mirror of
https://github.com/lancedb/lancedb.git
synced 2026-10-12 14:52:26 +00:00
Brendan Clement
ac2db48af6
SQL is unavailable in the embedded library and varies on a deployment, which serves it only when its Flight SQL endpoint is enabled and reachable, and the SDK has to be told where that is. The page's opening badge goes. The SDKs page declares both offerings. Neither SDK aggregates or joins, so the parity tables no longer say they do, and views can be created through the SDKs on a deployment. Pages that said vector search has no SQL form now point to the version-dependent SQL form, and COPY, which newer deployment versions refuse, is marked as such in the reference.
82 lines
2.8 KiB
Plaintext
82 lines
2.8 KiB
Plaintext
---
|
|
title: "Operators and literals"
|
|
sidebarTitle: "Operators"
|
|
description: "Comparison, logical and arithmetic operators, literals, and precedence."
|
|
icon: plus-minus
|
|
keywords: ["operators", "literals", "precedence", "null", "cast", "interval"]
|
|
---
|
|
|
|
<Badge color="red">Enterprise</Badge> [SQL runs on a deployment.](/sql)
|
|
|
|
The operator set is DataFusion's. This page covers what is worth knowing when
|
|
the operands are Lance columns.
|
|
|
|
## Comparison {#comparison}
|
|
|
|
| | |
|
|
| --- | --- |
|
|
| `=` `!=` `<>` `<` `<=` `>` `>=` | ordinary comparison |
|
|
| `IS NULL` / `IS NOT NULL` | null test — `= NULL` is never true |
|
|
| `IS DISTINCT FROM` | comparison that treats null as a value |
|
|
| `BETWEEN a AND b` | inclusive range |
|
|
| `IN (...)` | set membership |
|
|
| `LIKE` / `ILIKE` | pattern match, `%` and `_` |
|
|
| `~` `~*` `!~` | regular expression match |
|
|
|
|
<Note>
|
|
For keyword matching on a text column, [`contains_tokens`](/sql/scalar-functions#contains-tokens)
|
|
is index-accelerated where `LIKE` is not. Reach for `LIKE` only when you need
|
|
its wildcard semantics.
|
|
</Note>
|
|
|
|
## Logical {#logical}
|
|
|
|
`AND`, `OR`, `NOT`. Three-valued: a comparison against null is **unknown**, and
|
|
`NOT unknown` is still unknown. A `WHERE` clause keeps only rows where the
|
|
predicate is true, so unknown behaves like false there — but not inside `NOT
|
|
IN`, which is the usual place this bites. See
|
|
[Subqueries](/sql/dql/subqueries#in-exists).
|
|
|
|
## Arithmetic {#arithmetic}
|
|
|
|
`+` `-` `*` `/` `%`, with the usual precedence. String concatenation is `||`.
|
|
|
|
<Warning>
|
|
Arithmetic over a vector column is **list** arithmetic, not scalar arithmetic —
|
|
a vector is a `FixedSizeList<Float32>`. When the operation you want is a
|
|
similarity comparison, use [vector search](/search/vector-search); whether SQL
|
|
can express it [depends on the deployment](/basics/sql#no-vector-sql).
|
|
</Warning>
|
|
|
|
## Literals {#literals}
|
|
|
|
| | |
|
|
| --- | --- |
|
|
| String | `'text'` — doubled quote to escape: `'it''s'` |
|
|
| Number | `42`, `3.14` |
|
|
| Boolean | `TRUE`, `FALSE` |
|
|
| Null | `NULL` |
|
|
| Date / timestamp | `DATE '2026-01-01'`, `TIMESTAMP '2026-01-01 12:00:00'` |
|
|
| Interval | `INTERVAL '7 days'` |
|
|
| Array | `[1, 2, 3]` |
|
|
|
|
Identifiers are quoted with double quotes when they need to be — a reserved word
|
|
or a name with mixed case: `SELECT "order" FROM "MyTable"`.
|
|
|
|
## Casting {#casting}
|
|
|
|
```sql
|
|
SELECT CAST(identifier AS VARCHAR), identifier::VARCHAR FROM documents
|
|
```
|
|
|
|
Both forms work. `TRY_CAST` returns null instead of erroring on a value that
|
|
will not convert, which is the one to use over a column you do not control.
|
|
|
|
## Precedence {#precedence}
|
|
|
|
Highest to lowest: `::` → unary `-` → `* / %` → `+ -` → `||` → comparison →
|
|
`IS` → `NOT` → `AND` → `OR`.
|
|
|
|
Parenthesize anything mixing `AND` and `OR`. `a OR b AND c` is `a OR (b AND c)`,
|
|
which is rarely what was meant.
|