主键自增列操作

本文主要为您介绍如何通过表格存储的Node.js SDK在创建表时添加主键自增列并写入数据。

创建表

您可以在创建表的同时添加主键自增列，示例如下：

var TableStore = require('../index.js');
var Long = TableStore.Long;
var client = require('./client');

var tableName = "autoIncTable";
var pk1 = "stringPK";
var pk2 = "autoIncPK";

function createTableWithAutoIncrementPk() {
    var createParams = {
        tableMeta: {
            tableName: tableName,
            primaryKey: [
                {
                    name: pk1,
                    type: 'STRING'
                },
                {
                    name: pk2,
                    type: 'INTEGER',
                    option: 'AUTO_INCREMENT'//自增列，指定otpion为AUTO_INCREMENT
                },
            ]
        },
        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).
        },
    };

    client.createTable(createParams, function (err, data) {
        if (err) {
            console.log('error:', err);
            return;
        }
        console.log('create table success');
    });
}

写入数据

示例如下：

var TableStore = require('../index.js');
var Long = TableStore.Long;
var client = require('./client');

var tableName = "autoIncTable";
var pk1 = "stringPK";
var pk2 = "autoIncPK";

function putRow() {
    var putParams = {
        tableName: tableName,
        condition: new TableStore.Condition(TableStore.RowExistenceExpectation.IGNORE, null),
        primaryKey: [
            { stringPK: 'pk1' },
            { autoIncPK: TableStore.PK_AUTO_INCR }
        ],
        attributeColumns: [
            { 'col1': 'col1val' }
        ],
        returnContent: { returnType: TableStore.ReturnType.Primarykey }
    };

    client.putRow(putParams, function (err, data) {
        if (err) {
            console.log('error:', err);
            return;
        }

        console.log('put row success,autoIncrement pk value:' + JSON.stringify(data.row.primaryKey));
    });

}