Convert db backend to use Gorm, with basis for support

for Mysql and Postgres in addition to existing Sqlite

backend/internal/entity/scopes.go

@@ -0,0 +1,62 @@
+package entity
+
+import (
+	"strings"
+
+	"npm/internal/model"
+
+	"gorm.io/gorm"
+)
+
+func ScopeOffsetLimit(pageInfo *model.PageInfo) func(db *gorm.DB) *gorm.DB {
+	return func(db *gorm.DB) *gorm.DB {
+		if pageInfo.Offset > 0 || pageInfo.Limit > 0 {
+			return db.Limit(pageInfo.Limit).Offset(pageInfo.Offset)
+		}
+		return db
+	}
+}
+
+func ScopeOrderBy(pageInfo *model.PageInfo, defaultSort model.Sort) func(db *gorm.DB) *gorm.DB {
+	return func(db *gorm.DB) *gorm.DB {
+		if pageInfo.Sort != nil {
+			// Sort by items in slice
+			return db.Order(sortToOrderString(pageInfo.Sort))
+		} else if defaultSort.Field != "" {
+			// Default to this sort
+			str := defaultSort.Field
+			if defaultSort.Direction != "" {
+				str = str + " " + defaultSort.Direction
+			}
+			return db.Order(str)
+		}
+		return db
+	}
+}
+
+func ScopeFilters(filters map[string]string) func(db *gorm.DB) *gorm.DB {
+	return func(db *gorm.DB) *gorm.DB {
+		// todo
+		/*
+			if filters != nil {
+				filterMap := GetFilterMap(m)
+				filterQuery, filterParams := GenerateSQLFromFilters(filters, filterMap, filterMapFunctions)
+				whereStrings = []string{filterQuery}
+				params = append(params, filterParams...)
+			}
+		*/
+		return db
+	}
+}
+
+func sortToOrderString(sorts []model.Sort) string {
+	strs := make([]string, 0)
+	for _, i := range sorts {
+		str := i.Field
+		if i.Direction != "" {
+			str = str + " " + i.Direction
+		}
+		strs = append(strs, str)
+	}
+	return strings.Join(strs, ", ")
+}