From 780e1797a612e25bccdbc810bfa77862ea16cd9c Mon Sep 17 00:00:00 2001
From: demoManito <1430482733@qq.com>
Date: Mon, 30 Sep 2024 18:28:30 +0800
Subject: [PATCH] feature: add exists method

---
 finisher_api.go     |  6 ++++++
 tests/query_test.go | 22 ++++++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/finisher_api.go b/finisher_api.go
index 6802945cc..7d3bb24fc 100644
--- a/finisher_api.go
+++ b/finisher_api.go
@@ -502,6 +502,12 @@ func (db *DB) Count(count *int64) (tx *DB) {
 	return
 }
 
+// Exists checks if there is any record matching the given conditions
+func (db *DB) Exists() (bool, error) {
+	var exists bool
+	return exists, db.Session(&Session{NewDB: true}).Raw("SELECT ?", Expr("EXISTS(?)", db.Select("1"))).Pluck("exists", &exists).Error
+}
+
 func (db *DB) Row() *sql.Row {
 	tx := db.getInstance().Set("rows", false)
 	tx = tx.callbacks.Row().Execute(tx)
diff --git a/tests/query_test.go b/tests/query_test.go
index 566763c51..ead5fe87a 100644
--- a/tests/query_test.go
+++ b/tests/query_test.go
@@ -1453,3 +1453,25 @@ func TestQueryScanToArray(t *testing.T) {
 		t.Error("users[1] should be empty")
 	}
 }
+
+func TestExists(t *testing.T) {
+	if DB.Dialector.Name() == "sqlserver" {
+		t.Skip()
+	}
+
+	ok, err := DB.Table("users").Where("name = ?", "jinzhu").Exists()
+	if err != nil {
+		t.Fatalf("Failed to scan, got %v", err)
+	}
+	if !ok {
+		t.Errorf("Should found record")
+	}
+
+	ok, err = DB.Table("users").Where("name = ?", "jinzhu-jinzhu").Exists()
+	if err != nil {
+		t.Fatalf("Failed to scan, got %v", err)
+	}
+	if ok {
+		t.Errorf("Should not found record")
+	}
+}