types: allow EntityQuery to select from many tables (#62)

Doing `join` will bring in more tables that can be selected against. Thus, `EntityQuery.select` needs to be able pull from more than a single schema.

To do that, `EntityQuery` now takes a `FromSet` rather than `EntitySchema`.

```ts
type FromSet = {
  [table: string]: EntitySchema
};

const q = new EntityQuery<{issue: Issue}>();
const q2 = new EntityQuery<{user: User}>();

q.join(q2, 'owner', 'issue.ownerId', 'owner.id').select(...);
```

`join` requires us to support aliasing ambiguous columns so this adds that as well.

src/zql/ast-to-ivm/pipeline-builder.test.ts

@@ -27,7 +27,7 @@ type E1 = z.infer<typeof e1>;
 const context = makeTestContext();
 const comparator = (l: E1, r: E1) => compareUTF8(l.id, r.id);
 test('A simple select', () => {
-  const q = new EntityQuery<E1>(context, 'e1');
+  const q = new EntityQuery<{e1: E1}>(context, 'e1');
   const m = new Materialite();
   let s = m.newSetSource<E1>(comparator);
   let pipeline = buildPipeline(
@@ -69,7 +69,7 @@ test('A simple select', () => {
 });
 
 test('Count', () => {
-  const q = new EntityQuery<E1>(context, 'e1');
+  const q = new EntityQuery<{e1: E1}>(context, 'e1');
   const m = new Materialite();
   const s = m.newSetSource<E1>(comparator);
   const pipeline = buildPipeline(
@@ -99,7 +99,7 @@ test('Count', () => {
 });
 
 test('Where', () => {
-  const q = new EntityQuery<E1>(context, 'e1');
+  const q = new EntityQuery<{e1: E1}>(context, 'e1');
   const m = new Materialite();
   const s = m.newSetSource<E1>(comparator);
   const pipeline = buildPipeline(
@@ -133,7 +133,7 @@ describe('OR', () => {
 
   type Case = {
     name?: string | undefined;
-    where: WhereCondition<E>;
+    where: WhereCondition<{e1: E}>;
     values?: (E | DeleteE)[] | undefined;
     expected: (E | [v: E, multiplicity: number])[];
   };
@@ -377,7 +377,11 @@ describe('OR', () => {
 
       const ast: AST = {
         table: 'items',
-        select: ['id', 'a', 'b'],
+        select: [
+          ['id', 'id'],
+          ['a', 'a'],
+          ['b', 'b'],
+        ],
         where: c.where as Condition,
         orderBy: [['id'], 'asc'],
       };

src/zql/ast-to-ivm/pipeline-builder.ts

@@ -62,7 +62,7 @@ export function buildPipeline(
 
 export function applySelect(
   stream: DifferenceStream<Entity>,
-  select: string[],
+  select: [column: string, alias: string][],
   orderBy: Ordering | undefined,
 ) {
   return stream.map(x => {
@@ -71,8 +71,8 @@ export function applySelect(
       ret = {...x};
     } else {
       ret = {};
-      for (const field of select) {
-        ret[field] = (x as Record<string, unknown>)[field];
+      for (const selector of select) {
+        ret[selector[1]] = (x as Record<string, unknown>)[selector[0]];
       }
     }
 
@@ -168,7 +168,7 @@ function applyGroupBy<T extends Entity>(
   stream: DifferenceStream<T>,
   columns: string[],
   aggregations: Aggregation[],
-  select: string[],
+  select: [string, string][],
   orderBy: Ordering | undefined,
 ) {
   const keyFunction = makeKeyFunction(columns);
@@ -178,8 +178,8 @@ function applyGroupBy<T extends Entity>(
     values => {
       const first = values[Symbol.iterator]().next().value;
       const ret: Record<string, unknown> = {};
-      for (const column of select) {
-        ret[column] = first[column];
+      for (const selector of select) {
+        ret[selector[1]] = first[selector[0]];
       }
       addOrdering(ret, first, orderBy);
 

src/zql/ast/ast.ts

@@ -27,7 +27,7 @@ export type Aggregation = {
 export type AST = {
   readonly table?: string | undefined;
   readonly alias?: number | undefined;
-  readonly select?: string[] | undefined;
+  readonly select?: [string, string][] | undefined;
   readonly aggregate?: Aggregation[];
   // readonly subQueries?: {
   //   readonly alias: string;

src/zql/context/replicache-context.test.ts

@@ -140,7 +140,7 @@ test('ZQL query with Replicache', async () => {
   const r = newRep();
   const context = makeReplicacheContext(r);
 
-  const q = new EntityQuery<E1>(context, 'e1');
+  const q = new EntityQuery<{e1: E1}>(context, 'e1');
 
   const view = q.select('id').where('str', '>', 'm').prepare().view();
 

src/zql/integration.test.ts

@@ -84,7 +84,7 @@ function sampleTenUniqueIssues() {
 function setup() {
   const r = newRep();
   const c = makeReplicacheContext(r);
-  const q = new EntityQuery<Issue>(c, 'issue');
+  const q = new EntityQuery<{issue: Issue}>(c, 'issue');
   return {r, c, q};
 }
 

src/zql/ivm/view/tree-view.test.ts

@@ -17,7 +17,7 @@ test('asc and descComparator on Entities', () => {
 
   const updatedStream = applySelect(
     s.stream,
-    ['id'],
+    [['id', 'id']],
     [['n', 'id'], 'asc'],
   ) as unknown as DifferenceStream<Selected>;
 
@@ -29,7 +29,7 @@ test('asc and descComparator on Entities', () => {
     m,
     applySelect(
       s.stream as unknown as DifferenceStream<Entity>,
-      ['id'],
+      [['id', 'id']],
       [['n', 'id'], 'desc'],
     ) as unknown as DifferenceStream<Selected>,
     descComparator,

src/zql/query/condition-to-string.ts

@@ -1,8 +1,7 @@
-import {EntitySchema} from '../schema/entity-schema.js';
-import {WhereCondition} from './entity-query.js';
+import {FromSet, WhereCondition} from './entity-query.js';
 
-export function conditionToString<S extends EntitySchema>(
-  c: WhereCondition<S>,
+export function conditionToString<From extends FromSet>(
+  c: WhereCondition<From>,
   paren = false,
 ): string {
   if (c.op === 'AND' || c.op === 'OR') {