how to write the correct data type to a particular value?

PostgreSQL provides a wide range of data types to store different kinds of data. Choosing the correct data type for a value depends on the nature of the data and how you intend to use it. Below is a guide to match values with appropriate PostgreSQL data types:

1. Numeric Data Types

Integer Types: Use for whole numbers.
- SMALLINT: For very small numbers (e.g., -32,768 to 32,767).
- INTEGER or INT: For typical whole numbers (e.g., -2,147,483,648 to 2,147,483,647).
- BIGINT: For large whole numbers.
Decimal/Precision Numbers: Use for values requiring precision, like prices or measurements.
- NUMERIC(precision, scale): For exact precision. (e.g., NUMERIC(10, 2) for up to 10 digits, 2 after the decimal).
- REAL or FLOAT: For approximate floating-point numbers.
Serial Types: For auto-incrementing integers.
- SERIAL, BIGSERIAL: Use for primary keys.

2. Character Data Types

Fixed/Variable Length Strings:
- CHAR(n) or CHARACTER(n): For fixed-length strings. Pads with spaces if the input is shorter.
- VARCHAR(n) or CHARACTER VARYING(n): For variable-length strings with a maximum length.
- TEXT: For unlimited-length strings.

3. Boolean Data Type

BOOLEAN: Use for true/false values.
- Accepts TRUE, FALSE, NULL, or equivalents like 1 (true) and 0 (false).

4. Date/Time Data Types

Date:
- DATE: For calendar dates (e.g., 2024-11-16).
Time:
- TIME: For times of day (e.g., 14:30:00).
- TIME WITH TIME ZONE: Includes the time zone.
Timestamps:
- TIMESTAMP: For date and time together (e.g., 2024-11-16 14:30:00).
- TIMESTAMP WITH TIME ZONE: For date, time, and timezone.
Intervals:
- INTERVAL: For time intervals (e.g., 1 year 2 months).

5. JSON and JSONB

JSON: For storing JSON-formatted text (e.g., {"key": "value"}).
JSONB: For a binary JSON format, enabling faster queries and indexing.

6. Array Data Type

datatype[]: For storing arrays of a specific type (e.g., INTEGER[], TEXT[]).

7. Enumerated Types (ENUM)

ENUM: Define a static set of values (e.g., CREATE TYPE mood AS ENUM ('happy', 'sad', 'neutral');).

8. Geometric Data Types

For spatial data:
- POINT, LINE, CIRCLE, POLYGON.

9. Other Special Data Types

UUID: For universally unique identifiers.
BYTEA: For binary data like images or files.
ARRAY: For arrays of any data type.
XML: For storing XML data.

Examples:

Value	Recommended Data Type
`42`	`INTEGER`
`1234567890123`	`BIGINT`
`29.99`	`NUMERIC(5, 2)` or `REAL`
`'Hello, World!'`	`TEXT` or `VARCHAR(50)`
`TRUE` or `FALSE`	`BOOLEAN`
`2024-11-16`	`DATE`
`14:30:00`	`TIME`
`2024-11-16 14:30:00`	`TIMESTAMP`
`{'red', 'blue'}`	`TEXT[]`
`{"key": "value"}`	`JSON` or `JSONB`

Would you like help crafting SQL statements with these data types?

anonaba/_postgresql.md

PostgreSQL Notes