Support Raw func support use Limit method

callbacks/query.go

@@ -28,13 +28,28 @@ func Query(db *gorm.DB) {
 }
 
 func BuildQuerySQL(db *gorm.DB) {
+	var hasLimitClause bool
+	sqlStr := db.Statement.SQL.String()
 	if db.Statement.Schema != nil && !db.Statement.Unscoped {
 		for _, c := range db.Statement.Schema.QueryClauses {
 			db.Statement.AddClause(c)
 		}
 	}
 
-	if db.Statement.SQL.String() == "" {
+	for cla, _ := range db.Statement.Clauses {
+		if cla == "LIMIT" {
+			hasLimitClause = true
+		}
+	}
+
+	if sqlStr != "" && !strings.Contains(strings.ToUpper(sqlStr), "LIMIT") && hasLimitClause {
+		if !strings.HasSuffix(db.Statement.SQL.String(), " ") {
+			db.Statement.SQL.WriteByte(' ')
+		}
+		db.Statement.Build("LIMIT")
+	}
+
+	if sqlStr == "" {
 		db.Statement.SQL.Grow(100)
 		clauseSelect := clause.Select{Distinct: db.Statement.Distinct}
 

chainable_api_test.go

@@ -0,0 +1,35 @@
+package gorm_test
+
+import (
+	"gorm.io/gorm/callbacks"
+	"gorm.io/gorm/utils/tests"
+	"strings"
+	"testing"
+
+	"gorm.io/gorm"
+)
+
+func TestDB_Raw_Limit(t *testing.T) {
+	var (
+		t1 *gorm.DB
+		t2 *gorm.DB
+		t3 *gorm.DB
+	)
+	tx, _ := gorm.Open(
+		tests.DummyDialector{},
+		//&gorm.Config{Logger: logger.Default.LogMode(logger.Info)},
+	)
+	t1 = tx.Table("pod_events").Limit(1)
+	t2 = tx.Raw("SELECT * FROM `pod_events`").Limit(1)
+	t3 = tx.Raw("SELECT * FROM `pod_events` LIMIT 1").Limit(1)
+	t1.Statement.BuildClauses = []string{"SELECT", "FROM", "WHERE", "GROUP BY", "ORDER BY", "LIMIT", "FOR"}
+	callbacks.BuildQuerySQL(t1)
+	callbacks.BuildQuerySQL(t2)
+	callbacks.BuildQuerySQL(t3)
+	s1 := t1.Statement.SQL.String()
+	s2 := t2.Statement.SQL.String()
+	s3 := t3.Statement.SQL.String()
+	if !strings.EqualFold(s1, s2) || !strings.EqualFold(s1, s3) {
+		t.Errorf("s1 != s2 != s3\ns1 = %v\ns2 = %v\ns3 = %v\n", s1, s2, s3)
+	}
+}