Datatypes in SQL

Datatypes are used to define the type of data that a column can hold in a table. SQL supports a wide range of datatypes, which can be broadly classified into the following categories:

1. Numeric Datatypes
2. Character Datatypes
3. Date and Time Datatypes
4. Binary Datatypes
5. Miscellaneous Datatypes

Let's take a look at each of these categories in detail.

1. Numeric Datatypes

Numeric datatypes are used to store numeric values. The following are some of the commonly used numeric datatypes in SQL:

• INT: Used to store integer values.
• DECIMAL(p, s): Used to store fixed-point numbers with p digits in total, s of which are after the decimal point.
• FLOAT(p): Used to store floating-point numbers with p digits of precision.
• REAL: Used to store floating-point numbers with single precision.
• DOUBLE PRECISION: Used to store floating-point numbers with double precision.

2. Character Datatypes

Character datatypes are used to store character strings. The following are some of the commonly used character datatypes in SQL:

• CHAR(n): Used to store fixed-length character strings of length n.
• VARCHAR(n): Used to store variable-length character strings of maximum length n.
• TEXT: Used to store large character strings.

3. Date and Time Datatypes

Date and time datatypes are used to store date and time values. The following are some of the commonly used date and time datatypes in SQL:

• DATE: Used to store date values in the format YYYY-MM-DD.
• TIME: Used to store time values in the format HH:MM:SS.
• TIMESTAMP: Used to store date and time values in the format YYYY-MM-DD HH:MM:SS.

4. Binary Datatypes

Binary datatypes are used to store binary data. The following are some of the commonly used binary datatypes in SQL:

• BINARY(n): Used to store fixed-length binary data of length n. Ex: BINARY(16) for storing UUID.
• VARBINARY(n): Used to store variable-length binary data of maximum length n. Ex: VARBINARY(255) for storing images.
• BLOB: Used to store large binary data. Ex: BLOB for storing files.

5. Miscellaneous Datatypes

There are several other datatypes that are used for specific purposes. Some of the commonly used miscellaneous datatypes in SQL are:

• BOOLEAN: Used to store boolean values (TRUE or FALSE).
• ENUM: Used to store one of a predefined list of values.
• SET: Used to store a set of values chosen from a predefined list.