diff --git a/pkg/db/delete_builder.go b/pkg/db/delete_builder.go
index 881dd8e..769d01b 100644
--- a/pkg/db/delete_builder.go
+++ b/pkg/db/delete_builder.go
@@ -1,18 +1,110 @@
 package db
 
-import "gorm.io/gorm"
+import (
+	"gorm.io/gorm"
+)
 
 type DeleteBuilder[T any] struct {
-	Expr
-	db *gorm.DB
+	db   *gorm.DB
+	expr *Expr
 }
 
 func NewDeleteBuilder[T any](db *gorm.DB) *DeleteBuilder[T] {
-	return &DeleteBuilder[T]{Expr{}, db}
+	return &DeleteBuilder[T]{db: db, expr: &Expr{}}
 }
 
-func (b *DeleteBuilder[T]) Commit() (int64, error) {
+func (d *DeleteBuilder[T]) Eq(col string, val any) *DeleteBuilder[T] {
+	d.expr.Eq(col, val)
+	return d
+}
+
+func (d *DeleteBuilder[T]) Neq(col string, val any) *DeleteBuilder[T] {
+	d.expr.Neq(col, val)
+	return d
+}
+
+func (d *DeleteBuilder[T]) Lt(col string, val any) *DeleteBuilder[T] {
+	d.expr.Lt(col, val)
+	return d
+}
+
+func (d *DeleteBuilder[T]) Lte(col string, val any) *DeleteBuilder[T] {
+	d.expr.Lte(col, val)
+	return d
+}
+
+func (d *DeleteBuilder[T]) Gt(col string, val any) *DeleteBuilder[T] {
+	d.expr.Gt(col, val)
+	return d
+}
+
+func (d *DeleteBuilder[T]) Gte(col string, val any) *DeleteBuilder[T] {
+	d.expr.Gte(col, val)
+	return d
+}
+
+func (d *DeleteBuilder[T]) Between(col string, less, more any) *DeleteBuilder[T] {
+	d.expr.Between(col, less, more)
+	return d
+}
+
+func (d *DeleteBuilder[T]) NotBetween(col string, less, more any) *DeleteBuilder[T] {
+	d.expr.NotBetween(col, less, more)
+	return d
+}
+
+func (d *DeleteBuilder[T]) IsNull(col string) *DeleteBuilder[T] {
+	d.expr.IsNull(col)
+	return d
+}
+
+func (d *DeleteBuilder[T]) NotNull(col string) *DeleteBuilder[T] {
+	d.expr.NotNull(col)
+	return d
+}
+
+func (d *DeleteBuilder[T]) Like(col, tpl string) *DeleteBuilder[T] {
+	d.expr.Like(col, tpl)
+	return d
+}
+
+func (d *DeleteBuilder[T]) NotLike(col, tpl string) *DeleteBuilder[T] {
+	d.expr.NotLike(col, tpl)
+	return d
+}
+
+func (d *DeleteBuilder[T]) In(col string, values ...any) *DeleteBuilder[T] {
+	d.expr.In(col, values...)
+	return d
+}
+
+func (d *DeleteBuilder[T]) NotIn(col string, values ...any) *DeleteBuilder[T] {
+	d.expr.NotIn(col, values...)
+	return d
+}
+
+func (d *DeleteBuilder[T]) When(condition bool, then func(ex *Expr), elses ...func(ex *Expr)) *DeleteBuilder[T] {
+	d.expr.When(condition, then, elses...)
+	return d
+}
+
+func (d *DeleteBuilder[T]) Or(or func(ex *Expr)) *DeleteBuilder[T] {
+	d.expr.Or(or)
+	return d
+}
+
+func (d *DeleteBuilder[T]) And(and func(ex *Expr)) *DeleteBuilder[T] {
+	d.expr.And(and)
+	return d
+}
+
+func (d *DeleteBuilder[T]) Not(not func(ex *Expr)) *DeleteBuilder[T] {
+	d.expr.Not(not)
+	return d
+}
+
+func (d *DeleteBuilder[T]) Commit() (int64, error) {
 	var t T
-	res := b.db.Scopes(b.Scopes).Delete(&t)
+	res := d.db.Scopes(d.expr.Scopes).Delete(&t)
 	return res.RowsAffected, res.Error
 }
diff --git a/pkg/db/expr.go b/pkg/db/expr.go
index c886bf8..a37c057 100644
--- a/pkg/db/expr.go
+++ b/pkg/db/expr.go
@@ -9,6 +9,10 @@ type Expr struct {
 	clauses []clause.Expression
 }
 
