From 5cdf1cc00dc201c07e6f343cf1fdea2fd23a43fb Mon Sep 17 00:00:00 2001
From: what <what-00@qq.com>
Date: Thu, 20 Aug 2026 15:58:03 +0800
Subject: [PATCH] =?UTF-8?q?=E9=87=8D=E6=9E=84:=20=E8=99=9A=E6=8B=9F?=
 =?UTF-8?q?=E8=B5=84=E6=BA=90=E6=94=B9=E7=94=A8=20NewVirtualResource=20?=
 =?UTF-8?q?=E6=98=BE=E5=BC=8F=E6=9E=84=E9=80=A0=EF=BC=8C=E7=A7=BB=E9=99=A4?=
 =?UTF-8?q?=20WithVirtual?=
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WithVirtual(bool) 只是给 New() 打一个标记位，虚拟资源需要的表达式（子查询）没有
承载的地方，之前借用 table string 字段硬拼字符串。改成 NewVirtualResource(res,
code, table, opts...) 专门构造：table 参数直接接收 exp.SQLExpression，
GetTableExpr 对虚拟资源直接用它生成子查询表达式，不用再手工拼括号和字符串；
container/conn/historyRoles 从传入的父资源上直接复用。

GetTableExpr 返回值类型从 exp.LiteralExpression 放宽成 exp.Aliaseable，
兼容 db.T(...)（IdentifierExpression）和 db.L(...)（LiteralExpression）两种
返回值。
---
 resource.go                  |  2 +-
 resx/res_interceptor_test.go |  9 ++++-----
 resx/resource.go             | 17 ++++++++---------
 resx/virtual_resource.go     | 33 +++++++++++++++++++++++++++++++++
 4 files changed, 46 insertions(+), 15 deletions(-)
 create mode 100644 resx/virtual_resource.go

diff --git a/resource.go b/resource.go
index 349e023..d927c81 100755
--- a/resource.go
+++ b/resource.go
@@ -64,7 +64,7 @@ type Resource interface {
 	// GetTable 原始表名
 	GetTable() string
 	// GetTableExpr 可用于 FROM/JOIN 的表引用表达式
-	GetTableExpr() exp.LiteralExpression
+	GetTableExpr() exp.Aliaseable
 
 	DB() *db.Database
 	BeginTransaction() (*db.TxDatabase, error)
diff --git a/resx/res_interceptor_test.go b/resx/res_interceptor_test.go
index 57d9d1c..cd6cd3b 100644
--- a/resx/res_interceptor_test.go
+++ b/resx/res_interceptor_test.go
@@ -565,14 +565,13 @@ func (t *hooksTest) TestVirtualResource_SkipsRolesConditionAndOnAfter() {
 		}, nil
 	})
 
-	res := resx.New(app, "User", "users",
-		resx.WithConn("default"),
-		resx.WithVirtual(true),
+	baseRes := resx.New(app, "User", "users", resx.WithConn("default"))
+	res := resx.NewVirtualResource(baseRes, "User", db.From(db.T("users")),
 		resx.WithFields(resx.NewResField("name", "User", resx.FieldWithName("姓名"), resx.FieldWithDataType(req.ResString))),
 	)
 
-	// 实际生成的 SQL（虚拟资源用字面量拼表名，且没有 owned_user 权限条件）：
-	// UPDATE (users) AS `User` SET `name`='新名字' WHERE (`id` = 1)
+	// 实际生成的 SQL（虚拟资源拿子查询拼表名，且没有 owned_user 权限条件）：
+	// UPDATE (SELECT * FROM `users`) AS `User` SET `name`='新名字' WHERE (`id` = 1)
 	sql, _, _ := res.GetDBTable(base.GetAnonymous()).Update().
 		Set(db.Record{"name": "新名字"}).
 		Where(db.C("id").Eq(1)).
diff --git a/resx/resource.go b/resx/resource.go
index f269e8c..7566351 100644
--- a/resx/resource.go
+++ b/resx/resource.go
@@ -95,6 +95,10 @@ type resource struct {
 	conn         string
 	isResVirtual bool
 	table        string
+	// virtualTable 只有虚拟资源（NewVirtualResource 构造的）才会设置，table 留空。GetTableExpr
+	// 用它代替 table 拼子查询：db.V(sd.Expression()) 让方言自己生成/加括号，不用手写 "(" + sql + ")"
+	// 拼字符串。
+	virtualTable exp.SQLExpression
 	primarykey   string
 	historyRoles []string
 	fields       []req.ResField
@@ -150,11 +154,6 @@ func WithConn(v string) Option {
 	return func(r *resource) { r.conn = v }
 }
 
-// WithVirtual 标记为虚拟资源
-func WithVirtual(v bool) Option {
-	return func(r *resource) { r.isResVirtual = v }
-}
-
 // WithPrimarykey 设置主键字段名，不设置则默认为 "id"
 func WithPrimarykey(v string) Option {
 	return func(r *resource) { r.primarykey = v }
@@ -290,17 +289,17 @@ func (this *resource) autoCreateTable(conn *db.Database) error {
 	})
 }
 
-// GetTable 原始表名
+// GetTable 原始表名；虚拟资源没有物理表名，返回空字符串
 func (this *resource) GetTable() string {
 	return this.table
 }
 
 // GetTableExpr 获取资源对应的可用于 FROM/JOIN 的表引用表达式
-func (this *resource) GetTableExpr() exp.LiteralExpression {
+func (this *resource) GetTableExpr() exp.Aliaseable {
 	if this.isResVirtual {
-		return db.L("(" + this.table + ")")
+		return db.L("?", this.virtualTable.Clone())
 	}
-	return db.V(db.T(this.table))
+	return db.T(this.table)
 }
 
 // GetDBTable 获取资源对应的数据库连接
diff --git a/resx/virtual_resource.go b/resx/virtual_resource.go
new file mode 100644
index 0000000..6a7fff3
--- /dev/null
+++ b/resx/virtual_resource.go
@@ -0,0 +1,33 @@
+package resx
+
+import (
+	"sync"
+
+	"git.fsdpf.net/go/db/exp"
+	"git.fsdpf.net/go/req"
+)
+
+func NewVirtualResource(res req.Resource, code string, table exp.SQLExpression, opts ...Option) req.Resource {
+	pRes, ok := res.(*resource)
+	if !ok {
+		panic("resx.NewVirtualResource: res 必须是 resx.New 构造出来的 req.Resource")
+	}
+
+	r := &resource{
+		container:    pRes.container,
+		conn:         pRes.conn,
+		historyRoles: pRes.historyRoles,
+		initOnce:     &sync.Once{},
+		uuid:         code,
+		code:         code,
+		name:         code,
+		table:        code,
+		isResVirtual: true,
+		virtualTable: table,
+		primarykey:   "id",
+	}
+	for _, opt := range opts {
+		opt(r)
+	}
+	return r
+}