Class AliasedExpressionWrapper<T, A>

A type that holds an expression and an alias for it.

AliasedExpression<T, A> can be used in places where, in addition to the value type T, you also need a name A for that value. For example anything you can pass into the select method needs to implement an AliasedExpression<T, A>. A becomes the name of the selected expression in the result and T becomes its type.

Examples

import {
  AliasNode,
  type AliasedExpression,
  type Expression,
  IdentifierNode
} from 'kysely'

class SomeAliasedExpression<T, A extends string> implements AliasedExpression<T, A> {
  #expression: Expression<T>
  #alias: A

  constructor(expression: Expression<T>, alias: A) {
    this.#expression = expression
    this.#alias = alias
  }

  get expression(): Expression<T> {
    return this.#expression
  }

  get alias(): A {
    return this.#alias
  }

  toOperationNode(): AliasNode {
    return AliasNode.create(
      this.#expression.toOperationNode(),
      IdentifierNode.create(this.#alias)
    )
  }
}
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