--- 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. Every operation here has a SQL form -- see [DML](/sql#dml). 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: {UpdateConnectLocal} {TsUpdateConnectLocal} {RsUpdateConnectLocal} Or, connect to LanceDB Enterprise: {UpdateConnectEnterprise} {TsUpdateConnectEnterprise} {RsUpdateConnectEnterprise} In the Rust snippets, a `make_users_reader` helper is used to build Arrow input data. {RsUpdateMakeUsersReader} ## 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. {UpdateExampleTableSetup} {TsUpdateExampleTableSetup} {RsUpdateExampleTableSetup} 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 [above](#create-a-table-with-data).