ginExample/models/subject.go

package models

import (
	"fmt"
	"gorm.io/gorm"
	"product/backend/moo/db"
)

type Subject struct {
	// body
	Title  string `gorm:"type:varchar(255)" json:"title"`
	Intro  string `gorm:"type:varchar(255)" json:"intro"`
	Logo   string `gorm:"type:varchar(255)" json:"logo"`
	Type   string `gorm:"type:enum('common', 'special')" json:"type"`
	Remark string `gorm:"type:varchar(1023)" json:"remark"`
	Order  int    `gorm:"" json:"order"`
	State  bool   `gorm:"" json:"state"`

	// basic models
	Model

	// association
	KnowledgeGroups []KnowledgeGroup `gorm:"foreignKey:SubjectID" json:"knowledgeGroups"`
	DirectiveGroups []DirectiveGroup `gorm:"foreignKey:SubjectID" json:"directiveGroups"`
	ProductGroups   []ProductGroup   `gorm:"foreignKey:SubjectID" json:"productGroups"`
	LessonTypes     []LessonType     `gorm:"foreignKey:SubjectID" json:"lessonTypes"`
}

// methods

func SubjectRow(id uint, withKnowledgeGroup, withDirectiveGroup, withProductGroup, withLessonType bool) (Subject, error) {
	// model
	row := Subject{}
	if err := db.DB.First(&row, id).Error; err != nil {
		return row, err
	}

	// with association
	if withKnowledgeGroup {
		_ = db.DB.Model(&row).Association("KnowledgeGroups").Find(&row.KnowledgeGroups)
	}

	if withDirectiveGroup {
		_ = db.DB.Model(&row).Association("DirectiveGroups").Find(&row.DirectiveGroups)
	}
	if withProductGroup {
		_ = db.DB.Model(&row).Association("ProductGroups").Find(&row.ProductGroups)
	}
	if withLessonType {
		_ = db.DB.Model(&row).Association("LessonTypes").Find(&row.LessonTypes)
	}

	return row, nil
}

func SubjectRows(pager Pager, withTotal bool, keyword string, sType string, withKnowledgeGroup, withDirectiveGroup, withProductGroup, withLessonType bool) ([]Subject, int64, error) {

	// query
	query := db.DB.Model(&Subject{})

	// filter
	// keyword
	if sType != "" {
		query.Where("type == ?", sType)
	}
	// keyword
	if keyword != "" {
		query.Where("title LIKE ?", keyword+"%")
	}

	// fetch total
	var total int64
	if withTotal {
		query.Count(&total)
	}

	// order
	query.Order(fmt.Sprintf("`%s` %s", pager.SortField, pager.SortOrder))

	// # offset limit
	offset := -1 // 不限制
	if pager.PageSize > 0 {
		offset = (pager.PageIndex - 1) * pager.PageSize
	}
	query.Offset(offset).Limit(pager.PageSize)

	// select
	query.Select("*")

	// fetch
	var rows []Subject
	if result := query.Find(&rows); result.Error != nil {
		return rows, 0, result.Error
	}

	// with association
	for i, _ := range rows {
		if withKnowledgeGroup {
			_ = db.DB.Model(&rows[i]).Association("KnowledgeGroups").Find(&rows[i].KnowledgeGroups)
		}
		if withDirectiveGroup {
			_ = db.DB.Model(&rows[i]).Association("DirectiveGroups").Find(&rows[i].DirectiveGroups)
		}
		if withProductGroup {
			_ = db.DB.Model(&rows[i]).Association("ProductGroups").Find(&rows[i].ProductGroups)
		}
		if withLessonType {
			_ = db.DB.Model(&rows[i]).Association("LessonTypes").Find(&rows[i].LessonTypes)
		}
	}

	return rows, total, nil
}

func SubjectRowDel(id uint) error {
	// db tx
	return db.DB.Transaction(func(tx *gorm.DB) error {
		// model delete
		if result := tx.Delete(&Subject{}, id); result.Error != nil {
			return result.Error
		}

		// association delete

		return nil
	})
}

func SubjectRowUpdate(model *Subject) error {
	// db tx
	return db.DB.Transaction(func(tx *gorm.DB) error {
		// model update
		if result := tx.Updates(&model); result.Error != nil {
			return result.Error
		}

		// association update

		return nil
	})
}

// default value
const (
	subjectDefaultType = "common"
)

func SubjectRowInsert(model *Subject) error {
	// default value
	if model.Type == "" {
		model.Type = subjectDefaultType
	}
	// db tx
	return db.DB.Transaction(func(tx *gorm.DB) error {

		// model create
		if result := tx.Create(&model); result.Error != nil {
			return result.Error
		}

		// association create

		return nil
	})
}