When working with SQL databases, it is important to understand the different data types available to effectively store and manipulate data. Each data type defines the kind of value that can be stored in a particular column of a table. In this article, we will explore the commonly used data types in SQL databases and their characteristics.

1. Numeric Data Types

Numeric data types are used to store numeric values such as integers, decimals, or floating-point numbers. Some commonly used numeric data types in SQL databases include:

• INT: Represents signed integers with a range of approximately -2 billion to 2 billion.
• DECIMAL(p, s): Represents fixed-point decimal numbers, where p specifies the total number of digits and s specifies the number of digits after the decimal point.
• FLOAT: Represents approximate floating point numbers with a wide range of values.
• BIGINT: Represents larger signed integers with a larger range compared to INT.

2. Character Data Types

Character data types are used to store text or string values in SQL databases. Some commonly used character data types include:

• VARCHAR(n): Represents variable-length character strings with a maximum length of n. The actual storage size depends on the length of the data.
• CHAR(n): Represents fixed-length character strings with a length of n. The storage size is always n characters.
• TEXT: Represents variable-length character strings with a very large maximum length.

3. Date and Time Data Types

Date and time data types are used to store temporal values such as dates, times, or timestamps. Some commonly used date and time data types include:

• DATE: Represents a date value in the format YYYY-MM-DD.
• TIME: Represents a time value in the format HH:MM:SS.
• DATETIME: Represents a combined date and time value in the format YYYY-MM-DD HH:MM:SS.
• TIMESTAMP: Represents a timestamp value, which is a unique identifier for a specific point in time.

4. Boolean Data Types

Boolean data types are used to store boolean values, which can be either true or false. Some SQL databases use different names for boolean data types, such as BIT, BOOL, or BOOLEAN.

Conclusion

Understanding the commonly used data types in SQL databases is crucial when defining the structure and constraints of database tables. By choosing the appropriate data types for your columns, you can ensure accurate storage and manipulation of data.