## 5.4. Import CSV

This section describes procedures that can be used to import data from CSV files that comply with the Neo4j import tool’s header format.

CSV files that comply with the Neo4j import tool’s header format can be imported using the `apoc.import.csv` procedure. This procedure can be used to load small- to medium-sized data sets in an online database. For importing larger data sets, it is recommended to perform a batch import using the (import tool, which loads data in bulk to an offline (initially empty) database.

### 5.4.1. Usage

The parameters of the `apoc.import.csv(<nodes>, <relationships>, <config>)` procedure are as follows.

The `<nodes>` parameter is a list, where each element is a map defining a source file (`fileName`) to be loaded with a set of labels (`labels`):

name | description | example
--- | --- | ---
`fileName` | filename | `'file:/students.csv'`
`labels` | set of labels | `['Person', 'Student']`

The `<relationships>` parameter is also a list, where each element is a map defining a source file (`fileName`) to be loaded with a given relationship type (`type`):

name | description | example
--- | --- | ---
`fileName` | filename | `'file:/works_at.csv'`
`type` | relationship type | `'WORKS_AT'`

The `<config>` parameter is a map

name | description | default | import tool counterpart
--- | --- | --- | ---
`delimiter` | delimiter character between columns | `,` | `--delimiter=,`
`arrayDelimiter` | delimiter character in arrays | `;` | `--array-delimiter=;`
`ignoreDuplicateNodes` | for duplicate nodes, only load the first one and skip the rest (true) or fail the import (false) | `false` | `--ignore-duplicate-nodes=false`
`quotationCharacter` | quotation character | `"` | `--quote='"'`
`stringIds` | treat ids as strings | `true` | `--id-type=STRING`
`skipLines` | lines to skip (incl. header) | `1` | `N/A`

### 5.4.2. Examples for apoc.import.csv

#### 5.4.2.1. Loading nodes

Given the following CSV file and procedure call, the database loads two `Person` nodes with their `name` properties set:

persons.csv.

    name:STRING
    John
    Jane

    CALL apoc.import.csv([{fileName: 'file:/persons.csv', labels: ['Person']}], [], {})

#### 5.4.2.2. Loading nodes and relationships

Given the following CSV files and procedure call, the database loads two `Person` nodes and a `KNOWS` relationship between them (with the value of the `since` property set). Note that both the field terminators and the array delimiters are changed from the default value, and the CSVs use numeric ids.

persons.csv.

    :ID|name:STRING|speaks:STRING[]
    1|John|en,fr
    2|Jane|en,de

knows.csv.

    :START_ID|:END_ID|since:INT
    1|2|2016

    CALL apoc.import.csv(
      [{fileName: 'file:/persons.csv', labels: ['Person']}],
      [{fileName: 'file:/knows.csv', type: 'KNOWS'}],
      {delimiter: '|', arrayDelimiter: ',', stringIds: false}
    )

The loader supports advanced features of the import tool:

- ID spaces are supported, using the import tool’s syntax.
- Node labels can be specified with the `:LABEL` field.
- Relationship types can be specified with the `:TYPE` field.