{"record":{"id":"bc4bd3c07bf0de16","repo":"risingwavelabs/risingwave","slug":"failed-to-bind-expression-expr-error","errorCode":null,"errorMessage":"Failed to bind expression: {expr}: {error}","messagePattern":"Failed to bind expression: (.+?): (.+?)","errorType":"error_code","errorClass":"ErrorCode::BindErrorRoot","httpStatus":null,"severity":"error","filePath":"src/frontend/src/error.rs","lineNumber":121,"sourceCode":"        #[backtrace]\n        #[source]\n        BoxedError,\n    ),\n    // TODO(error-handling): there's a limitation that `#[transparent]` can't be used with `#[backtrace]` if no `#[from]`\n    // So we emulate a transparent error with \"{0}\" display here.\n    #[error(\"{0}\")]\n    RpcError(\n        #[source]\n        #[backtrace]\n        // `tonic::transport::Error`, `TonicStatusWrapper`, or `RpcError`\n        BoxedError,\n    ),\n    // TODO: use a new type for bind error\n    // TODO(error-handling): should prefer use error types than strings.\n    #[error(\"Bind error: {0}\")]\n    BindError(#[message] String),\n    // TODO: only keep this one\n    #[error(\"Failed to bind expression: {expr}: {error}\")]\n    BindErrorRoot {\n        expr: String,\n        #[source]\n        #[backtrace]\n        error: BoxedError,\n    },\n    #[error(transparent)]\n    CastError(\n        #[from]\n        #[backtrace]\n        CastError,\n    ),\n    #[error(\"Catalog error: {0}\")]\n    CatalogError(\n        #[source]\n        #[backtrace]\n        #[message]\n        BoxedError,","sourceCodeStart":103,"sourceCodeEnd":139,"githubUrl":"https://github.com/risingwavelabs/risingwave/blob/6469eb736d691e8e9b8a419a57edd6429ca77417/src/frontend/src/error.rs#L103-L139","documentation":"`ErrorCode::BindErrorRoot` is the structured bind error carrying both the failing expression text (`expr`) and the underlying cause as `BoxedError` (`error`, marked `#[source]`). It is the preferred variant (per the 'only keep this one' TODO) so callers see exactly which expression failed to bind and why.","triggerScenarios":"Any expression in a statement that the binder cannot resolve or type-check: unknown columns/functions/operators, wrong argument types, unsupported operators on the given operand types.","commonSituations":"Typos in column names, referencing a column not present in the FROM scope, implicit casts that don't exist, using batch-only functions in streaming contexts.","solutions":["Read the `expr` field to pinpoint the failing sub-expression and the chained `error` for the reason","Fix the identifier typo or qualify the column/table name","Insert explicit casts to satisfy the operator's signature","Verify the function/operator exists in RisingWave (some Postgres functions are unimplemented)"],"exampleFix":"-- before\nSELECT amount + created_at FROM orders; -- Failed to bind expression: amount + created_at: type mismatch\n-- after\nSELECT amount + extract(epoch from created_at) FROM orders;","handlingStrategy":"validation","validationCode":"-- pre-check the exact expression on sample data\nSELECT amount + extract(epoch from created_at) FROM orders LIMIT 1;","typeGuard":"fn is_bind_root(e: &RwError) -> bool { matches!(e.get_code(), ErrorCode::BindErrorRoot { .. }) }","tryCatchPattern":"if let ErrorCode::BindErrorRoot { expr, error } = err.get_code() { eprintln!(\"expr `{expr}` failed: {error}\"); }","preventionTips":["Read the expr field first — it localizes the failure precisely","Use explicit casts to satisfy operator signatures","Validate identifiers/columns exist in scope before submitting","Test new expressions with LIMIT 1 queries before production use"],"tags":["binder","sql","expression"],"backgroundTag":"invalid-argument-value","analyzedSha":"6469eb736d691e8e9b8a419a57edd6429ca77417","analyzedAt":"2026-09-11T21:06:21.487Z","contentChangedAt":"2026-09-11T21:06:21.487Z","schemaVersion":2},"datasetVersion":"2026-09-14T16:17:12.679Z"}