Fix bug

models/issues/issue_project.go

 
 import (
 	"context"
+	"database/sql"
 	"fmt"
 
 	"code.gitea.io/gitea/models/db"
 			return nil
 		}
 
-		var maxSorting int64
-		has, err := db.GetEngine(ctx).Select("Max(sorting)").Table("project_issue").
+		var maxSorting sql.NullInt64
+		if _, err := db.GetEngine(ctx).Select("Max(sorting)").Table("project_issue").
 			Where("project_id=?", newProjectID).
 			And("project_board_id=?", newColumnID).
-			Get(&maxSorting)
-		if err != nil {
+			Get(&maxSorting); err != nil {
 			return err
 		}
-		if has {
-			maxSorting++
+		if maxSorting.Valid {
+			maxSorting.Int64++
 		}
 
 		return db.Insert(ctx, &project_model.ProjectIssue{
 			IssueID:        issue.ID,
 			ProjectID:      newProjectID,
 			ProjectBoardID: newColumnID,
-			Sorting:        maxSorting,
+			Sorting:        maxSorting.Int64,
 		})
 	})
 }

models/project/board.go

 
 import (
 	"context"
+	"database/sql"
 	"errors"
 	"fmt"
 	"regexp"
 	}
 
 	if totalColumns > 0 {
-		var maxSorting int8
-		has, err := db.GetEngine(ctx).Select("Max(sorting)").Table("project_board").
-			Where("project_id=?", board.ProjectID).Get(&maxSorting)
-		if err != nil {
+		var maxSorting sql.NullByte
+		if _, err := db.GetEngine(ctx).Select("Max(sorting)").Table("project_board").
+			Where("project_id=?", board.ProjectID).Get(&maxSorting); err != nil {
 			return err
 		}
-		if has {
-			board.Sorting = maxSorting + 1
+		if maxSorting.Valid {
+			board.Sorting = int8(maxSorting.Byte) + 1
 		}
 	}
 

models/project/issue.go

 
 import (
 	"context"
+	"database/sql"
 	"fmt"
 
 	"code.gitea.io/gitea/models/db"
 		return nil
 	}
 
-	var maxSorting int8
-	has, err := db.GetEngine(ctx).Select("Max(sorting)").Table("project_issue").
+	var maxSorting sql.NullByte
+	if _, err := db.GetEngine(ctx).Select("Max(sorting)").Table("project_issue").
 		Where("project_id=?", newColumn.ProjectID).
 		And("project_board_id=?", newColumn.ID).
-		Get(&maxSorting)
-	if err != nil {
+		Get(&maxSorting); err != nil {
 		return err
 	}
-	if has {
-		maxSorting++
+	if maxSorting.Valid {
+		maxSorting.Byte++
 	}
 
 	issues, err := b.GetIssues(ctx)
 	return db.WithTx(ctx, func(ctx context.Context) error {
 		for i, issue := range issues {
 			issue.ProjectBoardID = newColumn.ID
-			issue.Sorting = int64(maxSorting) + int64(i)
+			issue.Sorting = int64(maxSorting.Byte) + int64(i)
 			if _, err := db.GetEngine(ctx).ID(issue.ID).Cols("project_board_id", "sorting").Update(issue); err != nil {
 				return err
 			}