+func NewExpr() *Expr {
+	return &Expr{}
+}
+
 func (e *Expr) add(expr clause.Expression) *Expr {
 	e.clauses = append(e.clauses, expr)
 	return e
diff --git a/pkg/db/query_builder.go b/pkg/db/query_builder.go
index 4f29a3a..0bb2bcb 100644
--- a/pkg/db/query_builder.go
+++ b/pkg/db/query_builder.go
@@ -9,10 +9,10 @@ import (
 // QueryBuilder 查询构造器
 // TODO（hupeh）：实现 joins 和表别名
 type QueryBuilder[T any] struct {
-	Expr
 	db       *gorm.DB
 	selects  []string
 	omits    []string
+	expr     *Expr
 	orders   []string
 	limit    int
 	offset   int
@@ -21,7 +21,7 @@ type QueryBuilder[T any] struct {
 }
 
 func NewQueryBuilder[T any](db *gorm.DB) *QueryBuilder[T] {
-	return &QueryBuilder[T]{Expr: Expr{}, db: db}
+	return &QueryBuilder[T]{expr: &Expr{}, db: db}
 }
 
 type preload struct {
@@ -46,6 +46,96 @@ func (q *QueryBuilder[T]) Omit(columns ...string) *QueryBuilder[T] {
 	return q
 }
 
+func (q *QueryBuilder[T]) Eq(col string, val any) *QueryBuilder[T] {
+	q.expr.Eq(col, val)
+	return q
+}
+
+func (q *QueryBuilder[T]) Neq(col string, val any) *QueryBuilder[T] {
+	q.expr.Neq(col, val)
+	return q
+}
+
+func (q *QueryBuilder[T]) Lt(col string, val any) *QueryBuilder[T] {
+	q.expr.Lt(col, val)
+	return q
+}
+
+func (q *QueryBuilder[T]) Lte(col string, val any) *QueryBuilder[T] {
+	q.expr.Lte(col, val)
+	return q
+}
+
+func (q *QueryBuilder[T]) Gt(col string, val any) *QueryBuilder[T] {
+	q.expr.Gt(col, val)
+	return q
+}
+
+func (q *QueryBuilder[T]) Gte(col string, val any) *QueryBuilder[T] {
+	q.expr.Gte(col, val)
+	return q
+}
+
+func (q *QueryBuilder[T]) Between(col string, less, more any) *QueryBuilder[T] {
+	q.expr.Between(col, less, more)
+	return q
+}
+
+func (q *QueryBuilder[T]) NotBetween(col string, less, more any) *QueryBuilder[T] {
+	q.expr.NotBetween(col, less, more)
+	return q
+}
+
+func (q *QueryBuilder[T]) IsNull(col string) *QueryBuilder[T] {
+	q.expr.IsNull(col)
+	return q
+}
+
+func (q *QueryBuilder[T]) NotNull(col string) *QueryBuilder[T] {
+	q.expr.NotNull(col)
+	return q
+}
+
+func (q *QueryBuilder[T]) Like(col, tpl string) *QueryBuilder[T] {
+	q.expr.Like(col, tpl)
+	return q
+}
+
+func (q *QueryBuilder[T]) NotLike(col, tpl string) *QueryBuilder[T] {
+	q.expr.NotLike(col, tpl)
+	return q
+}
+
+func (q *QueryBuilder[T]) In(col string, values ...any) *QueryBuilder[T] {
+	q.expr.In(col, values...)
+	return q
+}
+
+func (q *QueryBuilder[T]) NotIn(col string, values ...any) *QueryBuilder[T] {
+	q.expr.NotIn(col, values...)
+	return q
+}
+
+func (q *QueryBuilder[T]) When(condition bool, then func(ex *Expr), elses ...func(ex *Expr)) *QueryBuilder[T] {
+	q.expr.When(condition, then, elses...)
+	return q
+}
+
+func (q *QueryBuilder[T]) Or(or func(ex *Expr)) *QueryBuilder[T] {
+	q.expr.Or(or)
+	return q
+}
+
+func (q *QueryBuilder[T]) And(and func(ex *Expr)) *QueryBuilder[T] {
+	q.expr.And(and)
+	return q
+}
+
+func (q *QueryBuilder[T]) Not(not func(ex *Expr)) *QueryBuilder[T] {
+	q.expr.Not(not)
+	return q
+}
+
 func (q *QueryBuilder[T]) DescentBy(columns ...string) *QueryBuilder[T] {
 	for _, col := range columns {
 		q.orders = append(q.orders, col+" DESC")
@@ -113,7 +203,7 @@ func (q *QueryBuilder[T]) scopesWithoutEffect(tx *gorm.DB) *gorm.DB {
 	if len(q.distinct) > 0 {
 		tx = tx.Distinct(q.distinct...)
 	}
-	return q.Expr.Scopes(tx)
+	return q.expr.Scopes(tx)
 }
 
