{"record":{"id":"d858494235fde338","repo":"apache/flink","slug":"field-s-is-null-but-expected-to-hold-a-key","errorCode":null,"errorMessage":"Field %s is null, but expected to hold a key.","messagePattern":"Field (.+?) is null, but expected to hold a key\\.","errorType":"exception","errorClass":"NullKeyFieldException","httpStatus":null,"severity":"error","filePath":"flink-core/src/main/java/org/apache/flink/types/Record.java","lineNumber":351,"sourceCode":"            }\n        }\n        return true;\n    }\n\n    /**\n     * Gets the fields at the given positions into an array. If at any position a field is null,\n     * then this method throws a @link NullKeyFieldException. All fields that have been successfully\n     * read until the failing read are correctly contained in the record. All other fields are not\n     * set.\n     *\n     * @param positions The positions of the fields to get.\n     * @param targets The values into which the content of the fields is put.\n     * @throws NullKeyFieldException in case of a failing field read.\n     */\n    public void getFieldsIntoCheckingNull(int[] positions, Value[] targets) {\n        for (int i = 0; i < positions.length; i++) {\n            if (!getFieldInto(positions[i], targets[i])) {\n                throw new NullKeyFieldException(i);\n            }\n        }\n    }\n\n    /**\n     * Deserializes the given object from the binary string, starting at the given position. If the\n     * deserialization asks for more that <code>limit - offset</code> bytes, than an exception is\n     * thrown.\n     *\n     * @param <T> The generic type of the value to be deserialized.\n     * @param target The object to deserialize the data into.\n     * @param offset The offset in the binary string.\n     * @param limit The limit in the binary string.\n     */\n    private <T extends Value> void deserialize(T target, int offset, int limit, int fieldNumber) {\n        final InternalDeSerializer serializer = this.serializer;\n        serializer.memory = this.binaryData;\n        serializer.position = offset;","sourceCodeStart":333,"sourceCodeEnd":369,"githubUrl":"https://github.com/apache/flink/blob/2f3c205e9266cb30240eb7f4fdab15cad629a70f/flink-core/src/main/java/org/apache/flink/types/Record.java#L333-L369","documentation":"Error \"Field %s is null, but expected to hold a key.\" thrown in apache/flink.","triggerScenarios":"Triggered at runtime when the operation fails because: Field the reported value is null, but expected to hold a key.","commonSituations":"Commonly caused by misconfiguration, missing dependencies or files, unsupported types or operations, or invalid user input leading to: Field the reported value is null, but expected to hold a key.","solutions":["Address the cause reported by the error message: Field the reported value is null, but expected to hold a key.","Verify the inputs, configuration values, and classpath/dependency setup related to this operation, then retry."],"exampleFix":"Correct the condition described (\"Field the reported value is null, but expected to hold a key.\") and rerun the job or command.","handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"2f3c205e9266cb30240eb7f4fdab15cad629a70f","analyzedAt":"2026-08-14T08:48:24.518Z","schemaVersion":2},"datasetVersion":"2026-08-14T10:17:34.591Z"}