ModelQuery: add union()

package.json

@@ -1,6 +1,6 @@
 {
   "name": "wms-core",
-  "version": "0.22.0-rc.2",
+  "version": "0.22.0-rc.3",
   "description": "Node web application framework and toolbelt.",
   "repository": "https://gitlab.com/ArisuOngaku/wms-core",
   "author": "Alice Gaudon <alice@gaudon.pro>",

src/db/ModelQuery.ts

@@ -42,6 +42,7 @@ export default class ModelQuery<M extends Model> implements WhereFieldConsumer<M
     private _sortDirection?: 'ASC' | 'DESC';
     private readonly relations: string[] = [];
     private _pivot?: string[];
+    private _union?: ModelQueryUnion;
     private _recursiveRelation?: RelationDatabaseProperties;
 
     private constructor(type: QueryType, factory: ModelFactory<M>, fields?: SelectFields) {
@@ -94,7 +95,7 @@ export default class ModelQuery<M extends Model> implements WhereFieldConsumer<M
         return this;
     }
 
-    public sortBy(field: string, direction: 'ASC' | 'DESC' = 'ASC', raw: boolean = false): this {
+    public sortBy(field: string, direction: SortDirection = 'ASC', raw: boolean = false): this {
         this._sortBy = raw ? field : field.split('.').map(v => v.startsWith('`') ? v : `\`${v}\``).join('.');
         this._sortDirection = direction;
         return this;
@@ -113,6 +114,18 @@ export default class ModelQuery<M extends Model> implements WhereFieldConsumer<M
         return this;
     }
 
+    public union(query: ModelQuery<any>, sortBy: string, direction: SortDirection = 'ASC', raw: boolean = false, limit?: number): this {
+        if (this.type !== QueryType.SELECT) throw new Error('Union queries are only implemented with SELECT.');
+
+        this._union = {
+            query: query,
+            sortBy: raw ? sortBy : sortBy.split('.').map(v => v.startsWith('`') ? v : `\`${v}\``).join('.'),
+            direction: direction,
+            limit: limit,
+        };
+        return this;
+    }
+
     public recursive(relation: RelationDatabaseProperties): this {
         if (this.type !== QueryType.SELECT) throw new Error('Recursive queries are only implemented with SELECT.');
         this._recursiveRelation = relation;
@@ -166,8 +179,7 @@ export default class ModelQuery<M extends Model> implements WhereFieldConsumer<M
 
         let orderBy = '';
         if (typeof this._sortBy === 'string') {
-            orderBy = ` ORDER BY ${this._sortBy}`
-                + (this._sortDirection ? ' ' + this._sortDirection : '');
+            orderBy = ` ORDER BY ${this._sortBy} ${this._sortDirection!}`;
         }
 
         const table = `\`${this.table}\``;
@@ -184,6 +196,12 @@ export default class ModelQuery<M extends Model> implements WhereFieldConsumer<M
                 } else {
                     query = `SELECT ${fields} FROM ${table}${join}${where}${orderBy}${limit}`;
                 }
+
+                if (this._union) {
+                    const unionOrderBy = this._union.sortBy ? ` ORDER BY ${this._union.sortBy} ${this._union.direction}` : '';
+                    const unionLimit = typeof this._union.limit === 'number' ? ` LIMIT ${this._union.limit}` : '';
+                    query = `(${query}) UNION ${this._union.query.toString(false)}${unionOrderBy}${unionLimit}`;
+                }
                 break;
             case QueryType.UPDATE:
                 query = `UPDATE ${table} SET ${fields}${where}${orderBy}${limit}`;
@@ -418,3 +436,12 @@ interface WhereFieldConsumer<M extends Model> {
 }
 
 export type SelectFields = (string | SelectFieldValue | UpdateFieldValue)[];
+
+export type SortDirection = 'ASC' | 'DESC';
+
+type ModelQueryUnion = {
+    query: ModelQuery<any>,
+    sortBy: string,
+    direction: SortDirection,
+    limit?: number,
+};

test/ModelQuery.test.ts

@@ -58,4 +58,12 @@ describe('Test ModelQuery', () => {
         expect(query.toString(true)).toBe("WITH RECURSIVE cte AS (SELECT `model`.* FROM `model` WHERE `f1`=? UNION SELECT o.* FROM `model` AS o, cte AS c WHERE o.`foreign`=c.`local`) SELECT * FROM cte LEFT JOIN `test` ON `model`.`j1`=`test`.`j2` ORDER BY `f2` ASC LIMIT 8");
         expect(query.variables).toStrictEqual(['v1']);
     });
+
+    test('union queries', () => {
+        const query = ModelQuery.select({table: 'model'} as unknown as ModelFactory<Model>, '*');
+        const query2 = ModelQuery.select({table: 'model2'} as unknown as ModelFactory<Model>, '*');
+        query.union(query2, 'model.f1', 'DESC', false, 8);
+
+        expect(query.toString(true)).toBe("(SELECT `model`.* FROM `model`) UNION (SELECT `model2`.* FROM `model2`) ORDER BY `model`.`f1` DESC LIMIT 8");
+    });
 });