Add support for subqueries

orm/src/builder/type/Select.ts

@@ -4,7 +4,8 @@ import {
     WhereStatement,
     TableRef,
     OrderStatement,
-    OrderDirection, HavingStatement
+    OrderDirection, HavingStatement,
+    escape,
 } from '../types.ts'
 import {WhereBuilder} from './WhereBuilder.ts'
 import {applyMixins} from '../../../../lib/src/support/mixins.ts'
@@ -72,10 +73,13 @@ export class Select<T> extends ConnectionExecutable<T> {
         ].filter(x => String(x).trim()).join(`\n${indent}`)
     }
 
-    field(field: string) {
-        if ( !this._fields.includes(field) ) {
+    field(field: string | Select<any>, as?: string) {
+        if ( field instanceof Select ) {
+            this._fields.push(`${escape(field)}${as ? ' AS '+as : ''}`)
+        } else {
             this._fields.push(field)
         }
+
         return this
     }
 

orm/src/builder/types.ts

@@ -1,5 +1,6 @@
 import {WhereOperator} from '../../../lib/src/collection/Where.ts'
 import RawValue from './RawValue.ts'
+import {Select} from "./type/Select.ts";
 
 export type FieldSet = string | string[]
 export type QuerySource = string | { ref: QuerySource, alias: string }
@@ -20,7 +21,7 @@ export type HavingGroup = WhereGroup
 export type HavingStatement = HavingClause | HavingGroup
 export type SQLHavingOperator = SQLWhereOperator
 
-export type EscapedValue = string | number | boolean | Date | RawValue | EscapedValue[]
+export type EscapedValue = string | number | boolean | Date | RawValue | EscapedValue[] | Select<any>
 
 export type FieldValue = { field: string, value: EscapedValue }
 export type FieldValueObject = { [field: string]: EscapedValue }
@@ -76,7 +77,9 @@ export function isWhereStatement(something: any): something is WhereStatement {
 }
 
 export function escape(value: EscapedValue): string {
-    if ( value instanceof RawValue ) {
+    if ( value instanceof Select ) {
+        return `(${value.sql(5)})`
+    } else if ( value instanceof RawValue ) {
         return value.value
     } else if ( Array.isArray(value) ) {
         return `(${value.map(escape).join(',')})`