Support delete with no bean (#1926)

Now you can use delete like this:

```
orm.Table("my_table").Where("id=?",1).Delete()
```

Reviewed-on: https://gitea.com/xorm/xorm/pulls/1926
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-committed-by: Lunny Xiao <xiaolunwen@gmail.com>

README.md

@@ -245,35 +245,38 @@ for rows.Next() {
 
 ```Go
 affected, err := engine.ID(1).Update(&user)
-// UPDATE user SET ... Where id = ?
+// UPDATE user SET ... WHERE id = ?
 
 affected, err := engine.Update(&user, &User{Name:name})
-// UPDATE user SET ... Where name = ?
+// UPDATE user SET ... WHERE name = ?
 
 var ids = []int64{1, 2, 3}
 affected, err := engine.In("id", ids).Update(&user)
-// UPDATE user SET ... Where id IN (?, ?, ?)
+// UPDATE user SET ... WHERE id IN (?, ?, ?)
 
 // force update indicated columns by Cols
 affected, err := engine.ID(1).Cols("age").Update(&User{Name:name, Age: 12})
-// UPDATE user SET age = ?, updated=? Where id = ?
+// UPDATE user SET age = ?, updated=? WHERE id = ?
 
 // force NOT update indicated columns by Omit
 affected, err := engine.ID(1).Omit("name").Update(&User{Name:name, Age: 12})
-// UPDATE user SET age = ?, updated=? Where id = ?
+// UPDATE user SET age = ?, updated=? WHERE id = ?
 
 affected, err := engine.ID(1).AllCols().Update(&user)
-// UPDATE user SET name=?,age=?,salt=?,passwd=?,updated=? Where id = ?
+// UPDATE user SET name=?,age=?,salt=?,passwd=?,updated=? WHERE id = ?
 ```
 
 * `Delete` delete one or more records, Delete MUST have condition
 
 ```Go
 affected, err := engine.Where(...).Delete(&user)
-// DELETE FROM user Where ...
+// DELETE FROM user WHERE ...
 
 affected, err := engine.ID(2).Delete(&user)
-// DELETE FROM user Where id = ?
+// DELETE FROM user WHERE id = ?
+
+affected, err := engine.Table("user").Where(...).Delete()
+// DELETE FROM user WHERE ...
 ```
 
 * `Count` count records

README_CN.md

@@ -271,6 +271,9 @@ affected, err := engine.Where(...).Delete(&user)
 
