Is Real a Valid Data Type in SQL?

Is Real a Valid Data Type in SQL?

In SQL, the REAL data type is used to store floating-point numbers with single precision. It represents a real number that can have decimal points. The REAL data type is also known as FLOAT, FLOAT4, or SINGLE.

The Syntax of REAL Data Type

The syntax for creating a column with the REAL data type in SQL is as follows:

CREATE TABLE table_name
(
    column_name REAL
);

Examples of REAL Data Type Usage

Let’s consider some examples to understand how the REAL data type works:

• Example 1:

  CREATE TABLE Products
  (
      ProductID INT,
      ProductName VARCHAR(50),
      Price REAL
  );
  

In this example, we create a table named “Products” with three columns: “ProductID”, “ProductName”, and “Price”. The “Price” column is of the REAL data type, which means it can store decimal values representing product prices.

• Example 2:

  INSERT INTO Products (ProductID, ProductName, Price)
  VALUES (1, 'Keyboard', 29.99);
  
  INSERT INTO Products (ProductID, ProductName, Price)
  VALUES (2, 'Mouse', 14.99);
  
  INSERT INTO Products (ProductID, ProductName, Price)
  VALUES (3, 'Monitor', 199.99);
  

In this example, we insert three records into the “Products” table.

Each record contains a “ProductID”, “ProductName”, and “Price”. The REAL data type allows us to store decimal values for the product prices.

Limitations of REAL Data Type

While the REAL data type is useful for storing floating-point numbers with single precision, it does have some limitations:

• Precision:

The REAL data type can store up to 7 digits of precision. This means that if you need to store numbers with more significant figures or higher precision, you should consider using the DOUBLE PRECISION or FLOAT8 data types instead.

• Rounding Errors:

Due to its limited precision, the REAL data type may introduce rounding errors when performing calculations.

It’s important to be aware of this and handle any potential discrepancies accordingly.

• Data Range:

The range of values that can be stored in a REAL column is dependent on the specific database system being used. It’s essential to consult the documentation of your chosen database system to understand the exact range and limitations.

In conclusion, yes, the REAL data type is valid in SQL and allows you to store floating-point numbers with single precision. However, it’s crucial to be aware of its limitations and consider alternative data types if higher precision or a larger range is required for your specific use case.