 func (q *QueryBuilder[T]) Count() (int64, error) {
diff --git a/pkg/db/repository.go b/pkg/db/repository.go
index bff39f1..0c92bc7 100644
--- a/pkg/db/repository.go
+++ b/pkg/db/repository.go
@@ -70,6 +70,20 @@ func (r *Repository[T]) GetByID(ctx context.Context, id any) (*T, error) {
 	return &entity, nil
 }
 
+func (r *Repository[T]) GetBy(ctx context.Context, expr ...*Expr) (*T, error) {
+	var entity T
+	err := r.DB(ctx).Model(&entity).Scopes(func(tx *gorm.DB) *gorm.DB {
+		for _, e := range expr {
+			tx = e.Scopes(tx)
+		}
+		return tx
+	}).First(&entity).Error
+	if err != nil {
+		return nil, err
+	}
+	return &entity, nil
+}
+
 func (r *Repository[T]) Find(ctx context.Context, expr ...*Expr) ([]*T, error) {
 	var entity T
 	var items []*T
@@ -88,7 +102,7 @@ func (r *Repository[T]) Find(ctx context.Context, expr ...*Expr) ([]*T, error) {
 func (r *Repository[T]) Paginate(ctx context.Context, expr ...*Expr) (*Pager[T], error) {
 	qb := NewQueryBuilder[T](r.DB(ctx))
 	for _, e := range expr {
-		qb.Expr = *e
+		qb.expr = e
 	}
 	return qb.Paginate()
 }
diff --git a/pkg/db/update_builder.go b/pkg/db/update_builder.go
index 9d12364..dbb999f 100644
--- a/pkg/db/update_builder.go
+++ b/pkg/db/update_builder.go
@@ -7,55 +7,145 @@ import (
 )
 
 type UpdateBuilder[T any] struct {
-	Expr
 	db         *gorm.DB
 	selects    []string
 	omits      []string
 	onConflict *clause.OnConflict
+	expr       *Expr
 }
 
 func NewUpdateBuilder[T any](db *gorm.DB) *UpdateBuilder[T] {
-	return &UpdateBuilder[T]{Expr: Expr{}, db: db}
+	return &UpdateBuilder[T]{expr: &Expr{}, db: db}
 }
 
-func (b *UpdateBuilder[T]) Select(columns ...string) *UpdateBuilder[T] {
-	b.selects = append(b.selects, columns...)
-	return b
+func (u *UpdateBuilder[T]) Select(columns ...string) *UpdateBuilder[T] {
+	u.selects = append(u.selects, columns...)
+	return u
 }
 
-func (b *UpdateBuilder[T]) Omit(columns ...string) *UpdateBuilder[T] {
-	b.omits = append(b.omits, columns...)
-	return b
+func (u *UpdateBuilder[T]) Omit(columns ...string) *UpdateBuilder[T] {
+	u.omits = append(u.omits, columns...)
+	return u
 }
 
