principles
- Clarity and Descriptiveness: Names should clearly describe the purpose or contents of the object. Avoid ambiguous or overly abbreviated names.
- Consistency: Use a consistent naming convention throughout the database. This helps in understanding and managing the database schema.
- Avoid Reserved Words: Do not use SQL reserved keywords or special characters in names. If unavoidable, use quotation marks or escape characters according to the DBMS rules.
- Case Sensitivity: Be aware of the case sensitivity rules of the DBMS you are using. For example, MySQL on Windows is case-insensitive by default, while PostgreSQL is case-sensitive.
Naming Conventions for Tables
- Singular vs. Plural: Choose a convention (singular or plural) and stick with it. Commonly, singular names are used, e.g., Customer instead of Customers.
- Descriptive Names: Use names that describe the entity or data stored in the table. For example, Employee is preferable to Emp or EmpTable.
- Avoid Prefixes: Avoid unnecessary prefixes like tbl_, e.g., use Customer instead of tbl_Customer.
Examples:
- Customer
- Order
- Product
Naming Conventions for Columns
- Descriptive Names: Column names should clearly indicate the type of data they store, e.g., FirstName, DateOfBirth.
- Consistency: Use a consistent naming pattern for columns across tables. For example, if you use ID for primary keys in one table, use it consistently in other tables.
- Avoid Abbreviations: Avoid unclear abbreviations. For instance, FirstName is better than FName.
Examples:
- CustomerID
- OrderDate
- ProductPrice
Naming Conventions for Indexes
- Include Table and Column Names: Index names should include the table and column names to indicate their purpose. This is especially useful in identifying indexes quickly.
- Use Descriptive Names: Include the type of index, e.g., IX_Customer_LastName for an index on the LastName column of the Customer table.
Examples:
- IX_Customer_LastName
- PK_Order_OrderID (for a primary key index on OrderID)
Naming Conventions for Views
- Descriptive Names: Views should be named based on the data they present or the purpose they serve. For example, CustomerOrderSummary for a view summarizing customer orders.
- Include Purpose: Incorporate the purpose of the view in its name to make it clear, e.g., vw_CustomerDetails.
Examples:
- vw_CustomerOrders
- CustomerOrderSummary
Naming Conventions for Stored Procedures
- Action-Oriented Names: Use names that describe the action the procedure performs. Prefixes such as sp_ are often used to denote stored procedures.
- Include Purpose: For instance, sp_GetCustomerDetails clearly indicates a procedure that retrieves customer details.
Examples:
- sp_InsertCustomer
- sp_UpdateOrderStatus
Naming Conventions for Functions
- Descriptive Names: Functions should be named based on their functionality, e.g., CalculateDiscount.
- Include Purpose: Use clear names that indicate what the function calculates or returns, e.g., fn_GetEmployeeAge.
Examples:
- fn_CalculateTax
- fn_GetProductName
Naming Conventions for Constraints
- Descriptive Names: Name constraints based on the table and column they apply to. This makes it easier to understand their purpose.
- Include Type: Include the type of constraint in the name, e.g., CHK_Product_Price for a check constraint on the Price column of the Product table.
Examples:
- PK_Customer_CustomerID (for a primary key constraint)
- FK_Order_CustomerID (for a foreign key constraint)
- CHK_Product_Price (for a check constraint)
Naming Conventions for Sequences
- Descriptive Names: Sequences should be named in a way that indicates their purpose, typically involving the table they are associated with.
- Include Type: Include the object type, e.g., seq_CustomerID for a sequence generating customer IDs.
Examples:
- seq_OrderID
- seq_ProductID
Naming Conventions for Triggers
- Action-Oriented Names: Triggers should be named to reflect the action they are associated with (e.g., BeforeInsert).
- Include Table Name: Include the table and the type of trigger action in the name, e.g., trg_BeforeInsert_Employee.
Examples:
- trg_AfterUpdate_Customer
- trg_BeforeDelete_Order
Conclusion
Adhering to consistent and descriptive naming conventions for tables and other database objects is crucial for maintaining clarity and manageability in a database schema. Well-chosen names facilitate easier navigation, debugging, and collaboration, and help ensure that the database structure is logical and intuitive.