Method evalJSON

pkg/expression/builtin_cast.go:666–698

(ctx EvalContext, row chunk.Row)

}

func (b *castJSONAsArrayFunctionSig) evalJSON(ctx EvalContext, row chunk.Row) (res types.BinaryJSON, isNull bool, err error) {
	val, isNull, err := b.args[0].EvalJSON(ctx, row)
	if isNull || err != nil {
		return res, isNull, err
	}

	if val.TypeCode == types.JSONTypeCodeObject {
		return types.BinaryJSON{}, false, ErrNotSupportedYet.GenWithStackByArgs("CAST-ing JSON OBJECT type to array")
	}

	arrayVals := make([]any, 0, 8)
	ft := b.tp.ArrayType()
	f := convertJSON2Tp(ft.EvalType())
	if f == nil {
		return types.BinaryJSON{}, false, ErrNotSupportedYet.GenWithStackByArgs(fmt.Sprintf("CAS-ing data to array of %s", ft.String()))
	}
	if val.TypeCode != types.JSONTypeCodeArray {
		item, err := f(fakeSctx, val, ft)
		if err != nil {
			return types.BinaryJSON{}, false, err
		}
		arrayVals = append(arrayVals, item)
	} else {
		for i := 0; i < val.GetElemCount(); i++ {
			item, err := f(fakeSctx, val.ArrayGetElem(i), ft)
			if err != nil {
				return types.BinaryJSON{}, false, err
			}
			arrayVals = append(arrayVals, item)
		}
	}
	return types.CreateBinaryJSON(arrayVals), false, nil
}

// ConvertJSON2Tp converts JSON to the specified type.
func ConvertJSON2Tp(v types.BinaryJSON, targetType *types.FieldType) (any, error) {