{"record":{"id":"8f2e3c34b97395bc","repo":"apache/seatunnel","slug":"unsupported-databend-type-fallback-to-string","errorCode":null,"errorMessage":"Unsupported Databend type: {}, fallback to STRING type","messagePattern":"Unsupported Databend type: (.+?), fallback to STRING type","errorType":"console","errorClass":null,"httpStatus":null,"severity":"warning","filePath":"seatunnel-connectors-v2/connector-databend/src/main/java/org/apache/seatunnel/connectors/seatunnel/databend/catalog/DatabendCatalog.java","lineNumber":504,"sourceCode":"            case \"DOUBLE\":\n            case \"FLOAT64\":\n                return BasicType.DOUBLE_TYPE;\n            case \"DECIMAL\":\n                return new DecimalType(columnSize, decimalDigits);\n            case \"STRING\":\n            case \"VARCHAR\":\n            case \"CHAR\":\n            case \"TEXT\":\n                return BasicType.STRING_TYPE;\n            case \"DATE\":\n                return LocalTimeType.LOCAL_DATE_TYPE;\n            case \"TIMESTAMP\":\n                return LocalTimeType.LOCAL_DATE_TIME_TYPE;\n            case \"VARBINARY\":\n            case \"BINARY\":\n                return BasicType.BYTE_TYPE;\n            default:\n                log.warn(\"Unsupported Databend type: {}, fallback to STRING type\", typeName);\n                return BasicType.STRING_TYPE;\n        }\n    }\n\n    private Connection getConnection() throws SQLException {\n        return DatabendUtil.createConnection(this.readonlyConfig);\n    }\n\n    private void checkOpen() {\n        if (!isOpened) {\n            throw new DatabendConnectorException(\n                    DatabendConnectorErrorCode.ILLEGAL_STATE,\n                    \"Databend catalog is not opened. Please call open() first.\");\n        }\n    }\n}\n","sourceCodeStart":486,"sourceCodeEnd":521,"githubUrl":"https://github.com/apache/seatunnel/blob/cf67b549a7a6c35fa0beb12d83c62892427ea919/seatunnel-connectors-v2/connector-databend/src/main/java/org/apache/seatunnel/connectors/seatunnel/databend/catalog/DatabendCatalog.java#L486-L521","documentation":"DatabendCatalog.convertDatabendType maps Databend SQL type names to SeaTunnel types. Unknown/unmapped type names hit the default branch: the warning is logged and STRING is used as fallback. The catalog continues, but the column type is widened/approximated, potentially causing precision loss or wrong downstream types.","triggerScenarios":"A table contains a Databend column type that has no case in convertDatabendType's switch (e.g. newer Databend types like GEOGRAPHY, VARIANT, JSON, or bitmap types).","commonSituations":"Reading Databend semi-structured columns (VARIANT/OBJECT/ARRAY); Databend version newer than the connector's supported type map; user-defined domain types surfaced through JDBC metadata.","solutions":["Identify the reported typeName and cast that column to a supported type in your query/view (e.g. CAST(col AS VARCHAR))","Upgrade the SeaTunnel connector version to one that maps the new Databend types","If the type should map to something specific, contribute/patch convertDatabendType to add a case for it"],"exampleFix":"// before\nSELECT id, variant_col FROM t;\n// after\nSELECT id, CAST(variant_col AS VARCHAR) AS variant_col FROM t;","handlingStrategy":"fallback","validationCode":"// Check table columns for unmapped types before sync\nSELECT data_type FROM information_schema.columns\nWHERE table_schema=? AND table_name=?;\n// Compare each data_type against supported mapping list","typeGuard":null,"tryCatchPattern":null,"preventionTips":["Avoid semi-structured Databend types (VARIANT/JSON) in synced tables, or cast them to VARCHAR","Pin connector versions tested against your Databell/Databend server version","Review fallback warnings at catalog initialization and adjust schema"],"tags":["databend","type-mapping","fallback","catalog"],"backgroundTag":"unsupported-dtype","analyzedSha":"cf67b549a7a6c35fa0beb12d83c62892427ea919","analyzedAt":"2026-09-10T21:44:55.265Z","contentChangedAt":"2026-09-10T21:44:55.265Z","schemaVersion":2},"datasetVersion":"2026-09-14T11:17:12.474Z"}