fix(mongo): existence check -> equality check

packages/mongo/src/builder.ts

@@ -24,7 +24,7 @@ function transformFieldQuery(query: Query.FieldQuery, key: string, filters: Filt
   } else if (query instanceof RegExp) {
     return { $regex: query }
   } else if (isNullable(query)) {
-    return { $exists: false }
+    return null
   }
 
   // query operators
@@ -52,7 +52,7 @@ function transformFieldQuery(query: Query.FieldQuery, key: string, filters: Filt
     } else if (prop === '$el') {
       const child = transformFieldQuery(query[prop], key, filters)
       if (child === false) return false
-      if (child !== true) result.$elemMatch = child
+      if (child !== true) result.$elemMatch = child!
     } else if (prop === '$regexFor') {
       filters.push({
         $expr: {
@@ -62,6 +62,9 @@ function transformFieldQuery(query: Query.FieldQuery, key: string, filters: Filt
           },
         },
       })
+    } else if (prop === '$exists') {
+      if (query[prop]) return { $ne: null }
+      else return null
     } else {
       result[prop] = query[prop]
     }

packages/mysql/src/builder.ts

@@ -48,7 +48,6 @@ export class MySQLBuilder extends Builder {
     }
 
     this.transformers['date'] = {
-      encode: value => value,
       decode: value => `cast(${value} as date)`,
       load: value => {
         if (isNullable(value) || typeof value === 'object') return value
@@ -67,14 +66,12 @@ export class MySQLBuilder extends Builder {
     }
 
     this.transformers['time'] = {
-      encode: value => value,
       decode: value => `cast(${value} as time)`,
       load: value => this.driver.types['time'].load(value),
       dump: value => isNullable(value) ? value : Time.template('yyyy-MM-dd hh:mm:ss.SSS', value),
     }
 
     this.transformers['timestamp'] = {
-      encode: value => value,
       decode: value => `cast(${value} as datetime)`,
       load: value => {
         if (isNullable(value) || typeof value === 'object') return value

packages/postgres/src/builder.ts

@@ -91,17 +91,12 @@ export class PostgresBuilder extends Builder {
     }
 
     this.transformers['boolean'] = {
-      encode: value => value,
       decode: value => `(${value})::boolean`,
-      load: value => value,
-      dump: value => value,
     }
 
     this.transformers['decimal'] = {
-      encode: value => value,
       decode: value => `(${value})::double precision`,
       load: value => isNullable(value) ? value : +value,
-      dump: value => value,
     }
 
     this.transformers['binary'] = {
@@ -112,7 +107,6 @@ export class PostgresBuilder extends Builder {
     }
 
     this.transformers['date'] = {
-      encode: value => value,
       decode: value => `cast(${value} as date)`,
       load: value => {
         if (isNullable(value) || typeof value === 'object') return value
@@ -125,15 +119,13 @@ export class PostgresBuilder extends Builder {
     }
 
     this.transformers['time'] = {
-      encode: value => value,
       decode: value => `cast(${value} as time)`,
       load: value => this.driver.types['time'].load(value),
       dump: value => this.driver.types['time'].dump(value),
     }
 
     this.transformers['timestamp'] = {
-      encode: value => value,
-      decode: value => `cast(${value} as datetime)`,
+      decode: value => `cast(${value} as timestamp)`,
       load: value => {
         if (isNullable(value) || typeof value === 'object') return value
         return new Date(value)

packages/sql-utils/src/index.ts

@@ -24,10 +24,10 @@ export type EvalOperators = {
 } & { $: (expr: any) => string }
 
 interface Transformer<S=any, T=any> {
-  encode(value: string): string
-  decode(value: string): string
-  load(value: S): T
-  dump(value: T): S
+  encode?(value: string): string
+  decode?(value: string): string
+  load?(value: S | null): T | null
+  dump?(value: T | null): S | null
 }
 
 interface State {
@@ -312,7 +312,7 @@ export class Builder {
   protected transform(value: string, type: Type | Eval.Expr | undefined, method: 'encode' | 'decode' | 'load' | 'dump', miss?: any) {
     type = Type.isType(type) ? type : Type.fromTerm(type)
     const transformer = this.transformers[type.type] ?? this.transformers[this.driver.database.types[type.type]?.type!]
-    return transformer ? transformer[method](value) : (miss ?? value)
+    return transformer?.[method] ? transformer[method](value) : (miss ?? value)
   }
 
   protected groupObject(_fields: any) {

packages/tests/src/model.ts

@@ -1,4 +1,4 @@
-import { valueMap, isNullable } from 'cosmokit'
+import { valueMap, isNullable, deduplicate } from 'cosmokit'
 import { $, Database, Field, Type, unravel } from 'minato'
 import { expect } from 'chai'
 
@@ -264,7 +264,7 @@ function ModelOperations(database: Database<Tables, Types>) {
 function getValue(obj: any, path: string) {
   if (path.includes('.')) {
     const index = path.indexOf('.')
-    return getValue(obj[path.slice(0, index)] ??= {}, path.slice(index + 1))
+    return getValue(obj[path.slice(0, index)] ?? {}, path.slice(index + 1))
   } else {
     return obj[path]
   }
@@ -566,7 +566,11 @@ namespace ModelOperations {
 
     it('project with dot notation', async () => {
       const table = await setup(database, 'dobjects', dobjectTable)
-      const keys = Object.keys(database.tables['dobjects'].fields).flatMap(k => k.split('.').reduce((arr, c) => arr.length ? [`${arr[0]}.${c}`, ...arr] : [c], []))
+      const keys = deduplicate([
+        'foo.nested.object',
+        'foo.nested.object.embed',
+        ...Object.keys(database.tables['dobjects'].fields).flatMap(k => k.split('.').reduce((arr, c) => arr.length ? [`${arr[0]}.${c}`, ...arr] : [c], [])),
+      ])
       await Promise.all(keys.map(key =>
         expect(database.select('dobjects').project([key as any]).execute()).to.eventually.have.deep.members(table.map(row => unravel({ [key]: getValue(row, key) })))
       ))

packages/tests/src/update.ts

@@ -188,6 +188,7 @@ namespace OrmOperations {
       data.text = null as never
       await database.set('temp2', { timestamp: { $exists: true } }, { text: null })
       await expect(database.get('temp2', {})).to.eventually.have.shape(table)
+      await expect(database.get('temp2', { text: { $exists: false } })).to.eventually.have.length(1)
     })
 
     it('noop', async () => {