Implemented SetRef #1413

src/parser/update-set-parser.ts

@@ -38,6 +38,14 @@ export type UpdateObjectExpression<
   UT extends keyof DB = TB,
 > = UpdateObject<DB, TB, UT> | UpdateObjectFactory<DB, TB, UT>
 
+export type UpdateObjectWithRef<
+  DB,
+  TB extends keyof DB,
+  UT extends keyof DB = TB,
+> = DrainOuterGeneric<{
+  [C in AnyColumn<DB, UT>]?: ReferenceExpression<DB, TB>
+}>
+
 export type ExtractUpdateTypeFromReferenceExpression<
   DB,
   TB extends keyof DB,
@@ -62,6 +70,36 @@ export function parseUpdate(
   return parseUpdateObjectExpression(args[0])
 }
 
+export function parseUpdateWithRef(
+  ...args:
+    | [ReferenceExpression<any, any>, ReferenceExpression<any, any>]
+    | [UpdateObjectWithRef<any, any, any>]
+): ReadonlyArray<ColumnUpdateNode> {
+  if (args.length === 2) {
+    return [
+      ColumnUpdateNode.create(
+        parseReferenceExpression(args[0]),
+        parseReferenceExpression(args[1]),
+      ),
+    ]
+  }
+
+  return parseUpdateObjectWithRef(args[0])
+}
+
+export function parseUpdateObjectWithRef(
+  update: UpdateObjectWithRef<any, any, any>,
+): ReadonlyArray<ColumnUpdateNode> {
+  return Object.entries(update)
+    .filter(([_, value]) => value !== undefined)
+    .map(([key, value]) => {
+      return ColumnUpdateNode.create(
+        ColumnNode.create(key),
+        parseReferenceExpression(value!),
+      )
+    })
+}
+
 export function parseUpdateObjectExpression(
   update: UpdateObjectExpression<any, any, any>,
 ): ReadonlyArray<ColumnUpdateNode> {

src/query-builder/update-query-builder.ts

@@ -38,8 +38,10 @@ import {
 import { UpdateQueryNode } from '../operation-node/update-query-node.js'
 import {
   UpdateObjectExpression,
+  UpdateObjectWithRef,
   ExtractUpdateTypeFromReferenceExpression,
   parseUpdate,
+  parseUpdateWithRef,
 } from '../parser/update-set-parser.js'
 import { Compilable } from '../util/compilable.js'
 import { QueryExecutor } from '../query-executor/query-executor.js'
@@ -743,6 +745,81 @@ export class UpdateQueryBuilder<DB, UT extends keyof DB, TB extends keyof DB, O>
     })
   }
 
+  /**
+   * Sets the values to update for an {@link Kysely.updateTable | update} query
+   * using column references instead of values.
+   *
+   * This method is similar to {@link set} but allows you to update columns by
+   * referencing other columns instead of providing literal values. This is useful
+   * when you want to copy values from one column to another or perform updates
+   * based on existing column values.
+   *
+   * You can provide either two arguments (column name and reference) or a single
+   * object where keys are column names and values are column references.
+   *
+   * ### Examples
+   *
+   * Update a column by referencing another column using the two-argument form:
+   *
+   * ```ts
+   * const result = await db
+   *   .updateTable('person')
+   *   .setRef('last_name', 'first_name')
+   *   .where('id', '=', 1)
+   *   .executeTakeFirst()
+   * ```
+   *
+   * The generated SQL (PostgreSQL):
+   *
+   * ```sql
+   * update "person" set "last_name" = "first_name" where "id" = $1
+   * ```
+   *
+   * You can reference columns from joined tables in a PostgreSQL `from` query:
+   *
+   * ```ts
+   * const result = await db
+   *   .updateTable('person')
+   *   .from('pet')
+   *   .setRef({
+   *     first_name: 'pet.name',
+   *   })
+   *   .whereRef('pet.owner_id', '=', 'person.id')
+   *   .executeTakeFirst()
+   * ```
+   *
+   * The generated SQL (PostgreSQL):
+   *
+   * ```sql
+   * update "person"
+   * set "first_name" = "pet"."name"
+   * from "pet"
+   * where "pet"."owner_id" = "person"."id"
+   * ```
+   */
+  setRef<RE extends ReferenceExpression<DB, UT>>(
+    key: RE,
+    value: RE,
+  ): UpdateQueryBuilder<DB, UT, TB, O>
+
+  setRef(
+    updates: UpdateObjectWithRef<DB, TB, UT>,
+  ): UpdateQueryBuilder<DB, UT, TB, O>
+
+  setRef(
+    ...args:
+      | [ReferenceExpression<DB, UT>, ReferenceExpression<DB, UT>]
+      | [UpdateObjectWithRef<DB, TB, UT>]
+  ): UpdateQueryBuilder<DB, UT, TB, O> {
+    return new UpdateQueryBuilder({
+      ...this.#props,
+      queryNode: UpdateQueryNode.cloneWithUpdates(
+        this.#props.queryNode,
+        parseUpdateWithRef(...args),
+      ),
+    })
+  }
+
   returning<SE extends SelectExpression<DB, TB>>(
     selections: ReadonlyArray<SE>,
   ): UpdateQueryBuilder<DB, UT, TB, ReturningRow<DB, TB, O, SE>>

test/node/src/update.test.ts

@@ -355,6 +355,96 @@ for (const dialect of DIALECTS) {
       expect(jennifer.last_name).to.equal('Jennifer')
     })
 