-func (b *UpdateBuilder[T]) OnConflict(conflict clause.OnConflict) *UpdateBuilder[T] {
-	if b.onConflict == nil {
-		b.onConflict = &conflict
+func (u *UpdateBuilder[T]) Eq(col string, val any) *UpdateBuilder[T] {
+	u.expr.Eq(col, val)
+	return u
+}
+
+func (u *UpdateBuilder[T]) Neq(col string, val any) *UpdateBuilder[T] {
+	u.expr.Neq(col, val)
+	return u
+}
+
+func (u *UpdateBuilder[T]) Lt(col string, val any) *UpdateBuilder[T] {
+	u.expr.Lt(col, val)
+	return u
+}
+
+func (u *UpdateBuilder[T]) Lte(col string, val any) *UpdateBuilder[T] {
+	u.expr.Lte(col, val)
+	return u
+}
+
+func (u *UpdateBuilder[T]) Gt(col string, val any) *UpdateBuilder[T] {
+	u.expr.Gt(col, val)
+	return u
+}
+
+func (u *UpdateBuilder[T]) Gte(col string, val any) *UpdateBuilder[T] {
+	u.expr.Gte(col, val)
+	return u
+}
+
+func (u *UpdateBuilder[T]) Between(col string, less, more any) *UpdateBuilder[T] {
+	u.expr.Between(col, less, more)
+	return u
+}
+
+func (u *UpdateBuilder[T]) NotBetween(col string, less, more any) *UpdateBuilder[T] {
+	u.expr.NotBetween(col, less, more)
+	return u
+}
+
+func (u *UpdateBuilder[T]) IsNull(col string) *UpdateBuilder[T] {
+	u.expr.IsNull(col)
+	return u
+}
+
+func (u *UpdateBuilder[T]) NotNull(col string) *UpdateBuilder[T] {
+	u.expr.NotNull(col)
+	return u
+}
+
+func (u *UpdateBuilder[T]) Like(col, tpl string) *UpdateBuilder[T] {
+	u.expr.Like(col, tpl)
+	return u
+}
+
+func (u *UpdateBuilder[T]) NotLike(col, tpl string) *UpdateBuilder[T] {
+	u.expr.NotLike(col, tpl)
+	return u
+}
+
+func (u *UpdateBuilder[T]) In(col string, values ...any) *UpdateBuilder[T] {
+	u.expr.In(col, values...)
+	return u
+}
+
+func (u *UpdateBuilder[T]) NotIn(col string, values ...any) *UpdateBuilder[T] {
+	u.expr.NotIn(col, values...)
+	return u
+}
+
+func (u *UpdateBuilder[T]) When(condition bool, then func(ex *Expr), elses ...func(ex *Expr)) *UpdateBuilder[T] {
+	u.expr.When(condition, then, elses...)
+	return u
+}
+
+func (u *UpdateBuilder[T]) Or(or func(ex *Expr)) *UpdateBuilder[T] {
+	u.expr.Or(or)
+	return u
+}
+
+func (u *UpdateBuilder[T]) And(and func(ex *Expr)) *UpdateBuilder[T] {
+	u.expr.And(and)
+	return u
+}
+
+func (u *UpdateBuilder[T]) Not(not func(ex *Expr)) *UpdateBuilder[T] {
+	u.expr.Not(not)
+	return u
+}
+
+func (u *UpdateBuilder[T]) OnConflict(conflict clause.OnConflict) *UpdateBuilder[T] {
+	if u.onConflict == nil {
+		u.onConflict = &conflict
 	} else {
-		b.onConflict.Columns = conflict.Columns
-		b.onConflict.Where = conflict.Where
-		b.onConflict.TargetWhere = conflict.TargetWhere
-		b.onConflict.OnConstraint = conflict.OnConstraint
-		b.onConflict.DoNothing = conflict.DoNothing
-		b.onConflict.DoUpdates = conflict.DoUpdates
-		b.onConflict.UpdateAll = conflict.UpdateAll
+		u.onConflict.Columns = conflict.Columns
+		u.onConflict.Where = conflict.Where
+		u.onConflict.TargetWhere = conflict.TargetWhere
+		u.onConflict.OnConstraint = conflict.OnConstraint
+		u.onConflict.DoNothing = conflict.DoNothing
+		u.onConflict.DoUpdates = conflict.DoUpdates
+		u.onConflict.UpdateAll = conflict.UpdateAll
 	}
-	return b
+	return u
 }
 
-func (b *UpdateBuilder[T]) Scopes(tx *gorm.DB) *gorm.DB {
-	if b.selects != nil {
-		tx = tx.Select(b.selects)
+func (u *UpdateBuilder[T]) Scopes(tx *gorm.DB) *gorm.DB {
+	if u.selects != nil {
+		tx = tx.Select(u.selects)
 	}
-	if b.omits != nil {
-		tx = tx.Omit(b.omits...)
+	if u.omits != nil {
+		tx = tx.Omit(u.omits...)
 	}
-	return b.Expr.Scopes(tx)
+	return u.expr.Scopes(tx)
 }
 
-func (b *UpdateBuilder[T]) Commit(values map[string]any) (int64, error) {
+func (u *UpdateBuilder[T]) Commit(values map[string]any) (int64, error) {
 	var entity T
-	res := b.db.Model(&entity).Scopes(b.Scopes).Updates(values)
+	res := u.db.Model(&entity).Scopes(u.Scopes).Updates(values)
 	if err := res.Error; err != nil {
 		return res.RowsAffected, err
 	}