refactor:

- source 初始化数据 new 实现
- service mysql 与 pgsql 分开实现
- 代码备注优化

server/source/example/file.go

@@ -0,0 +1,34 @@
+package example
+
+import (
+	"github.com/flipped-aurora/gin-vue-admin/server/global"
+	"github.com/flipped-aurora/gin-vue-admin/server/model/example"
+	"github.com/pkg/errors"
+	"gorm.io/gorm"
+)
+
+var File = new(file)
+
+type file struct{}
+
+func (f *file) TableName() string {
+	return "exa_file_upload_and_downloads"
+}
+
+func (f *file) Initialize() error {
+	entities := []example.ExaFileUploadAndDownload{
+		{Name: "10.png", Url: "https://qmplusimg.henrongyi.top/gvalogo.png", Tag: "png", Key: "158787308910.png"},
+		{Name: "logo.png", Url: "https://qmplusimg.henrongyi.top/1576554439myAvatar.png", Tag: "png", Key: "1587973709logo.png"},
+	}
+	if err := global.GVA_DB.Create(&entities).Error; err != nil {
+		return errors.Wrap(err, f.TableName()+"表数据初始化失败!")
+	}
+	return nil
+}
+
+func (f *file) CheckDataExist() bool {
+	if errors.Is(global.GVA_DB.Where("name = ? AND key = ?", "logo.png", "1587973709logo.png").First(&example.ExaFileUploadAndDownload{}).Error, gorm.ErrRecordNotFound) {
+		return false
+	}
+	return true
+}