opensearch-docs-cn/docs/sql/datatypes.md

---
layout: default
title: Data Types
parent: SQL
nav_order: 73
---

# Data types

The following table shows the data types supported by the SQL plugin and how each one maps to SQL and OpenSearch data types:

| OpenSearch SQL Type | OpenSearch Type | SQL Type
:--- | :--- | :---
boolean |	boolean |	BOOLEAN
byte |	byte |	TINYINT
short |	byte |	SMALLINT
integer |	integer |	INTEGER
long | long |	BIGINT
float |	float |	REAL
half_float | float | FLOAT
scaled_float | float | DOUBLE
double | double | DOUBLE
keyword |	string | VARCHAR
text | text | VARCHAR
date | timestamp | TIMESTAMP
ip | ip | VARCHAR
date | timestamp | TIMESTAMP
binary | binary | VARBINARY
object | struct | STRUCT
nested | array | STRUCT

In addition to this list, the SQL plugin also supports the `datetime` type, though it doesn't have a corresponding mapping with OpenSearch or SQL.
To use a function without a corresponding mapping, you must explicitly convert the data type to one that does.


## Date and time types

The date and time types represent a time period: `DATE`, `TIME`, `DATETIME`, `TIMESTAMP`, and `INTERVAL`. By default, the OpenSearch DSL uses the `date` type as the only date-time related type that contains all information of an absolute time point.

To integrate with SQL, each type other than the `timestamp` type holds part of the time period information. To use date-time functions, see [datetime](../functions#date-and-time). Some functions might have restrictions for the input argument type.


### Date

The `date` type represents the calendar date regardless of the time zone. A given date value is a 24-hour period, but this period varies in different timezones and might have flexible hours during daylight saving programs. The `date` type doesn't contain time information and it only supports a range of `1000-01-01` to `9999-12-31`.

| Type | Syntax | Range
:--- | :--- | :---
date | `yyyy-MM-dd` | `0001-01-01` to `9999-12-31`

### Time

The `time` type represents the time of a clock regardless of its timezone. The `time` type doesn't contain date information.

| Type | Syntax | Range
:--- | :--- | :---
time | `hh:mm:ss[.fraction]` | `00:00:00.000000` to `23:59:59.999999`

### Datetime

The `datetime` type is a combination of date and time. It doesn't contain timezone information. For an absolute time point that contains date, time, and timezone information, see [Timestamp](#timestamp).

| Type | Syntax | Range
:--- | :--- | :---
datetime | `yyyy-MM-dd hh:mm:ss[.fraction]` | `0001-01-01 00:00:00.000000` to `9999-12-31 23:59:59.999999`

### Timestamp

The `timestamp` type is an absolute instance independent of timezone or convention. For example, for a given point of time, if you change the timestamp to a different timezone, its value changes accordingly.

The `timestamp` type is stored differently from the other types. It's converted from its current timezone to UTC for storage and converted back to its set timezone from UTC when it's retrieved.

| Type | Syntax | Range
:--- | :--- | :---
timestamp | `yyyy-MM-dd hh:mm:ss[.fraction]` | `0001-01-01 00:00:01.000000` UTC to `9999-12-31 23:59:59.999999`

### Interval

The `interval` type represents a temporal duration or a period.

| Type | Syntax
:--- | :--- | :---
interval | `INTERVAL expr unit`

The `expr` unit is any expression that eventually iterates to a quantity value. It represents a unit for interpreting the quantity, including `MICROSECOND`, `SECOND`, `MINUTE`, `HOUR`, `DAY`, `WEEK`, `MONTH`, `QUARTER`, and `YEAR`. The `INTERVAL` keyword and the unit specifier are not case sensitive.

The `interval` type has two classes of intervals: year-week intervals and day-time intervals.

- Year-week intervals store years, quarters, months, and weeks.
- Day-time intervals store days, hours, minutes, seconds, and microseconds.


### Convert between date and time types

Apart from the `interval` type, all date and time types can be converted to each other. The conversion might alter the value or cause some information loss. For example, when extracting the `time` value from a `datetime` value, or converting a `date` value to a `datetime` value, and so on.

The SQL plugin supports the following conversion rules for each of the types:

**Convert from date**

- Because the `date` value doesn't have any time information, conversion to the `time` type isn't useful and always returns a zero time value of `00:00:00`.
- Converting from `date` to `datetime` has a data fill-up due to the lack of time information. It attaches the time `00:00:00` to the original date by default and forms a `datetime` instance. For example, conversion of `2020-08-17` to a `datetime` type is `2020-08-17 00:00:00`.
- Converting to `timestamp` type alternates both the `time` value and the `timezone` information. It attaches the zero time value `00:00:00` and the session timezone (UTC by default) to the date. For example, conversion of `2020-08-17` to a `datetime` type with a session timezone UTC is `2020-08-17 00:00:00 UTC`.

**Convert from time**

- You cannot convert the `time` type to any other date and time types because it doesn't contain any date information.

**Convert from datetime**

- Converting `datetime` to `date` extracts the date value from the `datetime` value. For example, conversion of `2020-08-17 14:09:00` to a `date` type is `2020-08-08`.
- Converting `datetime` to `time` extracts the time value from the `datetime` value. For example, conversion of `2020-08-17 14:09:00` to a `time` type is `14:09:00`.
- Because the `datetime` type doesn't contain timezone information, converting to `timestamp` type fills up the timezone value with the session timezone. For example, conversion of `2020-08-17 14:09:00` (UTC) to a `timestamp` type is `2020-08-17 14:09:00 UTC`.

**Convert from timestamp**

- Converting from a `timestamp` type to a `date` type extracts the date value and converting to a `time` type extracts the time value. Converting from a `timestamp` type to `datetime` type extracts only the `datetime` value and leaves out the timezone value. For example, conversion of `2020-08-17 14:09:00` UTC to a `date` type is `2020-08-17`, to a `time` type is `14:09:00`, and to a `datetime` type is `2020-08-17 14:09:00`.