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Tablet Interfaces Guide

Overview

IoTDB Node.js client provides two distinct tablet interfaces for tree and table models, matching the design of C# and Java clients.

TreeTablet - For Tree/Timeseries Model

Used with Session and SessionPool for timeseries data.

Interface

interfaceTreeTablet{deviceId: string;// Full device path, e.g., "root.sg.device1"measurements: string[];// Sensor names, e.g., ["temperature", "humidity"]dataTypes: number[];// Data type for each measurementtimestamps: number[];// Timestamps in millisecondsvalues: any[][];// Values array [rows][columns]}

Example

awaitsession.insertTreeTablet({deviceId: 'root.factory.workshop1.device1',measurements: ['temperature','humidity','pressure'],dataTypes: [TSDataType.FLOAT,TSDataType.FLOAT,TSDataType.DOUBLE],timestamps: [Date.now(),Date.now()+1000,Date.now()+2000],values: [[25.5,60.0,101.3],[26.0,61.5,101.2],[26.5,62.0,101.1],],});

TableTablet - For Table/Relational Model

Used with TableSessionPool for relational data.

Interface

interfaceTableTablet{tableName: string;// Table namecolumnNames: string[];// All column names including time, tags, fieldscolumnTypes: number[];// Data type for each columncolumnCategories: ColumnCategory[];// Category for each columntimestamps: number[];// Timestamps in millisecondsvalues: any[][];// Values array [rows][columns]}

ColumnCategory Enum

Matches C# and Java client definitions:

enumColumnCategory{TAG=0,// Tag column - indexed for WHERE clause filteringFIELD=1,// Field column - measurement valuesATTRIBUTE=2,// Attribute column - metadata not indexedTIME=3,// Time column (reserved for internal use only)}

Important: TIME is reserved for internal use. Do not use it in columnCategories arrays. Timestamps are handled separately via the timestamps array.

Example

awaittablePool.insertTablet({tableName: 'sensor_data',columnNames: ['device_id','model','temperature','humidity'],columnTypes: [TSDataType.STRING,TSDataType.STRING,TSDataType.FLOAT,TSDataType.FLOAT],columnCategories: [ColumnCategory.TAG,// device_id - indexed tagColumnCategory.ATTRIBUTE,// model - metadataColumnCategory.FIELD,// temperature - measurementColumnCategory.FIELD// humidity - measurement],timestamps: [Date.now(),Date.now()+1000],values: [['device_001','model_A',25.5,60.0],['device_001','model_A',26.0,61.5],],});

Column Categories Explained

TAG

  • Used to identify devices or entities
  • Typically indexed for fast lookups
  • Example: device_id, sensor_id

FIELD

  • Actual measurement values
  • The data being recorded
  • Example: temperature, humidity, pressure

ATTRIBUTE

  • Metadata about the device or measurement
  • Static or slowly changing values
  • Example: model, location, version

TIME

  • Timestamp column
  • Only one TIME column per table
  • Always required

Migration from Old Tablet Interface

Before (Deprecated)

awaitsession.insertTablet({deviceId: 'root.test.device1',measurements: ['sensor1'],dataTypes: [TSDataType.FLOAT],timestamps: [Date.now()],values: [[25.5]],});

After (Tree Model)

awaitsession.insertTreeTablet({deviceId: 'root.test.device1',measurements: ['sensor1'],dataTypes: [TSDataType.FLOAT],timestamps: [Date.now()],values: [[25.5]],});

After (Table Model)

awaittablePool.insertTablet({tableName: 'my_table',columnNames: ['device_id','sensor1'],columnTypes: [TSDataType.STRING,TSDataType.FLOAT],columnCategories: [ColumnCategory.TAG,ColumnCategory.FIELD],timestamps: [Date.now()],values: [['device_001',25.5]],});

Backward Compatibility

The old insertTablet() method is still available but deprecated. It internally calls insertTreeTablet() for backward compatibility.

See Also