diff --git a/models/db/common.go b/models/db/common.go
new file mode 100644
index 0000000000000..1a59a8b5c697f
--- /dev/null
+++ b/models/db/common.go
@@ -0,0 +1,23 @@
+// Copyright 2022 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package db
+
+import (
+	"strings"
+
+	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/util"
+
+	"xorm.io/builder"
+)
+
+// BuildCaseInsensitiveLike returns a condition to check if the given value is like the given key case-insensitively.
+// Handles especially SQLite correctly as UPPER there only transforms ASCII letters.
+func BuildCaseInsensitiveLike(key, value string) builder.Cond {
+	if setting.Database.UseSQLite3 {
+		return builder.Like{"UPPER(" + key + ")", util.ToUpperASCII(value)}
+	}
+	return builder.Like{"UPPER(" + key + ")", strings.ToUpper(value)}
+}
diff --git a/models/issues/issue.go b/models/issues/issue.go
index 064f0d22abd01..5bdb60f7c08c5 100644
--- a/models/issues/issue.go
+++ b/models/issues/issue.go
@@ -27,7 +27,6 @@ import (
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/references"
-	"code.gitea.io/gitea/modules/setting"
 	api "code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/timeutil"
 	"code.gitea.io/gitea/modules/util"
@@ -1903,23 +1902,17 @@ func GetRepoIssueStats(repoID, uid int64, filterMode int, isPull bool) (numOpen,
 func SearchIssueIDsByKeyword(ctx context.Context, kw string, repoIDs []int64, limit, start int) (int64, []int64, error) {
 	repoCond := builder.In("repo_id", repoIDs)
 	subQuery := builder.Select("id").From("issue").Where(repoCond)
-	// SQLite's UPPER function only transforms ASCII letters.
-	if setting.Database.UseSQLite3 {
-		kw = util.ToUpperASCII(kw)
-	} else {
-		kw = strings.ToUpper(kw)
-	}
 	cond := builder.And(
 		repoCond,
 		builder.Or(
-			builder.Like{"UPPER(name)", kw},
-			builder.Like{"UPPER(content)", kw},
+			db.BuildCaseInsensitiveLike("name", kw),
+			db.BuildCaseInsensitiveLike("content", kw),
 			builder.In("id", builder.Select("issue_id").
 				From("comment").
 				Where(builder.And(
 					builder.Eq{"type": CommentTypeComment},
 					builder.In("issue_id", subQuery),
-					builder.Like{"UPPER(content)", kw},
+					db.BuildCaseInsensitiveLike("content", kw),
 				)),
 			),
 		),
diff --git a/models/issues/milestone.go b/models/issues/milestone.go
index c49799f391dc3..1021938b205ae 100644
--- a/models/issues/milestone.go
+++ b/models/issues/milestone.go
@@ -361,7 +361,7 @@ func (opts GetMilestonesOption) toCond() builder.Cond {
 	}
 
 	if len(opts.Name) != 0 {
-		cond = cond.And(builder.Like{"UPPER(name)", strings.ToUpper(opts.Name)})
+		cond = cond.And(db.BuildCaseInsensitiveLike("name", opts.Name))
 	}
 
 	return cond