What Is Real Data Type in PostgreSQL?

In PostgreSQL, the REAL data type is used to store single-precision floating-point numbers. It is a 4-byte data type that can represent a wide range of values, including both positive and negative numbers.

Working with REAL Data Type

To define a column with the REAL data type in PostgreSQL, you can use the following syntax:

CREATE TABLE table_name (
    column_name REAL
);

You can also specify the precision of the REAL data type using the syntax:

CREATE TABLE table_name (
    column_name REAL(precision)
);

The precision parameter specifies the maximum number of digits that can be stored in the column. The default precision is 6 if not specified.

Examples

Let’s take a look at some examples to understand how the REAL data type works:

• Create a table named “products” with a column “price” of type REAL:

    CREATE TABLE products (
        price REAL
    );
  

• Insert some sample data into the table:

    INSERT INTO products (price) VALUES (10.99);
    INSERT INTO products (price) VALUES (-5.75);
  

• Select all rows from the “products” table:

    SELECT * FROM products;
  

• The result would be:

price
10.99
-5.75

Comparison and Arithmetic Operations

The REAL data type also supports comparison and arithmetic operations, just like other numeric data types in PostgreSQL.

Here are some examples:

• Comparison:

    SELECT * FROM products WHERE price > 0;
    SELECT * FROM products WHERE price < 0;
    SELECT * FROM products WHERE price = 10.99;
  

• Arithmetic Operations:

    SELECT price + 5.5 FROM products;
    SELECT price - 2.25 FROM products;
    SELECT price * 2 FROM products;
    SELECT price / 3 FROM products;
  

Conclusion

The REAL data type in PostgreSQL is a useful way to store single-precision floating-point numbers. It allows you to represent a wide range of values and perform various operations on them. By understanding how to work with the REAL data type, you can effectively manage numeric data in your PostgreSQL database.