---
title: Quotation
description: Single quotation marks (') are used in the string literal syntax. Double quotation marks (") are used to quote identifiers.
url: https://docs.influxdata.com/influxdb3/clustered/reference/influxql/quoting/
estimated_tokens: 586
product: InfluxDB Clustered
version: clustered
---

# Quotation

InfluxQL supports both single and double quotation marks, but they each function differently and serve different purposes.

-   [Single quotes](#single-quotes)
-   [Double quotes](#double-quotes)

## Single quotes

Use single quotation marks (`'`) in the [string literal](/influxdb3/clustered/reference/influxql/#strings) and [timestamp literal](/influxdb3/clustered/reference/influxql/#dates--times) syntax.

In the following example, the `WHERE` clause evaluates the value of the `room` tag. Tags only contain string values, so the right operand of the predicate expression should be a string literal.

```sql
... WHERE room = 'Kitchen'
```

## Double quotes

Use double quotation marks (`"`) to quote [identifiers](/influxdb3/clustered/reference/influxql/#identifiers). Identifiers **must** be double-quoted in the following cases:

-   The identifier contains non-word characters. Word characters are defined as `[a-z,A-Z,0-9,_]`.
-   The identifier is case-sensitive.
-   The identifier contains [InfluxQL keywords](/influxdb3/clustered/reference/influxql/#keywords).
-   The identifier begins with a digit.

Double-quoted identifiers can also:

-   Contain any Unicode character except for a new line.
-   Contain escaped `"` characters (for example: `\"`).
-   Include [InfluxQL keywords](/influxdb3/clustered/reference/influxql/#keywords).

**While not always necessary, we recommend that you double quote identifiers.**

InfluxQL quoting guidelines differ from [line protocol quoting guidelines](/influxdb3/clustered/reference/syntax/line-protocol/#quotes).