> ## Documentation Index
> Fetch the complete documentation index at: https://docs.risingwave.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Supported protobuf types

> RisingWave supports a variety of protobuf data types, which are converted to equivalent types in RisingWave. This page provides an overview of the supported protobuf types and their corresponding RisingWave types.

## Conversion

RisingWave converts [well-known types](https://protobuf.dev/reference/protobuf/google.protobuf/) from the protobuf library to specific types in RisingWave. The conversion is as follows:

| Protobuf type               | RisingWave type                                                                        |
| :-------------------------- | :------------------------------------------------------------------------------------- |
| any                         | `jsonb`                                                                                |
| double                      | `double precision`                                                                     |
| float                       | `real`                                                                                 |
| int32                       | `int`                                                                                  |
| int64                       | `bigint`                                                                               |
| uint32                      | `bigint`                                                                               |
| uint64                      | `decimal`                                                                              |
| sint32                      | `int`                                                                                  |
| sint64                      | `bigint`                                                                               |
| fixed32                     | `bigint`                                                                               |
| fixed64                     | `decimal`                                                                              |
| sfixed32                    | `int`                                                                                  |
| sfixed64                    | `bigint`                                                                               |
| bool                        | `boolean`                                                                              |
| string                      | `varchar`                                                                              |
| bytes                       | `bytea`                                                                                |
| enum                        | `varchar`                                                                              |
| message                     | `struct`. See details in [Nested messages](#nested-messages).                          |
| messages\_as\_jsonb         | `jsonb`. See details in [Handle recursive definitions](#handle-recursive-definitions). |
| repeated                    | `array`                                                                                |
| map                         | `map`. See details in [Map](/sql/data-types/map-type).                                 |
| google.protobuf.Struct      | Not supported                                                                          |
| google.protobuf.Timestamp   | `struct<seconds bigint, nanos int>`                                                    |
| google.protobuf.Duration    | `struct<seconds bigint, nanos int>`                                                    |
| google.protobuf.Any         | `struct<type_url varchar, value bytea>`                                                |
| google.protobuf.Int32Value  | `struct<value int>`                                                                    |
| google.protobuf.StringValue | `struct<value varchar>`                                                                |

### Nested messages

The nested fields are transformed into columns within a struct type. For example, a Protobuf message with the following structure:

```protobuf Example theme={null}
message NestedMessage {
  int32 id = 1;
  string name = 2;
}
```

Will be converted to `struct<id int, name varchar>` in RisingWave.

### Handle recursive definitions

When detecting a recursive definition in the protobuf, RisingWave will reject the statement and show the circular dependency. Adding dependency items to `messages_as_jsonb` with full type name separated by comma can solve the case. For example:

```sql theme={null}
CREATE TABLE opentelemetry_test 
WITH ( 
    ${RISEDEV_KAFKA_WITH_OPTIONS_COMMON}, 
    topic = 'opentelemetry_test' 
) 
FORMAT PLAIN 
ENCODE PROTOBUF ( 
    schema.registry = '${RISEDEV_SCHEMA_REGISTRY_URL}', 
    message = 'opentelemetry_test.OTLPTestMessage', 
    messages_as_jsonb = 'opentelemetry.proto.common.v1.ArrayValue,opentelemetry.proto.common.v1.KeyValueList,opentelemetry.proto.common.v1.AnyValue'
);
```

## Field presence

RisingWave correctly handles [protobuf field presence](https://protobuf.dev/programming-guides/field_presence/) to distinguish between missing fields and fields explicitly set to their default values. The handling depends on the field type:

### Regular primitive fields

Regular primitive fields (without the `optional` keyword) receive their default values when absent from the protobuf message:

```protobuf Example theme={null}
syntax = "proto3";
message Example {
  int32 regular_int = 1;      // Gets 0 if missing
  string regular_string = 2;  // Gets "" if missing
  bool regular_bool = 3;      // Gets false if missing
}
```

### Optional fields

Fields marked with the `optional` keyword are set to `NULL` when absent:

```protobuf Example theme={null}
syntax = "proto3";
message Example {
  optional int32 optional_int = 1;      // Gets NULL if missing
  optional string optional_string = 2;  // Gets NULL if missing
}
```

### Message fields

Message fields (nested messages) are set to `NULL` when absent:

```protobuf Example theme={null}
syntax = "proto3";
message InnerMessage {
  string content = 1;
}
message Example {
  InnerMessage inner = 1;  // Gets NULL if missing
}
```

### Oneof fields

Fields within a `oneof` group are set to `NULL` when the `oneof` is not set or a different field in the group is set:

```protobuf Example theme={null}
syntax = "proto3";
message Example {
  oneof test_oneof {
    string oneof_string = 1;  // NULL if oneof_int is set or if oneof is not set
    int32 oneof_int = 2;      // NULL if oneof_string is set or if oneof is not set
  }
}
```

Only one field within a `oneof` can be non-NULL at a time.

## Related topics

* [CREATE SOURCE](/sql/commands/sql-create-source/)