feat: optimize alias

BigeYoung · Apr 6, 2022 · 068730b · 068730b
1 parent e3eb97b
commit 068730b
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Showing 6 changed files with 29 additions and 30 deletions.
diff --git a/README.ZH_CN.md b/README.ZH_CN.md
@@ -718,9 +718,10 @@ users, err := u.WithContext(ctx).Distinct(u.Name, u.Age).Order(u.Name, u.Age.Des
 联表查询方法，`Join` 方法对应 `inner join`，此外还有 `LeftJoin` 方法和 `RightJoin` 方法。
 
 ```go
-u := query.Use(db).User
-e := query.Use(db).Email
-c := query.Use(db).CreditCard
+q := query.Use(db)
+u := q.User
+e := q.Email
+c := q.CreditCard
 
 type Result struct {
     Name  string
@@ -734,14 +735,14 @@ err := u.WithContext(ctx).Select(u.Name, e.Email).LeftJoin(e, e.UserID.EqCol(u.I
 
 // self join
 var result Result
-u2 := query.Use(db).User.As("u2")
-err := u.WithContext(ctx).Select(u.Name, u.ID).LeftJoin(u2, u2.ID.EqCol(u.ID)).Scan(&result)
+u2 := u.As("u2")
+err := u.WithContext(ctx).Select(u.Name, u2.ID).LeftJoin(u2, u2.ID.EqCol(u.ID)).Scan(&result)
 // SELECT users.name, u2.id FROM `users` left join `users` u2 on u2.id = users.id
 
 //join with sub query
 var result Result
 e2 := e.As("e2")
-err := u.WithContext(ctx).Select(u.Name, e2.Email).LeftJoin(e.Select(e.Email, e.UserID).Where(e.UserID.Gt(100)).As("e2"), e2.UserID.EqCol(u.ID)).Scan(&result)
+err := u.WithContext(ctx).Select(u.Name, e2.Email).LeftJoin(e.WithContext(ctx).Select(e.Email, e.UserID).Where(e.UserID.Gt(100)).As("e2"), e2.UserID.EqCol(u.ID)).Scan(&result)
 // SELECT users.name, e2.email FROM `users` left join (select email,user_id from emails  where user_id > 100) as e2 on e2.user_id = users.id
 
 rows, err := u.WithContext(ctx).Select(u.Name, e.Email).LeftJoin(e, e.UserID.EqCol(u.ID)).Rows()

diff --git a/README.md b/README.md
@@ -739,14 +739,14 @@ err := u.WithContext(ctx).Select(u.Name, e.Email).LeftJoin(e, e.UserID.EqCol(u.I
 
 // self join
 var result Result
-u2 := query.Use(db).User.As("u2")
-err := u.WithContext(ctx).Select(u.Name, u.ID).LeftJoin(u2, u2.ID.EqCol(u.ID)).Scan(&result)
+u2 := u.As("u2")
+err := u.WithContext(ctx).Select(u.Name, u2.ID).LeftJoin(u2, u2.ID.EqCol(u.ID)).Scan(&result)
 // SELECT users.name, u2.id FROM `users` left join `users` u2 on u2.id = users.id
 
 //join with sub query
 var result Result
 e2 := e.As("e2")
-err := u.WithContext(ctx).Select(u.Name, e2.Email).LeftJoin(e.Select(e.Email, e.UserID).Where(e.UserID.Gt(100)).As("e2"), e2.UserID.EqCol(u.ID)).Scan(&result)
+err := u.WithContext(ctx).Select(u.Name, e2.Email).LeftJoin(e.WithContext(ctx).Select(e.Email, e.UserID).Where(e.UserID.Gt(100)).As("e2"), e2.UserID.EqCol(u.ID)).Scan(&result)
 // SELECT users.name, e2.email FROM `users` left join (select email,user_id from emails  where user_id > 100) as e2 on e2.user_id = users.id
 
 rows, err := u.WithContext(ctx).Select(u.Name, e.Email).LeftJoin(e, e.UserID.EqCol(u.ID)).Rows()

diff --git a/do.go b/do.go
@@ -7,13 +7,13 @@ import (
 	"reflect"
 	"strings"
 
-	"gorm.io/gen/helper"
 	"gorm.io/gorm"
 	"gorm.io/gorm/callbacks"
 	"gorm.io/gorm/clause"
 	"gorm.io/gorm/schema"
 
 	"gorm.io/gen/field"
+	"gorm.io/gen/helper"
 )
 
 var (
@@ -173,7 +173,8 @@ func (d DO) As(alias string) Dao {
 	return &d
 }
 
-func (d DO) Alias() string {
+// Alias return alias name
+func (d *DO) Alias() string {
 	return d.alias
 }
 
@@ -321,17 +322,19 @@ func (d *DO) join(table schema.Tabler, joinType clause.JoinType, conds []field.E
 	if len(conds) == 0 {
 		return d.withError(ErrEmptyCondition)
 	}
+
 	join := clause.Join{
 		Type:  joinType,
 		Table: clause.Table{Name: table.TableName()},
 		ON:    clause.Where{Exprs: toExpression(conds...)},
 	}
 	if do, ok := table.(Dao); ok {
-		join.Expression = helper.NewJoinExpr(join, Table(do).underlyingDB().Statement.TableExpr)
+		join.Expression = helper.NewJoinTblExpr(join, Table(do).underlyingDB().Statement.TableExpr)
 	}
-	if al, ok := table.(Alias); ok {
+	if al, ok := table.(interface{ Alias() string }); ok {
 		join.Table.Alias = al.Alias()
 	}
+
 	from := getFromClause(d.db)
 	from.Joins = append(from.Joins, join)
 	return d.getInstance(d.db.Clauses(from))

diff --git a/helper/clause.go b/helper/clause.go
@@ -124,16 +124,17 @@ func JoinSetBuilder(src *strings.Builder, setValue strings.Builder) {
 	}
 }
 
-// Join join clause for from
-type JoinExpr struct {
+// JoinTblExpr join clause with table expression(sub query...)
