{"record":{"id":"b13ba1c5a7b68fff","repo":"apache/flink","slug":"unsupported-type-information-s-for-field-s","errorCode":null,"errorMessage":"Unsupported type information '%s' for field '%s'.","messagePattern":"Unsupported type information '(.+?)' for field '(.+?)'\\.","errorType":"exception","errorClass":"IllegalArgumentException","httpStatus":null,"severity":"error","filePath":"flink-formats/flink-csv/src/main/java/org/apache/flink/formats/csv/CsvRowSchemaConverter.java","lineNumber":200,"sourceCode":"        } else if (BOOLEAN_TYPES.contains(info)) {\n            return CsvSchema.ColumnType.BOOLEAN;\n        } else if (info instanceof ObjectArrayTypeInfo) {\n            validateNestedField(fieldName, ((ObjectArrayTypeInfo) info).getComponentInfo());\n            return CsvSchema.ColumnType.ARRAY;\n        } else if (info instanceof BasicArrayTypeInfo) {\n            validateNestedField(fieldName, ((BasicArrayTypeInfo) info).getComponentInfo());\n            return CsvSchema.ColumnType.ARRAY;\n        } else if (info instanceof RowTypeInfo) {\n            final TypeInformation<?>[] types = ((RowTypeInfo) info).getFieldTypes();\n            for (TypeInformation<?> type : types) {\n                validateNestedField(fieldName, type);\n            }\n            return CsvSchema.ColumnType.ARRAY;\n        } else if (info instanceof PrimitiveArrayTypeInfo\n                && ((PrimitiveArrayTypeInfo) info).getComponentType() == Types.BYTE) {\n            return CsvSchema.ColumnType.STRING;\n        } else {\n            throw new IllegalArgumentException(\n                    \"Unsupported type information '\"\n                            + info.toString()\n                            + \"' for field '\"\n                            + fieldName\n                            + \"'.\");\n        }\n    }\n\n    /**\n     * Convert {@link LogicalType} to {@link CsvSchema.ColumnType} based on Jackson's categories.\n     */\n    private static CsvSchema.ColumnType convertType(String fieldName, LogicalType type) {\n        if (STRING_TYPE_ROOTS.contains(type.getTypeRoot())) {\n            return CsvSchema.ColumnType.STRING;\n        } else if (NUMBER_TYPE_ROOTS.contains(type.getTypeRoot())) {\n            return CsvSchema.ColumnType.NUMBER;\n        } else if (BOOLEAN_TYPE_ROOTS.contains(type.getTypeRoot())) {\n            return CsvSchema.ColumnType.BOOLEAN;","sourceCodeStart":182,"sourceCodeEnd":218,"githubUrl":"https://github.com/apache/flink/blob/2f3c205e9266cb30240eb7f4fdab15cad629a70f/flink-formats/flink-csv/src/main/java/org/apache/flink/formats/csv/CsvRowSchemaConverter.java#L182-L218","documentation":"Thrown by the legacy TypeInformation path of CsvRowSchemaConverter: while mapping a field's TypeInformation to a Jackson CsvSchema.ColumnType, the type is none of the recognized numbers/strings/booleans/object arrays/row arrays/byte arrays. It is an IllegalArgumentException at schema-construction time — the table (or DataStream type) contains a field CSV cannot represent, e.g. MAP, MULTISET, or a custom type.","triggerScenarios":"Building a CsvSchema from a RowTypeInfo that includes MapTypeInfo, MultisetTypeInfo, or arbitrary ObjectArrayTypeInfo of complex elements; PojoTypeInfo fields inside arrays at top level of the row.","commonSituations":"DataStream CSV sinks (CsvWriter via RowTypeInfo) on types richer than the CSV feature supports; migrating jobs from JSON/Arrow formats that do allow maps.","solutions":["Cast or project the offending field to a supported type before CSV conversion (e.g. serialize MAP to STRING).","Flatten nested maps/rows into top-level primitive columns.","If structured output is required, switch to a format that supports maps (json, avro)."],"exampleFix":"// before: mapField is MapTypeInfo<String,Integer> in the RowTypeInfo\n// throws at schema conversion\n\n// after: pre-convert to string\nDataStream<Row> flat = rows.map(r -> { r.setField(2, String.valueOf(r.getField(2))); return r; });","handlingStrategy":"type-guard","validationCode":"// Before building a CsvSchema from a RowTypeInfo:\nfor (TypeInformation<?> f : rowTypeInfo.getFieldTypes()) {\n    if (!isCsvSupported(f)) throw new IllegalArgumentException(\n        \"Field type not CSV-representable: \" + f);\n}\nboolean isCsvSupported(TypeInformation<?> t) {\n    return t instanceof NumericTypeInfo || t instanceof BasicTypeInfo\n        || t instanceof PrimitiveArrayTypeInfo\n        || (t instanceof BasicArrayTypeInfo && isCsvSupported(((BasicArrayTypeInfo<?,?>) t).getComponentInfo()))\n        || t instanceof RowTypeInfo;\n}","typeGuard":"static boolean isCsvSimpleType(TypeInformation<?> info) {\n    return NUMBER_TYPES.contains(info) || STRING_TYPES.contains(info)\n        || BOOLEAN_TYPES.contains(info);\n}","tryCatchPattern":null,"preventionTips":["Project to primitive/string/flat-array types before CSV","Reserve maps and multisets for json/avro sinks"],"tags":["csv","schema","type-information","unsupported-type"],"backgroundTag":null,"analyzedSha":"2f3c205e9266cb30240eb7f4fdab15cad629a70f","analyzedAt":"2026-08-14T08:48:24.518Z","schemaVersion":2},"datasetVersion":"2026-08-14T10:17:34.591Z"}