Stores universally unique identifiers
Posted: Thu May 22, 2025 9:46 am
In SQL, data types define the kind of data that can be stored in a table column. Choosing the correct data type is essential for data integrity, efficient storage, and accurate query processing. SQL supports a wide range of data types to accommodate various types of information such as numbers, text, dates, and binary data.
1. Numeric Data Types
These data types are used for storing numbers and performing mathematical operations.
INT / INTEGER: Stores whole numbers without decimals (e.g., 1, 100, -50).
SMALLINT / BIGINT: Stores smaller or larger whole numbers depending on memory requirements.
DECIMAL(p, s) / NUMERIC(p, s): Stores fixed-point numbers with precision (p = total digits, s = digits after the decimal point). Ideal for financial calculations.
FLOAT / REAL / DOUBLE: Stores approximate floating-point numbers. Useful for scientific calculations, but may introduce rounding errors.
2. Character and String Data Types
Used for storing text and alphanumeric characters.
CHAR(n): Fixed-length string. Pads unused space with blanks. Suitable for fields with consistent lengths (e.g., country codes).
VARCHAR(n): Variable-length string up to a defined limit. More storage-efficient than CHAR.
TEXT / CLOB: Stores large blocks of text. Used for comments, descriptions, or documents.
3. Date and Time Data Types
Handle temporal data like dates, times, and timestamps.
DATE: Stores year, month, and day (e.g., '2025-05-22').
TIME: Stores time in hours, minutes, and seconds (e.g., '14:30:00').
DATETIME / TIMESTAMP: Stores both date and time values.
INTERVAL: Represents a span of time (e.g., 3 days, 5 hours).
4. Boolean Data Type
BOOLEAN: Stores TRUE, FALSE, or NULL. Commonly iceland phone number list used in conditional logic or status flags.
5. Binary Data Types
Used to store binary objects like images, files, or media.
BINARY / VARBINARY: Fixed or variable-length binary data.
BLOB (Binary Large Object): Stores large binary data like images or multimedia files.
6. Other Special Data Types
ENUM (in MySQL): Allows a column to have one value from a predefined list.
UUID: .
Conclusion
Understanding and using the right SQL data types ensures data accuracy, minimizes storage costs, and improves database performance. Carefully planning your schema with appropriate data types is a fundamental step in robust database design.
1. Numeric Data Types
These data types are used for storing numbers and performing mathematical operations.
INT / INTEGER: Stores whole numbers without decimals (e.g., 1, 100, -50).
SMALLINT / BIGINT: Stores smaller or larger whole numbers depending on memory requirements.
DECIMAL(p, s) / NUMERIC(p, s): Stores fixed-point numbers with precision (p = total digits, s = digits after the decimal point). Ideal for financial calculations.
FLOAT / REAL / DOUBLE: Stores approximate floating-point numbers. Useful for scientific calculations, but may introduce rounding errors.
2. Character and String Data Types
Used for storing text and alphanumeric characters.
CHAR(n): Fixed-length string. Pads unused space with blanks. Suitable for fields with consistent lengths (e.g., country codes).
VARCHAR(n): Variable-length string up to a defined limit. More storage-efficient than CHAR.
TEXT / CLOB: Stores large blocks of text. Used for comments, descriptions, or documents.
3. Date and Time Data Types
Handle temporal data like dates, times, and timestamps.
DATE: Stores year, month, and day (e.g., '2025-05-22').
TIME: Stores time in hours, minutes, and seconds (e.g., '14:30:00').
DATETIME / TIMESTAMP: Stores both date and time values.
INTERVAL: Represents a span of time (e.g., 3 days, 5 hours).
4. Boolean Data Type
BOOLEAN: Stores TRUE, FALSE, or NULL. Commonly iceland phone number list used in conditional logic or status flags.
5. Binary Data Types
Used to store binary objects like images, files, or media.
BINARY / VARBINARY: Fixed or variable-length binary data.
BLOB (Binary Large Object): Stores large binary data like images or multimedia files.
6. Other Special Data Types
ENUM (in MySQL): Allows a column to have one value from a predefined list.
UUID: .
Conclusion
Understanding and using the right SQL data types ensures data accuracy, minimizes storage costs, and improves database performance. Carefully planning your schema with appropriate data types is a fundamental step in robust database design.