+type JoinTblExpr struct {
 	clause.Join
 	TableExpr clause.Expression
 }
 
-func NewJoinExpr(join clause.Join, tbExpr clause.Expression) JoinExpr {
-	return JoinExpr{Join: join, TableExpr: tbExpr}
+func NewJoinTblExpr(join clause.Join, tbExpr clause.Expression) JoinTblExpr {
+	return JoinTblExpr{Join: join, TableExpr: tbExpr}
 }
-func (join JoinExpr) Build(builder clause.Builder) {
+
+func (join JoinTblExpr) Build(builder clause.Builder) {
 	if builder == nil {
 		return
 	}
@@ -145,6 +146,7 @@ func (join JoinExpr) Build(builder clause.Builder) {
 	if join.TableExpr != nil {
 		join.TableExpr.Build(builder)
 	}
+
 	if len(join.ON.Exprs) > 0 {
 		_, _ = builder.WriteString(" ON ")
 		join.ON.Build(builder)

diff --git a/interface.go b/interface.go
@@ -31,15 +31,11 @@ type subQuery interface {
 
 	Condition
 }
-type Alias interface {
-	Alias() string
-}
 
 // Dao CRUD methods
 type Dao interface {
 	subQuery
 	schema.Tabler
-	Alias
 	As(alias string) Dao
 
 	Not(conds ...Condition) Dao

diff --git a/internal/template/struct.go b/internal/template/struct.go
@@ -13,11 +13,13 @@ const (
 		{{.NewStructName}}Do {{.NewStructName}}Do
 		` + fields + `
 	}
-	` + tableMethod + asMethond + aliasMethod + updateFieldMethod + `
+	` + tableMethod + asMethond + updateFieldMethod + `
 	
-	func ({{.S}} *{{.NewStructName}}) WithContext(ctx context.Context) *{{.NewStructName}}Do { return {{.S}}.{{.NewStructName}}Do.WithContext(ctx)}
+	func ({{.S}} *{{.NewStructName}}) WithContext(ctx context.Context) *{{.NewStructName}}Do { return {{.S}}.{{.NewStructName}}Do.WithContext(ctx) }
 
-	func ({{.S}} {{.NewStructName}}) TableName() string { return {{.S}}.{{.NewStructName}}Do.TableName()} 
+	func ({{.S}} {{.NewStructName}}) TableName() string { return {{.S}}.{{.NewStructName}}Do.TableName() } 
+
+	func ({{.S}} {{.NewStructName}}) Alias() string { return {{.S}}.{{.NewStructName}}Do.Alias() }
 
 	` + getFieldMethod + fillFieldMapMethod + cloneMethod + relationship + defineMethodStruct
 )
@@ -73,11 +75,6 @@ func ({{.S}} {{.NewStructName}}) As(alias string) *{{.NewStructName}} {
 	{{.S}}.{{.NewStructName}}Do.DO = *({{.S}}.{{.NewStructName}}Do.As(alias).(*gen.DO))
 	return {{.S}}.updateTableName(alias)
 }
-`
-	aliasMethod = `	
-func ({{.S}} {{.NewStructName}}) Alias() string { 
-	return {{.S}}.{{.NewStructName}}Do.Alias()
-}
 `
 	updateFieldMethod = `
 func ({{.S}} *{{.NewStructName}}) updateTableName(table string) *{{.NewStructName}} {