[[["容易理解","easyToUnderstand","thumb-up"],["確實解決了我的問題","solvedMyProblem","thumb-up"],["其他","otherUp","thumb-up"]],[["難以理解","hardToUnderstand","thumb-down"],["資訊或程式碼範例有誤","incorrectInformationOrSampleCode","thumb-down"],["缺少我需要的資訊/範例","missingTheInformationSamplesINeed","thumb-down"],["翻譯問題","translationIssue","thumb-down"],["其他","otherDown","thumb-down"]],["上次更新時間：2025-09-04 (世界標準時間)。"],[[["\u003cp\u003eThe \u003ccode\u003ecbt\u003c/code\u003e CLI can format complex data types stored in Bigtable rows for improved readability when using \u003ccode\u003ecbt read\u003c/code\u003e or \u003ccode\u003ecbt lookup\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eFormatting is defined in a YAML file, specifying data types and encodings for columns or column families, which is then passed to the \u003ccode\u003ecbt\u003c/code\u003e CLI using the \u003ccode\u003eformat-file\u003c/code\u003e argument.\u003c/p\u003e\n"],["\u003cp\u003eYAML formatting can include protocol buffer definitions and paths, allowing for the decoding and display of protobuf messages stored in Bigtable.\u003c/p\u003e\n"],["\u003cp\u003eSupported data types for formatting include hexadecimal, big-endian, little-endian, protocol buffer, and JSON, each with specific formatting values for the YAML file.\u003c/p\u003e\n"],["\u003cp\u003eA default formatting can be applied to an entire table, or specific column family in the YAML file, including default type, and encoding, with the possibility to override these at the column level.\u003c/p\u003e\n"]]],[],null,["# Format output from the cbt CLI\n\nFormat output from the\ncbt CLI\n==============================\n\nThis document describes how to format specific types of data stored in\nBigtable rows when displayed by the\n`cbt` CLI\n.\n\nExamples of formatting\n----------------------\n\nStarting with version 0.12.0, the\n`cbt` CLI\ncan format\n[certain complex types](#data-types) of data stored in table rows.\nWhen you use the `cbt read` or `cbt lookup` command, the\n`cbt` CLI\ncan\n\"pretty print\" values stored in the rows.\n\nThe following example shows data output from the\n`cbt` CLI\nwithout\nformatting. \n\n ----------------------------------------\n r1\n fam1:col1 @ 2022/03/09-11:19:45.966000\n \"\\n\\x05Brave\\x10\\x02\"\n fam1:col2 @ 2022/03/14-11:17:20.014000\n \"{\\\"name\\\": \\\"Brave\\\", \\\"age\\\": 2}\"\n\nThe following example shows data output from the\n`cbt` CLI\nwith\nformatting. \n\n r1\n fam1:col1 @ 2022/03/09-11:19:45.966000\n name: \"Brave\"\n age: 2\n fam1:col2 @ 2022/03/14-11:17:20.014000\n age: 2.00\n name: \"Brave\"\n\nPrint rows with formatting\n--------------------------\n\nTo format a column or column family, you must provide a YAML file that\nspecifies the formatting for that column. When you call `cbt lookup` or\n`cbt read`, you pass in the path to the YAML file with the `format-file`\nargument. The following snippet shows an example of calling `cbt lookup` with\nthe `format-file` argument supplied. \n\n cbt lookup my-table r1 format-file=/path/to/formatting.yml\n\n### Define column data formats in YAML\n\nThe formatting YAML file must connect the column names or column family names\nwith the data types stored within them. The following snippet shows an example\nof a YAML formatting file. \n\n protocol_buffer_definitions:\n - cat.proto\n protocol_buffer_paths:\n - testdata/\n\n\n columns:\n col1:\n encoding: ProtocolBuffer\n type: Cat\n\n col2:\n encoding: json\n\nThe following snippet shows the contents of 'cat.proto'. \n\n syntax = \"proto3\";\n package cats;\n\n option go_package = \"github.com/protocolbuffers/protobuf/examples/go/tutorialpb\";\n\n message Cat {\n string name = 1;\n int32 age = 2;\n }\n\nLooking at the example:\n\n- The `protocol_buffer_definitions` field provides a list of .proto files that can contain protocol buffer message types to use for decoding protobuf data.\n- The `protocol_buffer_paths` field provides a list of local paths that can contain .proto files for decoding protocol buffer types. You do not need to specify the locations of standard protocol buffer imports, such as messages in the `google/protobuf` package.\n- The `columns` field contains a list of column names with the corresponding\n data types for each column:\n\n - The `protobuf` column has its `encoding` set to \"ProtocolBuffer\" and its `type` is set to 'Cat'. The `cbt` CLI interprets and formats all values stored in this column as a `Cat` proto message type. The type must correspond to a message type defined in one of the .proto files provided for the `protocol_buffer_definition` field.\n - The `json` column has its `encoding` field set to \"json\". The `cbt` interprets and formats all values stored in this column as a JSON structure.\n\nOther fields that you can provide:\n\n- `default_encoding`: This field defines a default formatting for all all columns in a table or all columns in a column family.\n- `default_type`: This field defines a default data type for protocol buffer, big-endian, and little-endian encoded columns.\n- `families`: This field defines encodings and types for all columns within\n a column family. You can provide a `default_encoding` and `default_type`\n for a column family. You can also override these encodings at the column\n level by providing a `columns` field that lists columns by name with the\n appropriate encoding and data types, as shown in the following snippet:\n\n families:\n family1:\n default_encoding: BigEndian\n default_type: INT64\n columns:\n address:\n encoding: PROTO\n type: tutorial.Person\n\nSupported data types\n--------------------\n\nThe\n`cbt` CLI\nsupports formatting for several complex data types. The following\ntable lists the supported data types and strings to provide in the YAML file\nfor each of the list types. String values are not case-sensitive.\n\n**Table 1.** Data types supported for formatting in `cbt` output.\n\n- The hexadecimal encoding is type agnostic. Data are displayed as a raw hexadecimal representation of the stored data.\n- The available types for the big-endian and little-endian encodings are `int8`, `int16`, `int32`, `int64`, `uint8`, `uint16`, `uint32`, `uint64`, `float32`, and `float64`. Stored data length must be a multiple of the type sized, in bytes. Data are displayed as scalars if the stored length matches the type size, or as arrays otherwise. Types names are not case-sensitive.\n- The types given for the *protocol-buffer* encoding must match message types defined in provided protocol-buffer definition files. The types are not case-sensitive. If no type is specified, it defaults to the column name for the column data being displayed.\n- The formatting values for YAML are not case-sensitive."]]
