feat: support virtual columns in entity schema (#11597)

* feat: add entity mode virtual-property

* test: virtual columns

src/decorator/options/ColumnOptions.ts

@@ -187,4 +187,11 @@ export interface ColumnOptions extends ColumnCommonOptions {
      * SRID (Spatial Reference ID (EPSG code))
      */
     srid?: number
+
+    /**
+     * Query to be used to populate the column data. This query is used when generating the relational db script.
+     * The query function is called with the current entities alias either defined by the Entity Decorator or automatically
+     * @See https://typeorm.io/decorator-reference#virtualcolumn for more details.
+     */
+    query?: (alias: string) => string
 }

src/entity-schema/EntitySchemaColumnOptions.ts

@@ -44,6 +44,11 @@ export interface EntitySchemaColumnOptions extends SpatialColumnOptions {
      */
     treeLevel?: boolean
 
+    /**
+     * Indicates if this column is a virtualProperty column.
+     */
+    virtualProperty?: boolean
+
     /**
      * Column type. Must be one of the value from the ColumnTypes class.
      */
@@ -214,4 +219,11 @@ export interface EntitySchemaColumnOptions extends SpatialColumnOptions {
      * Foreign key options of this column.
      */
     foreignKey?: EntitySchemaColumnForeignKeyOptions
+
+    /**
+     * Query to be used to populate the column data. This query is used when generating the relational db script.
+     * The query function is called with the current entities alias either defined by the Entity Decorator or automatically
+     * @See https://typeorm.io/decorator-reference#virtualcolumn for more details.
+     */
+    query?: (alias: string) => string
 }

src/entity-schema/EntitySchemaTransformer.ts

@@ -98,6 +98,7 @@ export class EntitySchemaTransformer {
             if (regularColumn.treeChildrenCount) mode = "treeChildrenCount"
             if (regularColumn.treeLevel) mode = "treeLevel"
             if (regularColumn.objectId) mode = "objectId"
+            if (regularColumn.virtualProperty) mode = "virtual-property"
 
             const columnArgs: ColumnMetadataArgs = {
                 target: options.target || options.name,
@@ -135,6 +136,7 @@ export class EntitySchemaTransformer {
                     transformer: regularColumn.transformer,
                     spatialFeatureType: regularColumn.spatialFeatureType,
                     srid: regularColumn.srid,
+                    query: regularColumn.query,
                 },
             }
             metadataArgsStorage.columns.push(columnArgs)

test/functional/entity-schema/columns/virtual-columns/entity/Activity.ts

@@ -0,0 +1,22 @@
+import { EntitySchema } from "../../../../../../src"
+
+export const Activity = new EntitySchema({
+    name: "activities",
+    columns: {
+        id: {
+            primary: true,
+            generated: "increment",
+            type: "int",
+            unsigned: true,
+        },
+        k1: {
+            type: "int",
+        },
+        vK1: {
+            type: "int",
+            virtualProperty: true,
+            query: (alias) =>
+                `SELECT k1 FROM "activities" WHERE "k1" = ${alias}."k1"`,
+        },
+    },
+})

test/functional/entity-schema/columns/virtual-columns/virtual-columns.ts

@@ -0,0 +1,35 @@
+import "reflect-metadata"
+
+import { Activity } from "./entity/Activity"
+import {
+    closeTestingConnections,
+    createTestingConnections,
+    reloadTestingDatabases,
+} from "../../../../utils/test-utils"
+import { DataSource } from "../../../../../src"
+import { expect } from "chai"
+
+describe("entity-schema > columns > virtual column", () => {
+    let connections: DataSource[]
+    before(
+        async () =>
+            (connections = await createTestingConnections({
+                entities: [<any>Activity],
+                enabledDrivers: ["better-sqlite3"],
+            })),
+    )
+    beforeEach(() => reloadTestingDatabases(connections))
+    after(() => closeTestingConnections(connections))
+
+    it("should query virtual columns", () => {
+        return Promise.all(
+            connections.map(async (connection) => {
+                const repo = connection.getRepository(Activity)
+                await repo.save({ id: 0, k1: 1 })
+                const result = (await repo.findOne({ where: { id: 0 } }))!
+                expect(result.vK1).eq(result.k1)
+                expect(result.vK1).eq(1)
+            }),
+        )
+    })
+})