fix: avoid placeholder detection in SQL comments

bind.go

@@ -82,8 +82,9 @@ func bind(tz *time.Location, query string, args ...any) (string, error) {
 		return bindNamed(tz, query, args...)
 	}
 
-	haveNumeric = bindNumericRe.MatchString(query)
-	havePositional = bindPositionalRe.MatchString(query)
+	cleanQuery := stripLineComments(query)
+	haveNumeric = bindNumericRe.MatchString(cleanQuery)
+	havePositional = bindPositionalRe.MatchString(cleanQuery)
 	if haveNumeric && havePositional {
 		return "", ErrBindMixedParamsFormats
 	}
@@ -93,6 +94,18 @@ func bind(tz *time.Location, query string, args ...any) (string, error) {
 	return bindPositional(tz, query, args...)
 }
 
+// stripLineComments removes `--` style line comments from SQL queries.
+// This avoids false-positive placeholder matches (e.g. `?` or `$1`) inside comments during bind() processing.
+func stripLineComments(query string) string {
+	lines := strings.Split(query, "\n")
+	for i, line := range lines {
+		if idx := strings.Index(line, "--"); idx != -1 {
+			lines[i] = line[:idx]
+		}
+	}
+	return strings.Join(lines, "\n")
+}
+
 func checkAllNamedArguments(args ...any) (bool, error) {
 	var (
 		haveNamed     bool

tests/issues/1537_test.go

@@ -0,0 +1,26 @@
+package issues
+
+import (
+	"context"
+	"testing"
+
+	"github.com/ClickHouse/clickhouse-go/v2/tests"
+	"github.com/stretchr/testify/require"
+)
+
+func TestIssue1537_MixedPlaceholdersAndComment(t *testing.T) {
+	ctx := context.Background()
+
+	conn, err := tests.GetConnection("issues", nil, nil, nil)
+	require.NoError(t, err)
+	defer conn.Close()
+
+	// PostgreSQL-style placeholder in query; `?` is in comment and should be ignored
+	row := conn.QueryRow(ctx, "SELECT $1 -- some comment with ?", "clickhouse")
+
+	var s string
+	err = row.Scan(&s)
+	require.NoError(t, err)
+	require.Equal(t, "clickhouse", s)
+}
+