本文主要为您介绍如何通过表格存储的Node.js SDK创建全局二级索引、读取全局二级索引表中的数据、删除全局二级索引。

创建全局二级索引

  • 创建主表同时创建全局二级索引
    示例如下： 
    var client = require('./client');
var TableStore = require('../index.js');

var params = {
  tableMeta: {
    tableName: 'sdkGlobalTest',
    primaryKey: [
      {
        name: 'pk1',
        type: TableStore.PrimaryKeyType.INTEGER
      },
      {
        name: 'pk2',
        type: TableStore.PrimaryKeyType.INTEGER
      }
    ],
    definedColumn: [
      {
        "name": "col1",
        "type": TableStore.DefinedColumnType.DCT_INTEGER
      },
      {
        "name": "col2",
        "type": TableStore.DefinedColumnType.DCT_INTEGER
      }
    ],
  },
  reservedThroughput: {
    capacityUnit: {
      read: 0,
      write: 0
    }
  },
  tableOptions: {
    timeToLive: -1,// 数据的过期时间，单位秒， -1代表永不过期。 假如设置过期时间为一年，即为 365 * 24 * 3600
    maxVersions: 1// 保存的最大版本数，设置为1即代表每列上最多保存一个版本（保存最新的版本）
  },
  streamSpecification: {
    enableStream: false, //globalIndex不支持开启Stream
  },
  indexMetas: [
    {
      name: "sdkIndex1",
      primaryKey: ["pk2"],
      definedColumn: ["col1", "col2"]
    },
    {
      name: "sdkIndex2",
      primaryKey: ["col1"],
      definedColumn: ["col2"]
    }
  ]
};

client.createTable(params, function (err, data) {
  if (err) {
    console.log('error:', err);
    return;
  }
  console.log('success:', data);
});
  • 单独创建全局二级索引
    您可以在一张已经存在的主表上创建全局二级索引表，示例如下： 
    var client = require('./client');
var TableStore = require('../index.js');

client.createIndex({
    mainTableName: "sdkGlobalTest",
    indexMeta: {
        name: "sdkIndex2",
        primaryKey: ["col1"],
        definedColumn: ["col2"],
        includeBaseData: false,
        indexUpdateMode: TableStore.IndexUpdateMode.IUM_ASYNC_INDEX,//默认增量
        indexType: TableStore.IndexType.IT_GLOBAL_INDEX,//IT_GLOBAL_INDEX
    }
}, function (err, data) {
    if (err) {
        console.log('error:', err);
        return;
    }
    console.log('success:', JSON.stringify(data, null, 2));
});

删除全局二级索引

您可以删除主表上的全局二级索引表，示例如下： 
var client = require('./client');

client.dropIndex({
  mainTableName: "sdkGlobalTest",
  indexName: "sdkIndex1"
}, function (err, data) {
  if (err) {
    console.log('error:', err);
    return;
  }
  console.log('success:', JSON.stringify(data, null, 2));
});

读取二级索引表中的数据

示例如下：
  • 单行读取全局二级索引表 
    var TableStore = require('../index.js');
var Long = TableStore.Long;
var client = require('./client');

var params = {
  tableName: "index1",
  primaryKey: [ {'pk2': Long.fromNumber(2)}, {'pk1': Long.fromNumber(1)}]
};

client.getRow(params, function (err, data) {
  if (err) {
    console.log('error:', err);
    return;
  }
  console.log('success:', JSON.stringify(data, null, 2));
});
  • 范围读取全局二级索引表 
    var TableStore = require('../index.js');
var Long = TableStore.Long;
var client = require('./client');

var params = {
  tableName: "index1",
  primaryKey: [ {'pk2': Long.fromNumber(2)}, {'pk1': Long.fromNumber(1)}]
};

client.getRow(params, function (err, data) {
  if (err) {
    console.log('error:', err);
    return;
  }
  console.log('success:', JSON.stringify(data, null, 2));
});