What Are Oracle Data Types?

Oracle Database is used by companies to store and manage the organizational information within the database in SQL. During creation of a table in Oracle Database, all columns are required to have specific types of data.The data type is used to tell Oracle how the data stored in the database column should look like text, numeric data, date, file, or other types of large content.

For example, in an employee table, the name of the employee is captured as text data type, the salary is captured as numeric data type, and joining date is captured as date data type. Likewise, in a product table, the names of the products could be captured as text data type and prices captured as numeric data type, and so forth. Therefore, one needs to understand Oracle data types in order to learn SQL, database management, and Oracle programming.

For both students and professionals, the study of this topic will form a very solid foundation for dealing with actual databases. The students at Srijan Institute learn about the workings of Oracle through actual examples and usage scenarios. An organized oracle online course will also help the learners to know about what tables and SQL in the oracle.

What are Oracle Data Types?

There are different data types in oracle which tell the type of data to be stored in any table field, any variable or expression. It provides information to oracle, in how it will deal with data while within SQL database tables.

Example : a company creates an employee table the EmployeeID can be stored as a number, the employee name as a text type and the joining date can be a date type data type. In this case every field will have its own meaning and so requires the corresponding data type.

Oracle data types also help in ensuring data accuracy. A numeric field makes it possible for arithmetic to be performed on the data. A date field allows for comparisons based on dates and filtering. Selecting the correct Oracle data type is not just about data storage. It also influences factors like storage space utilization, query speed, and database design quality in general.

Categories of Oracle Data Types

Oracle provides different data types for different kinds of information. Each category has its own role in database design. The main categories include character, numeric, date and time, large object, RAW, and ROWID data types.

Character Data Types

Character data types are used to store text values in the database. These can include employee names, email addresses, city names, product titles, department names, or short codes.

Numeric Data Types

Numeric data types are used to store numeric values in the database table. Number datatype is widely used by Oracle to store numeric values in database tables. It is used to store employee id, salary, cost of product, marks, quantity, percentage, etc in the SQL database table.

Example- Salary can store NUMBER(10,2) which represents 10 total digits and 2 digits after decimal.

Date and Time Data Types

Date and time data types are used when a column needs to store dates, time, or timestamp values. These are useful for joining dates, invoice dates, order dates, payment dates, login records, and transaction history.

Common data types in this category include DATE, TIMESTAMP, TIMESTAMP WITH TIME ZONE, and INTERVAL.

Large Object Data Types

Large object datatypes are employed where regular datatypes like texts and numbers cannot suffice. They allow storing of large text files, images, documents, video files, and scanned documents.

Some examples of large object datatypes include CLOB, BLOB, NCLOB, and BFILE. CLOB is used to store text data, while BLOB is used to store binary files in the SQL database table.

RAW and ROWID Data Types

RAW is used to store binary data in raw format. ROWID stores the unique address of a row in a database table. These data types are mostly used in technical or advanced database operations.

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Commonly Used Oracle Data Types with Examples

There are different data types provided by Oracle. But there are some data types which are often used in day-to-day operations. The following are some of the most common data types when creating tables such as Employee, Customer, Product, Orders, Payment, and Accounting tables are:

• VARCHAR2: VARCHAR2 is used to store variable-length text. It is suitable for values where the length may change from one record to another record in the database.

• CHAR : CHAR is used to store fixed-length text. It helps in cases where the length of the value is fixed. This is used to store values such as A to indicate active or I to indicate inactive. In cases of general text fields, VARCHAR2 is used.

• NUMBER : NUMBER is used to store numeric values. It can store both whole numbers as well as decimal values. It is useful for prices, salary, quantity, marks, IDs, and percentage values.

• DATE : DATE is used to store the values of date and time. It will store the date and time at which an order was made. It is frequently used to add details in the database like joining dates, invoice date, payment date, delivery date, and birth date.

• TIMESTAMP : TIMESTAMP stores date and time with more precision than DATE into the database table. This is helpful when exact time tracking is required, such as user login records, transaction history, audit logs, and system updates.

• CLOB : CLOB stands for Character Large Object. It is used to store large text content. This can store long descriptions, articles, comments, terms and conditions, or detailed documents.

• BLOB : BLOB stands for Binary Large Object. It converts text data into binary data for storing the data into a database. With this it can store PDFs, images, scanned documents, certificates, videos, and other file based data into tables.

How do you pick the Right Oracle Data Type?

The choice is generally related to the value that you want to represent. For textual information such as emails addresses names and addresses generally VARCHAR2 are best. If it is a fixed set of characters, use CHAR.

For numbers such as salary, marks, price, quantity, or percentage, use NUMBER. For dates and time-based records, use DATE or TIMESTAMP. If the column stores long text, use CLOB. For images, PDFs, or files, use BLOB. Also, avoid giving unnecessary large sizes.

Best Practices for Using Oracle Data Types

Selection of Oracle datatype depends upon the value we are going to store in that field. When the values are text-oriented, VARCHAR2 should be used. If we have a fixed code to enter, then we may choose CHAR.

If the values include numbers like salary, marks, price, quantity, and percentages, then we may select NUMBER. If the column stores long text, use CLOB. For images, PDFs, or files, use BLOB. Also, avoid giving unnecessary large sizes. Date should always be stored in DATE or TIMESTAMP data type and never in text data type. CLOB/BLOB should be used when large files have to be stored.

It is very important to know about Oracle data types when creating a database because they determine how each value is going to be used. Selection of the right data type allows us to save our data in the form of numbers, text, date, timestamp, big text, or files. Oracle Data Types like VARCHAR2, CHAR, NUMBER, DATE, TIMESTAMP, CLOB, and BLOB are some data types which are widely used in databases.

The use of Oracle Data Types makes it very easy to manage the tables. Oracle data types play an essential role for those who wish to master the concepts of SQL programming. With proper training from Srijan Institute, one can develop an effective base for future professional opportunities connected with Oracle technologies.

FAQs Related to Oracle Data Types

Q1. What are Oracle data types?

A. The oracle data types identify whether data types should store data types into variables, expressions, and columns. It guides Oracle to recognize data like characters, files, date, large object data, number, timestamp, and so on.

Q2. What are the main kinds of Oracle data types?

A. The main kinds of the Oracle data types are; Character data type, RAW data type, Numeric data type, Large Object data type, ROWID data type, Date and Time data type.

Q3. Which Oracle data type should I use for storing numbers?

A. If you want to store numbers like EmployeeID, Salary, Price, marks, quantity, percentage and all calculated data, you should use NUMBERIC DATATYPE.

Q4. What’s the difference between VARCHAR2 and CHAR in Oracle?

A. When comparing Oracle data types, VARCHAR2 is used to store the variable length text and CHAR is used to store the fixed length text. Use VARCHAR2 for name, email, address and use CHAR for codes which you would like them fixed.

Q5. What is the reason behind picking the correct Oracle data type?

A. The right picking of oracle datatypes help the business improve the accuracy, minimize errors of all sorts and help in space-saving as well as in query performance and ultimately making your Oracle databases neat and robust.