Class AndWrapper<DB, TB, T>

Change the output type of the expression.

This method call doesn't change the SQL in any way. This methods simply returns a copy of this AndWrapper with a new output type.

Combines this and another expression using AND.

See ExpressionWrapper.and for examples.

Combines this and another expression using AND.

See ExpressionWrapper.and for examples.

Returns an aliased version of the expression.

In addition to slapping as "the_alias" to the end of the SQL, this method also provides strict typing:

const result = await db
  .selectFrom('person')
  .select(eb =>
    eb('first_name', '=', 'Jennifer')
      .and('last_name', '=', 'Aniston')
      .as('is_jennifer_aniston')
  )
  .executeTakeFirstOrThrow()

// `is_jennifer_aniston: SqlBool` field exists in the result type.
console.log(result.is_jennifer_aniston)
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The generated SQL (PostgreSQL):

select "first_name" = $1 and "first_name" = $2 as "is_jennifer_aniston"
from "person"
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Returns an aliased version of the expression.

In addition to slapping as "the_alias" to the end of the SQL, this method also provides strict typing:

const result = await db
  .selectFrom('person')
  .select(eb =>
    eb('first_name', '=', 'Jennifer')
      .and('last_name', '=', 'Aniston')
      .as('is_jennifer_aniston')
  )
  .executeTakeFirstOrThrow()

// `is_jennifer_aniston: SqlBool` field exists in the result type.
console.log(result.is_jennifer_aniston)
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The generated SQL (PostgreSQL):

select "first_name" = $1 and "first_name" = $2 as "is_jennifer_aniston"
from "person"
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Creates the OperationNode that describes how to compile this expression into SQL.

Examples

If you are creating a custom expression, it's often easiest to use the sql template tag to build the node:

import { type Expression, type OperationNode, sql } from 'kysely'

class SomeExpression<T> implements Expression<T> {
  get expressionType(): T | undefined {
    return undefined
  }

  toOperationNode(): OperationNode {
    return sql`some sql here`.toOperationNode()
  }
}
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