risingwavelabs/risingwave · error · AccessError

Cannot parse value ` ` with type ` ` into expected type

Error message

Cannot parse value `{value}` with type `{got}` into expected type `{expected}`

What it means

AccessError::TypeError in src/connector/codec/src/decoder/mod.rs:30. Thrown when a decoded value cannot be parsed/coerced into the expected RisingWave type: the value's actual runtime type (`got`) differs from the target column type (`expected`).

Solutions

1. Fix the upstream producer to emit values matching the declared column types
2. Recreate the RW source/table with types matching the payload (e.g. change INTEGER to VARCHAR if payload is textual)
3. Add a cast in the downstream materialized view, e.g. `CAST(field AS VARCHAR)`, after declaring the column permissively
4. Inspect the `value`, `got`, `expected` fields in the error to pinpoint the exact offending record and field

Example fix

-- before
count INTEGER
-- after (payload sends "123" as string)
count VARCHAR  -- then use count::INTEGER in queries

fn value_matches_expected(v: &serde_json::Value, expected: &str) -> bool {
    match (expected, v) {
        ("integer" | "bigint", serde_json::Value::Number(n)) => n.is_i64() || n.is_u64(),
        ("varchar", serde_json::Value::String(_)) => true,
        ("boolean", serde_json::Value::Bool(_)) => true,
        _ => false,
    }
}

match accessor.access(record, field) {
    Ok(v) => v,
    Err(AccessError::TypeError { expected, got, value }) => {
        tracing::warn!(%expected, %got, %value, "type mismatch; coercing");
        // fall back to string decode or default
    }
    Err(e) => return Err(e.into()),
}

When it happens

Trigger: A decoder accessor converts a raw value (JSON/Avro/Protobuf datum) into a RisingWave datum of the expected physical type and the wire value is of another type — e.g. a JSON string "abc" decoded into an INTEGER column, or a number decoded into a VARCHAR column without conversion.

Common situations: Producers writing wrong-typed values (sending strings for numeric fields, nulls as strings); schema registry mismatch between declared and actual Avro union branch; type changed upstream after the RW table was created.

Understand the failure class

Background: Type mismatch errors: IllegalArgumentException, TypeError and type guards across 150 open-source libraries — this error's family across 150 libraries.

Related errors

• {0}
• argument type mismatch, expect
• Array error
• Can't cast string to date (expected format is YYYY-MM-DD)
• Can't cast string to time

AI-assisted analysis of risingwavelabs/risingwave@6469eb736d (2026-09-11). Data as JSON: /api/errors/e2ecd9833621f271. Report an issue: GitHub.

Appendix: source

Thrown at src/connector/codec/src/decoder/mod.rs:30

// See the License for the specific language governing permissions and
// limitations under the License.

pub mod avro;
pub mod json;
pub mod protobuf;
pub mod utils;

use risingwave_common::error::NotImplemented;
use risingwave_common::types::{DataType, Datum, DatumCow, ToOwnedDatum};
use thiserror::Error;
use thiserror_ext::Macro;

#[derive(Error, Debug, Macro)]
#[thiserror_ext(macro(mangle, path = "crate::decoder"))]
pub enum AccessError {
    #[error("Undefined field `{name}` at `{path}`")]
    Undefined { name: String, path: String },
    #[error("Cannot parse value `{value}` with type `{got}` into expected type `{expected}`")]
    TypeError {
        expected: String,
        got: String,
        value: String,
    },
    #[error("Unsupported data type `{ty}`")]
    UnsupportedType { ty: String },

    /// CDC auto schema change specific error that may include table context
    #[error("CDC auto schema change error: unsupported data type `{ty}` in table `{table_name}`")]
    CdcAutoSchemaChangeError { ty: String, table_name: String },

    #[error("Unsupported additional column `{name}`")]
    UnsupportedAdditionalColumn { name: String },

    #[error("Fail to convert protobuf Any into jsonb: {0}")]
    ProtobufAnyToJson(#[source] serde_json::Error),

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