+    it('should update one row using setRef', async () => {
+      const query = ctx.db
+        .updateTable('person')
+        .setRef('last_name', 'first_name')
+        .where('first_name', '=', 'Jennifer')
+
+      testSql(query, dialect, {
+        postgres: {
+          sql: 'update "person" set "last_name" = "first_name" where "first_name" = $1',
+          parameters: ['Jennifer'],
+        },
+        mysql: {
+          sql: 'update `person` set `last_name` = `first_name` where `first_name` = ?',
+          parameters: ['Jennifer'],
+        },
+        mssql: {
+          sql: 'update "person" set "last_name" = "first_name" where "first_name" = @1',
+          parameters: ['Jennifer'],
+        },
+        sqlite: {
+          sql: 'update "person" set "last_name" = "first_name" where "first_name" = ?',
+          parameters: ['Jennifer'],
+        },
+      })
+
+      const result = await query.executeTakeFirst()
+
+      expect(result).to.be.instanceOf(UpdateResult)
+      expect(result.numUpdatedRows).to.equal(1n)
+      if (sqlSpec === 'mysql') {
+        expect(result.numChangedRows).to.equal(1n)
+      } else {
+        expect(result.numChangedRows).to.undefined
+      }
+
+      const jennifer = await ctx.db
+        .selectFrom('person')
+        .where('first_name', '=', 'Jennifer')
+        .select('last_name')
+        .executeTakeFirstOrThrow()
+
+      expect(jennifer.last_name).to.equal('Jennifer')
+    })
+
+    it('should update one row using setRef with object', async () => {
+      const query = ctx.db
+        .updateTable('person')
+        .setRef({
+          last_name: 'first_name',
+        })
+        .where('first_name', '=', 'Jennifer')
+
+      testSql(query, dialect, {
+        postgres: {
+          sql: 'update "person" set "last_name" = "first_name" where "first_name" = $1',
+          parameters: ['Jennifer'],
+        },
+        mysql: {
+          sql: 'update `person` set `last_name` = `first_name` where `first_name` = ?',
+          parameters: ['Jennifer'],
+        },
+        mssql: {
+          sql: 'update "person" set "last_name" = "first_name" where "first_name" = @1',
+          parameters: ['Jennifer'],
+        },
+        sqlite: {
+          sql: 'update "person" set "last_name" = "first_name" where "first_name" = ?',
+          parameters: ['Jennifer'],
+        },
+      })
+
+      const result = await query.executeTakeFirst()
+
+      expect(result).to.be.instanceOf(UpdateResult)
+      expect(result.numUpdatedRows).to.equal(1n)
+      if (sqlSpec === 'mysql') {
+        expect(result.numChangedRows).to.equal(1n)
+      } else {
+        expect(result.numChangedRows).to.undefined
+      }
+
+      const jennifer = await ctx.db
+        .selectFrom('person')
+        .where('first_name', '=', 'Jennifer')
+        .select('last_name')
+        .executeTakeFirstOrThrow()
+
+      expect(jennifer.last_name).to.equal('Jennifer')
+    })
+
     it('should update one row while ignoring undefined values', async () => {
       const query = ctx.db
         .updateTable('person')

test/typings/test-d/update.test-d.ts

@@ -47,6 +47,13 @@ async function testUpdate(db: Kysely<Database>) {
     .execute()
   expectType<{ fn: string; person_id: number }[]>(r5)
 
+  const r6 = await db
+    .updateTable('pet as p')
+    .where('p.id', '=', '1')
+    .setRef('name', 'species')
+    .executeTakeFirst()
+  expectType<UpdateResult>(r6)
+
   // Non-existent column
   expectError(
     db
@@ -55,6 +62,27 @@ async function testUpdate(db: Kysely<Database>) {
       .set({ name: 'Fluffy', not_a_column: 'not_a_column' }),
   )
 
+  expectError(
+    db
+      .updateTable('pet as p')
+      .where('p.id', '=', '1')
+      .setRef('name', 'not_a_column'),
+  )
+
+  expectError(
+    db
+      .updateTable('pet as p')
+      .where('p.id', '=', '1')
+      .setRef({ name: 'not_a_column' }),
+  )
+
+  expectError(
+    db
+      .updateTable('pet as p')
+      .where('p.id', '=', '1')
+      .setRef({ not_a_column: 'not_a_column' }),
+  )
+
   // Non-existent column in a callback
   expectError(
     db