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The existing docs have 254 findings from our shared Vale rules. Contributors would otherwise inherit these when editing the same lines. Clean up the prose across 80 pages: correct product names and a repeated word, simplify a few phrases, and replace dashes with punctuation that fits each sentence. The pinned Vale scan now reports zero findings, with no suppressions.
107 lines
4.5 KiB
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107 lines
4.5 KiB
Plaintext
---
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title: "SQL reference"
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sidebarTitle: "Overview"
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description: "SQL statements, expressions and data types supported by LanceDB Enterprise."
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icon: table-list
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keywords: ["sql", "datafusion", "flight sql", "reference", "dialect"]
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---
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LanceDB Enterprise supports SQL through an Arrow Flight SQL endpoint. This
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reference covers statement syntax, data types and expressions. To set up a
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client and run your first query, see [SQL](/basics/sql).
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## The dialect {#dialect}
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LanceDB uses [Apache DataFusion](https://datafusion.apache.org) for SQL planning
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and execution. These pages describe LanceDB's supported statements and
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extensions. DataFusion's reference is useful for expression syntax, but does
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not establish that every DataFusion statement or feature is exposed by
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LanceDB.
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## Connecting {#connecting}
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Use Python's `execute_query` or a Flight SQL client after configuring the
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[Enterprise connection](/basics/sql#sql-is-remote). TypeScript applications
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use a Flight SQL client for SQL queries.
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```python
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reader = db.execute_query("SELECT id, text FROM my_docs LIMIT 10")
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for batch in reader:
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print(batch)
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```
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SQL results arrive as Arrow record batches. Iterating over the reader avoids
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collecting the entire result in application memory. See
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[Queries](/basics/query) for result handling.
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## Usage {#usage}
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The endpoint executes one statement per request and is meant for the queries
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and DDL/DML pages below. Reach for the SDKs instead for table-management
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operations that have no SQL form, such as a merge insert. See
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[What SQL cannot do](#cannot).
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## Reference {#reference}
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### DDL, by object {#ddl}
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| [Namespace](/sql/ddl/namespace) | `CREATE SCHEMA`, `DROP SCHEMA` |
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| [Table](/sql/ddl/table) | `CREATE`, `DESCRIBE`, `ALTER`, `CLONE`, `DROP TABLE` |
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| [View](/sql/ddl/view) | `CREATE VIEW`, `DROP VIEW` |
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| [Materialized view](/sql/ddl/materialized-view) | `CREATE MATERIALIZED VIEW`, `SHOW MATERIALIZED VIEWS` |
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| [Index](/sql/ddl/index) | `CREATE INDEX`, `DROP INDEX` |
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| [Job](/sql/ddl/job) | `SHOW JOBS`, `SHOW ERRORS`, `PAUSE`/`RESUME`/`CANCEL JOB` |
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{/*
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Draft for the Functions release. Add this row to the table above, after Index:
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| [Function](/sql/ddl/function) | `CREATE FUNCTION`, `SHOW FUNCTIONS`, `DROP FUNCTION` |
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*/}
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### DML {#dml}
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| --- | --- |
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| [Insert](/sql/dml/insert) | `INSERT INTO`, including `INSERT ... SELECT` |
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| [Update](/sql/dml/update) | `UPDATE ... SET` |
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| [Delete](/sql/dml/delete) | `DELETE FROM` |
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| [Copy](/sql/dml/copy) | `COPY` (refused by recent deployment versions) |
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| [Refresh](/sql/dml/refresh) | filling computed columns and materialized views |
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### DQL {#dql}
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| --- | --- |
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| [Data types](/sql/data-types) | how Lance columns appear to SQL, and pseudo-columns |
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| [Select](/sql/dql/select) | projection, filtering, ordering, set operations, CTEs |
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| [Subqueries](/sql/dql/subqueries) | scalar, `IN`, `EXISTS`, correlated, derived tables |
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| [Joins](/sql/dql/join) | inner, outer, cross, and namespace-qualified paths |
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| [Aggregation](/sql/dql/aggregation) | `GROUP BY`, `HAVING`, the aggregate set |
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| [Window functions](/sql/dql/window) | `OVER`, framing, ranking and offset functions |
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| [Sampling](/sql/dql/sampling) | `TABLESAMPLE`, by rows or by fragments |
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| [Full-Text Search](/sql/dql/fts) | the `fts()` table function, and its query forms |
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| [Explain](/sql/dql/explain) | `EXPLAIN`, `EXPLAIN ANALYZE`, `EXPLAIN VERBOSE` |
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### Expressions {#expressions}
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| --- | --- |
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| [Operators](/sql/operators) | comparison, logical, arithmetic, literals, precedence |
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| [Functions](/sql/functions) | where to find each kind, and table functions |
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| [Scalar functions](/sql/scalar-functions) | the per-row catalogue, and what Lance accelerates |
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| [Prepared statements](/sql/prepared-statements) | preparing through a Flight SQL client |
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## SQL limitations and alternatives {#cannot}
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| Vector search | See [SQL vector search](/basics/sql#no-vector-sql) for supported query forms and server-version requirements. The [SDK query builder](/search/vector-search) also supports vector search. |
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| Merge insert | no SQL form: it needs a source relation and a per-match policy |
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| `information_schema` | not enabled, so `SHOW TABLES` and `SHOW COLUMNS` fail |
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| `COPY` | refused by recent deployment versions (see [Copy](/sql/dml/copy)) |
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| `PREPARE` / `EXECUTE` | preparation is a [protocol feature](/sql/prepared-statements), not a statement |
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| Run on a local database | no engine to plan the statement |
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See [Limits](/basics/limits#sql) for the bounds these pages enforce.
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