Threshold filtering
Filtering records by a threshold such as a timestamp, number, or other comparable column value.
Drizzle ORM · Function
lt
lt creates a strict less-than filter condition in Drizzle ORM. Use it in where clauses to select rows whose column value is below a supplied value.
How it works
Import lt from drizzle-orm and pass a column plus a comparison value. It creates a less-than condition that can be supplied to a query's where clause, including relational query filters.
Syntax
lt(column, value)Parameters
| Name | Type | Description |
|---|---|---|
column | Column or SQL expression | The table column or SQL expression to compare. |
value | Comparable value | The comparison value, represented as n in the documentation. |
Returns
A SQL filter condition representing a strict less-than comparison.
Key points
- Drizzle provides filter operators across its supported SQL dialects.
- The operator is imported from the main
drizzle-ormpackage. ltmatches values strictly below the comparison value.
Common mistakes
- The comparison is strict: rows equal to the supplied value do not match.
Example: Filter by a value less than a column value
import { lt } from 'drizzle-orm';
import { users } from './schema';
const olderUsers = await db
.select()
.from(users)
.where(lt(users.createdAt, new Date('2024-01-01')));Selects users whose creation timestamp is earlier than the supplied date.
When to use it
Cursor pagination
Selecting the preceding page when implementing descending cursor-based pagination.
Nested relation filtering
Restricting nested relational records through a relational query where callback.
Interview questions
QWhat does lt do?
lt is Drizzle's less-than filter operator. It receives a column and a value, then produces a condition suitable for a query's where clause.
Follow-up: How would you express the opposite comparison? Use gt when the column value must be greater than the supplied value.
QHow is lt used in a query?
Import it from drizzle-orm, then call lt(table.column, value) inside .where(...). The result can be combined with other filter operators when building a query.
Follow-up: How can it be used for descending cursor pagination? Use lt to select rows whose cursor is below the current cursor, together with descending ordering.
QWhat is a practical use for lt?
The operator compares a selected column against the provided value and matches values below it. The documentation also shows it in relational query filters for nested records.
Follow-up: What should the cursor property be for reliable cursor comparison? The documentation recommends that a cursor be unique and sequential.
Related
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