Common data types¶

Choosing the correct data type for each column ensures data accuracy, efficiency, and reliability within the database. The following describes the purpose of a data type in Percona Server for MySQL:

Purpose:
Data types define the kind of data that can be stored in a column of a table.
They enforce constraints on the values that can be inserted into the column, ensuring data integrity.
Data types determine how the data is stored in memory and on disk, optimizing storage space and performance.
They provide a way to specify the format and range of acceptable values for numeric, string, date, and other types of data.
Data types facilitate efficient sorting, indexing, and searching of data within the database.
Importance:
Choosing the appropriate data type for each column is crucial for efficient database design and performance.
Data types help prevent data corruption and inconsistency by enforcing strict rules for data storage and manipulation.
They enable database administrators and developers to define the structure of the database accurately and ensure compatibility with application requirements.
Understanding data types allows for effective data modeling and schema design, leading to well-organized and scalable databases.

The following is a description of common data types:

Integer Types¶

Integers are whole numbers without any fractional part. Percona Server for MySQL offers different sizes of integer types to accommodate various ranges of values.

Data Type name	Description
`TINYINT`	A very small integer that can hold values from -128 to 127 (signed) or 0 to 255 (unsigned).
`SMALLINT`	A small integer that can hold values from -32768 to 32767 (signed) or 0 to 65535 (unsigned).
`MEDIUMINT`	A medium-sized integer that can hold values from -8388608 to 8388607 (signed) or 0 to 16777215 (unsigned).
`INT` or `INTEGER`	A standard-sized integer that can hold values from -2147483648 to 2147483647 (signed) or 0 to 4294967295 (unsigned).
`BIGINT`	A large integer that can hold values from -9223372036854775808 to 9223372036854775807 (signed) or 0 to 18446744073709551615 (unsigned).

Floating-Point Types¶

Floating-point types are used to represent numbers with a fractional part.

Data Type name	Description
`FLOAT`	A single-precision floating-point number that can hold up to 7 decimal digits of precision.
`DOUBLE` or `REAL`	A double-precision floating-point number that can hold up to 15 decimal digits of precision.

Fixed-Point Types¶

Fixed-point types are used to represent exact numeric values.

DECIMAL or NUMERIC: A fixed-point number with user-defined precision and scale.

String Types¶

String types are used to store text data.

Data Type name	Description
`CHAR`	A fixed-length string that can hold up to 255 characters.
`VARCHAR`	A variable-length string that can hold up to 65535 characters.
`TEXT`	A string with a maximum length of 65535 characters.
`BLOB`	A binary large object that can hold up to 65535 bytes.

Date and Time Types¶

Date and time types are used to store date and time information.

Data Type name	Description
`DATE`	A date value in the format YYYY-MM-DD.
`TIME`	A time value in the format HH:MM:SS.
`DATETIME`	A combination of date and time values in the format YYYY-MM-DD HH:MM:SS.
`TIMESTAMP`	A timestamp value representing the number of seconds since the Unix epoch (January 1, 1970).

Advanced SQL features¶

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Last update: 2024-12-18