fix: support scan float32 to float32

Close uptrace#1087

schema/scan.go

@@ -38,7 +38,7 @@ func init() {
 		reflect.Uint32:        scanUint64,
 		reflect.Uint64:        scanUint64,
 		reflect.Uintptr:       scanUint64,
-		reflect.Float32:       scanFloat64,
+		reflect.Float32:       scanFloat32,
 		reflect.Float64:       scanFloat64,
 		reflect.Complex64:     nil,
 		reflect.Complex128:    nil,
@@ -214,6 +214,36 @@ func scanUint64(dest reflect.Value, src interface{}) error {
 	}
 }
 
+func scanFloat32(dest reflect.Value, src interface{}) error {
+	switch src := src.(type) {
+	case nil:
+		dest.SetFloat(0)
+		return nil
+	case float32:
+		dest.SetFloat(float64(src))
+		return nil
+	case float64:
+		dest.SetFloat(src)
+		return nil
+	case []byte:
+		f, err := strconv.ParseFloat(internal.String(src), 64)
+		if err != nil {
+			return err
+		}
+		dest.SetFloat(f)
+		return nil
+	case string:
+		f, err := strconv.ParseFloat(src, 64)
+		if err != nil {
+			return err
+		}
+		dest.SetFloat(f)
+		return nil
+	default:
+		return scanError(dest.Type(), src)
+	}
+}
+
 func scanFloat64(dest reflect.Value, src interface{}) error {
 	switch src := src.(type) {
 	case nil: