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lancedb/docs/web/ingestion/index.mdx
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Brendan Clement 8cdff48859 docs: repair six links to anchors that no longer exist
Found by `mint broken-links --check-anchors` on the assembled site. Three
point at sections that were renamed or moved: the tag-versioning heading,
the branches comparison table, and the table-creation patterns, which now
live on the Create a table page. Three named sections that no longer exist
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---
title: "Ingesting data"
sidebarTitle: "Overview"
description: "Getting data into a table: creating one from your data, and the four write operations that follow."
icon: inbox
keywords: ["ingest", "create table", "add", "insert", "arrow", "pandas", "polars", "pydantic"]
---
import {
PyUpdateConnectEnterprise as UpdateConnectEnterprise,
PyUpdateConnectLocal as UpdateConnectLocal,
PyUpdateExampleTableSetup as UpdateExampleTableSetup,
TsUpdateConnectEnterprise,
TsUpdateConnectLocal,
TsUpdateExampleTableSetup,
RsUpdateConnectEnterprise,
RsUpdateConnectLocal,
RsUpdateExampleTableSetup,
RsUpdateMakeUsersReader,
} from '/snippets/tables.mdx';
In LanceDB, tables store records with a defined schema that specifies column
names and types. Across the SDKs, you can create tables from row-oriented data
and Apache Arrow data structures. The Python SDK additionally supports PyArrow
schemas for explicit schema control, and `LanceModel` for Pydantic-based
validation.
Getting data in has two halves: creating a table from data you already have, and
writing to a table that exists. This page covers the first and introduces the
second.
<Note>
Every operation here has a SQL form -- see [DML](/sql#dml).
</Note>
Start by [creating a table](/ingestion/create-table); the rest of this
section writes to one that exists.
## Choose a write method {#choose-a-write-method}
| Family | Method | Use this when... |
| --------------- | --------------- | ---------------- |
| [`add`](/ingestion/insert) | `add(data)` | You are appending new rows and do not need to match against existing ones. |
| `update` | `update(where=..., values=...)` | You want to edit rows that already exist, using a SQL filter. |
| `merge_insert` | `.when_matched_update_all()` | You have incoming rows and want to update keys that already exist in the table. |
| `merge_insert` | `.when_not_matched_insert_all()` | You have incoming rows and want to insert keys that do not exist yet. |
| `merge_insert` | `.when_matched_update_all()` + `.when_not_matched_insert_all()` | You want both behaviors together (often called **upsert**: update existing keys **and** insert missing keys in the same operation). |
| `merge_insert` | `.when_not_matched_by_source_delete(...)` | You want to remove target rows that are missing from the incoming source set. |
Write operations return status metadata. For example, `update` reports updated row count and
committed `version`, `delete` reports deleted row count and `version`, and `merge_insert` reports
inserted, updated, deleted, retry-attempt, and `version` fields. Writes require a mutable table
handle; after checking out an older version for reads, call `checkout_latest` / `checkoutLatest`
before modifying data.
The committed `version` advances even for writes that affect zero rows, such as a delete predicate
that matches nothing.
## Connect to LanceDB {#connect-to-lancedb}
Connect to your local LanceDB instance:
<CodeGroup>
<CodeBlock filename="Python" language="Python" icon="python">
{UpdateConnectLocal}
</CodeBlock>
<CodeBlock filename="TypeScript" language="TypeScript" icon="square-js">
{TsUpdateConnectLocal}
</CodeBlock>
<CodeBlock filename="Rust" language="Rust" icon="rust">
{RsUpdateConnectLocal}
</CodeBlock>
</CodeGroup>
Or, connect to LanceDB Enterprise:
<CodeGroup>
<CodeBlock filename="Python" language="Python" icon="python">
{UpdateConnectEnterprise}
</CodeBlock>
<CodeBlock filename="TypeScript" language="TypeScript" icon="square-js">
{TsUpdateConnectEnterprise}
</CodeBlock>
<CodeBlock filename="Rust" language="Rust" icon="rust">
{RsUpdateConnectEnterprise}
</CodeBlock>
</CodeGroup>
In the Rust snippets, a `make_users_reader` helper is used to build Arrow input data.
<CodeGroup>
<CodeBlock filename="Rust" language="Rust" icon="rust">
{RsUpdateMakeUsersReader}
</CodeBlock>
</CodeGroup>
## Create the example table {#create-the-example-table}
We'll start by creating a simple table with `id`, `name`, and `login_count` columns. All examples below use the same table.
<CodeGroup>
<CodeBlock filename="Python" language="Python" icon="python">
{UpdateExampleTableSetup}
</CodeBlock>
<CodeBlock filename="TypeScript" language="TypeScript" icon="square-js">
{TsUpdateExampleTableSetup}
</CodeBlock>
<CodeBlock filename="Rust" language="Rust" icon="rust">
{RsUpdateExampleTableSetup}
</CodeBlock>
</CodeGroup>
Expected table contents:
| id | name | login_count |
| --- | --- | --- |
| 1 | Alice | 10 |
| 2 | Bob | 20 |
The example above shows a PyArrow schema. You can just as well create the table using other
table creation patterns (Pandas, Polars, Pydantic, iterators, etc.) -- see [Create a table](/ingestion/create-table#create-a-table-with-data).