docs-v2/content/v2.0/reference/syntax/delete-predicate.md

82 lines
2.8 KiB
Markdown

---
title: Delete predicate syntax
list_title: Delete predicate
description: >
The InfluxDB `/delete` endpoint uses an InfluxQL-like predicate syntax to determine
what data points to delete.
menu:
v2_0_ref:
parent: Syntax
name: Delete predicate
weight: 104
v2.0/tags: [syntax, delete]
related:
- /v2.0/reference/cli/influx/delete/
---
The InfluxDB `/delete` endpoint uses an InfluxQL-like predicate syntax to determine
what data [points](/v2.0/reference/glossary/#point) to delete.
InfluxDB uses the delete predicate to evaluate the [series keys](/v2.0/reference/glossary/#series-key)
of points in the time range specified in the delete request.
Points with series keys that evaluate to `true` for the given predicate are deleted.
Points with series keys that evaluate to `false` are preserved.
A delete predicate is comprised of one or more [predicate expressions](/v2.0/reference/glossary/#predicate-expression).
The left operand of the predicate expression is the column name.
The right operand is the column value.
Operands are compared using [comparison operators](#comparison-operators).
Use [logical operators](#logical-operators) to combine two or more predicate expressions.
##### Example delete predicate
```sql
key1="value1" AND key2="value"
```
{{% note %}}
Predicate expressions can use any column or tag except `_time` or `_value`.
{{% /note %}}
## Logical operators
Logical operators join two or more predicate expressions.
| Operator | Description |
|:-------- |:----------- |
| `AND` | Both left and right operands must be `true` for the expression to be `true`. |
## Comparison operators
Comparison operators compare left and right operands and return `true` or `false`.
| Operator | Description | Example | Result |
|:-------- |:----------- |:-------: |:------:|
| `=` | Equal to | `"abc"="abc"` | `true` |
## Delete predicate examples
### Delete points with a specific measurement
The following will delete points in the `sensorData` measurement:
```sql
_measurement="sensorData"
```
### Delete points with a specific field
The following will delete points with the `temperature` field:
```sql
_field="temperature"
```
### Delete points with a specific tag set
The following will delete points from the `prod-1.4` host in the `us-west` region:
```sql
host="prod-1.4" AND region="us-west"
```
## Limitations
The delete predicate syntax has the following limitations.
- Delete predicates do not support regular expressions.
- Delete predicates do not support the `OR` logical operator.
- Delete predicates only support equality (`=`), not inequality (`!=`).
- Delete predicates can use any column or tag except `_time` or `_value`.