How Do You Create a Table With Boolean Data Type in Oracle?

Creating a Table With Boolean Data Type in Oracle

When working with databases, it is common to come across scenarios where you need to store boolean values. In Oracle, there is no direct boolean data type like in some other database systems.

However, you can achieve the same functionality by using a number or a character data type with some additional constraints. Let’s explore how you can create a table with boolean data type in Oracle.

Using NUMBER Data Type

If you decide to use the NUMBER data type to represent boolean values, you can assign specific numeric values to represent true and false. For example, you can use 1 for true and 0 for false. Here’s an example of creating a table with a boolean column using the NUMBER data type:

CREATE TABLE employees (
    id NUMBER,
    name VARCHAR2(50),
    is_active NUMBER(1) CHECK (is_active IN (0, 1))
);

• Line 1: The CREATE TABLE statement begins by specifying the name of the table followed by the column definitions.
• Line 2: The “id” column is created with the NUMBER data type.
• Line 3: The “name” column is created with the VARCHAR2 data type.
• Line 4: The “is_active” column is created with the NUMBER data type and a constraint is added to restrict its values to either 0 or 1 using the CHECK clause.

Using VARCHAR2 Data Type

If you prefer to use character-based representation for boolean values, you can utilize the VARCHAR2 data type. In this case, you can assign specific characters like ‘Y’ for true and ‘N’ for false. Here’s an example of creating a table with a boolean column using the VARCHAR2 data type:

CREATE TABLE employees (
    id NUMBER,
    name VARCHAR2(50),
    is_active VARCHAR2(1) CHECK (is_active IN ('Y', 'N'))
);

• Line 1: The CREATE TABLE statement begins by specifying the name of the table followed by the column definitions.
• Line 4: The “is_active” column is created with the VARCHAR2 data type and a constraint is added to restrict its values to either ‘Y’ or ‘N’ using the CHECK clause.

Note:

In both cases, it is important to enforce appropriate constraints on the boolean columns to ensure that only valid values are stored. This helps maintain data consistency and integrity.

By using either the NUMBER or VARCHAR2 data types and applying suitable constraints, you can effectively create boolean columns in Oracle tables. Remember to choose an approach that aligns with your specific requirements and coding style.

Conclusion

In this tutorial, we explored how you can create a table with boolean data type in Oracle. We discussed two approaches: using NUMBER or VARCHAR2 data types.

It’s essential to apply constraints on these columns to ensure valid values are stored. By incorporating these techniques, you can effectively handle boolean values in your database tables.