Use correct count for `NumOpenIssues` (#19980)

- Don't specify the field in `Count` instead use `Cols` for this.
- Call `log.Error` when a error occur.

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

models/project/issue.go

@@ -9,6 +9,7 @@ import (
 	"fmt"
 
 	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/modules/log"
 )
 
 // ProjectIssue saves relation from issue to a project
@@ -41,6 +42,7 @@ func (p *Project) NumIssues() int {
 		Cols("issue_id").
 		Count()
 	if err != nil {
+		log.Error("NumIssues: %v", err)
 		return 0
 	}
 	return int(c)
@@ -54,6 +56,7 @@ func (p *Project) NumClosedIssues() int {
 		Cols("issue_id").
 		Count()
 	if err != nil {
+		log.Error("NumClosedIssues: %v", err)
 		return 0
 	}
 	return int(c)
@@ -63,8 +66,11 @@ func (p *Project) NumClosedIssues() int {
 func (p *Project) NumOpenIssues() int {
 	c, err := db.GetEngine(db.DefaultContext).Table("project_issue").
 		Join("INNER", "issue", "project_issue.issue_id=issue.id").
-		Where("project_issue.project_id=? AND issue.is_closed=?", p.ID, false).Count("issue.id")
+		Where("project_issue.project_id=? AND issue.is_closed=?", p.ID, false).
+		Cols("issue_id").
+		Count()
 	if err != nil {
+		log.Error("NumOpenIssues: %v", err)
 		return 0
 	}
 	return int(c)