 affected, err := engine.ID(2).Delete(&user)
 // DELETE FROM user Where id = ?
+
+affected, err := engine.Table("user").Where(...).Delete()
+// DELETE FROM user WHERE ...
 ```
 
 * `Count` 获取记录条数

engine.go

@@ -1202,10 +1202,10 @@ func (engine *Engine) Update(bean interface{}, condiBeans ...interface{}) (int64
 }
 
 // Delete records, bean's non-empty fields are conditions
-func (engine *Engine) Delete(bean interface{}) (int64, error) {
+func (engine *Engine) Delete(beans ...interface{}) (int64, error) {
 	session := engine.NewSession()
 	defer session.Close()
-	return session.Delete(bean)
+	return session.Delete(beans...)
 }
 
 // Get retrieve one record from table, bean's non-empty fields

integrations/session_delete_test.go

@@ -241,3 +241,28 @@ func TestUnscopeDelete(t *testing.T) {
 	assert.NoError(t, err)
 	assert.False(t, has)
 }
+
+func TestDelete2(t *testing.T) {
+	assert.NoError(t, PrepareEngine())
+
+	type UserinfoDelete2 struct {
+		Uid   int64 `xorm:"id pk not null autoincr"`
+		IsMan bool
+	}
+
+	assert.NoError(t, testEngine.Sync2(new(UserinfoDelete2)))
+
+	user := UserinfoDelete2{}
+	cnt, err := testEngine.Insert(&user)
+	assert.NoError(t, err)
+	assert.EqualValues(t, 1, cnt)
+
+	cnt, err = testEngine.Table("userinfo_delete2").In("id", []int{1}).Delete()
+	assert.NoError(t, err)
+	assert.EqualValues(t, 1, cnt)
+
+	user2 := UserinfoDelete2{}
+	has, err := testEngine.ID(1).Get(&user2)
+	assert.NoError(t, err)
+	assert.False(t, has)
+}

interface.go

@@ -30,7 +30,7 @@ type Interface interface {
 	CreateUniques(bean interface{}) error
 	Decr(column string, arg ...interface{}) *Session
 	Desc(...string) *Session
-	Delete(interface{}) (int64, error)
+	Delete(...interface{}) (int64, error)
 	Distinct(columns ...string) *Session
 	DropIndexes(bean interface{}) error
 	Exec(sqlOrArgs ...interface{}) (sql.Result, error)

session_delete.go

@@ -83,7 +83,7 @@ func (session *Session) cacheDelete(table *schemas.Table, tableName, sqlStr stri
 }
 
 // Delete records, bean's non-empty fields are conditions
-func (session *Session) Delete(bean interface{}) (int64, error) {
+func (session *Session) Delete(beans ...interface{}) (int64, error) {
 	if session.isAutoClose {
 		defer session.Close()
 	}
@@ -92,20 +92,32 @@ func (session *Session) Delete(bean interface{}) (int64, error) {
 		return 0, session.statement.LastError
 	}
 
-	if err := session.statement.SetRefBean(bean); err != nil {
+	var (
-		return 0, err
+		condSQL  string
+		condArgs []interface{}
+		err      error
+		bean     interface{}
+	)
+	if len(beans) > 0 {
+		bean = beans[0]
+		if err = session.statement.SetRefBean(bean); err != nil {
+			return 0, err
+		}
+
+		executeBeforeClosures(session, bean)
+
+		if processor, ok := interface{}(bean).(BeforeDeleteProcessor); ok {
+			processor.BeforeDelete()
+		}
+
+		condSQL, condArgs, err = session.statement.GenConds(bean)
+	} else {
+		condSQL, condArgs, err = session.statement.GenCondSQL(session.statement.Conds())
 	}
-
-	executeBeforeClosures(session, bean)
-
-	if processor, ok := interface{}(bean).(BeforeDeleteProcessor); ok {
-		processor.BeforeDelete()
-	}
-
-	condSQL, condArgs, err := session.statement.GenConds(bean)
 	if err != nil {
 		return 0, err
 	}
+
 	pLimitN := session.statement.LimitN
 	if len(condSQL) == 0 && (pLimitN == nil || *pLimitN == 0) {
 		return 0, ErrNeedDeletedCond
@@ -156,7 +168,7 @@ func (session *Session) Delete(bean interface{}) (int64, error) {
 
 	var realSQL string
 	argsForCache := make([]interface{}, 0, len(condArgs)*2)
-	if session.statement.GetUnscoped() || table.DeletedColumn() == nil { // tag "deleted" is disabled
+	if session.statement.GetUnscoped() || table == nil || table.DeletedColumn() == nil { // tag "deleted" is disabled
 		realSQL = deleteSQL
 		copy(argsForCache, condArgs)
 		argsForCache = append(condArgs, argsForCache...)
@@ -220,27 +232,29 @@ func (session *Session) Delete(bean interface{}) (int64, error) {
 		return 0, err
 	}
 
-	// handle after delete processors
+	if bean != nil {
-	if session.isAutoCommit {
+		// handle after delete processors
-		for _, closure := range session.afterClosures {
+		if session.isAutoCommit {
-			closure(bean)
+			for _, closure := range session.afterClosures {
-		}
+				closure(bean)
-		if processor, ok := interface{}(bean).(AfterDeleteProcessor); ok {
+			}
-			processor.AfterDelete()
+			if processor, ok := interface{}(bean).(AfterDeleteProcessor); ok {
-		}
+				processor.AfterDelete()
-	} else {
-		lenAfterClosures := len(session.afterClosures)
-		if lenAfterClosures > 0 {
-			if value, has := session.afterDeleteBeans[bean]; has && value != nil {
-				*value = append(*value, session.afterClosures...)
-			} else {
-				afterClosures := make([]func(interface{}), lenAfterClosures)
-				copy(afterClosures, session.afterClosures)
-				session.afterDeleteBeans[bean] = &afterClosures
 			}
 		} else {
-			if _, ok := interface{}(bean).(AfterDeleteProcessor); ok {
+			lenAfterClosures := len(session.afterClosures)
-				session.afterDeleteBeans[bean] = nil
+			if lenAfterClosures > 0 && len(beans) > 0 {
+				if value, has := session.afterDeleteBeans[beans[0]]; has && value != nil {
+					*value = append(*value, session.afterClosures...)
+				} else {
+					afterClosures := make([]func(interface{}), lenAfterClosures)
+					copy(afterClosures, session.afterClosures)
+					session.afterDeleteBeans[bean] = &afterClosures
+				}
+			} else {
+				if _, ok := interface{}(bean).(AfterDeleteProcessor); ok {
+					session.afterDeleteBeans[bean] = nil
+				}
 			}
 		}
 	}