SQLServer module

SQLServer components for Node.js / ES2017. This module is a part of the Pip.Services polyglot microservices toolkit.

Packages

The module contains the following packages:

  • Build - a standard factory for constructing components
  • Connect - instruments for configuring connections to the database.
  • Persistence - abstract classes for working with the database that can be used for connecting to collections and performing basic CRUD operations

Use

Install the NPM package as

npm install pip-services3-sqlserver-nodex --save

As an example, lets create persistence for the following data object.

import { IIdentifiable } from 'pip-services3-commons-nodex';

export class MyObject implements IIdentifiable {
  public id: string;
  public key: string;
  public value: number;
}

The persistence component shall implement the following interface with a basic set of CRUD operations.

export interface IMyPersistence {
  getPageByFilter(correlationId: string, filter: FilterParams, paging: PagingParams,
    callback: (err: any, page: DataPage<MyObject>) => void): void;
    
  getOneById(correlationId: string, id: string, callback: (err: any, item: MyObject) => void): void;
    
  getOneByKey(correlationId: string, key: string, callback: (err: any, item: MyObject) => void): void;
    
  create(correlationId: string, item: MyObject, callback?: (err: any, item: MyObject) => void): void;
    
  update(correlationId: string, item: MyObject, callback?: (err: any, item: MyObject) => void): void;
    
  deleteById(correlationId: string, id: string, callback?: (err: any, item: MyObject) => void): void;
}

To implement sql server persistence component you shall inherit IdentifiableSqlServerPersistence. Most CRUD operations will come from the base class. You only need to override getPageByFilter method with a custom filter function. And implement a getOneByKey custom persistence method that doesn’t exist in the base class.

import { IdentifiableSqlServerPersistence } from 'pip-services3-sqlserver-nodex';

export class MySqlServerPersistence extends IdentifableSqlServerPersistence {
  public constructor() {
    super("myobjects");
    this.ensureSchema("CREATE TABLE [myobjects] ([id] VARCHAR(32) PRIMARY KEY, [key] VARCHAR(50), [value] NVARCHAR(255)");
    this.ensureIndex("myobjects_key", { '[key]': 1 }, { unique: true });
  }

  private composeFilter(filter: FilterParams): any {
    filter = filter || new FilterParams();
    
    let criteria = [];

    let id = filter.getAsNullableString('id');
    if (id != null)
        criteria.push("[id]='" + id + "'");

    let tempIds = filter.getAsNullableString("ids");
    if (tempIds != null) {
        let ids = tempIds.split(",");
        filters.push("[id] IN ('" + ids.join("','") + "')");
    }

    let key = filter.getAsNullableString("key");
    if (key != null)
        criteria.push("[key]='" + key + "'");

    return criteria.length > 0 ? criteria.join(" AND ") : null;
  }
  
  public getPageByFilter(correlationId: string, filter: FilterParams, paging: PagingParams,
    callback: (err: any, page: DataPage<MyObject>) => void): void {
    super.getPageByFilter(correlationId, this.composeFilter(filter), paging, "id", null, callback);
  }  
  
  public getOneByKey(correlationId: string, key: string,
    callback: (err: any, item: MyObject) => void): void {
    
    let query = "SELECT * FROM " + this.quoteIdentifier(this._tableName) + " WHERE [key]=@1";
    let params = [ key ];

    let request = this.createRequest(params);
    request.query(query, (err, result) => {
      err = err || null;

      let item = result && result.recordset ? result.recordset[0] || null : null; 

      if (item == null)
        this._logger.trace(correlationId, "Nothing found from %s with key = %s", this._tableName, key);
      else
        this._logger.trace(correlationId, "Retrieved from %s with key = %s", this._tableName, key);

      item = this.convertToPublic(item);
      callback(err, item);
    });
  }

}

Alternatively you can store data in non-relational format using IdentificableJsonSqlServerPersistence. It stores data in tables with two columns - id with unique object id and data with object data serialized as JSON. To access data fields you shall use JSON_VALUE([data],'$.field') expression.

import { IdentifiableJsonSqlServerPersistence } from 'pip-services3-sqlserver-nodex';

export class MySqlServerPersistence extends IdentifableJsonSqlServerPersistence {
  public constructor() {
    super("myobjects");
    this.ensureTable();
    this.autoCreateObject("ALTER TABLE [myobjects] ADD [data_key] AS JSON_VALUE([data],'$.key')")
    this.ensureIndex('myobjects_key', { data_key: 1 }, { unique: true });
  }

  private composeFilter(filter: FilterParams): any {
    filter = filter || new FilterParams();
    
    let criteria = [];

    let id = filter.getAsNullableString('id');
    if (id != null)
        criteria.push("JSON_VALUE([data],'$.id')='" + id + "'");

    let tempIds = filter.getAsNullableString("ids");
    if (tempIds != null) {
        let ids = tempIds.split(",");
        filters.push("JSON_VALUE([data],'$.id') IN ('" + ids.join("','") + "')");
    }

    let key = filter.getAsNullableString("key");
    if (key != null)
        criteria.push("JSON_VALUE([data],'$.key')='" + key + "'");

    return criteria.length > 0 ? criteria.join(" AND ") : null;
  }
  
  public getPageByFilter(correlationId: string, filter: FilterParams, paging: PagingParams,
    callback: (err: any, page: DataPage<MyObject>) => void): void {
    super.getPageByFilter(correlationId, this.composeFilter(filter), paging, "id", null, callback);
  }  
  
  public getOneByKey(correlationId: string, key: string,
    callback: (err: any, item: MyObject) => void): void {
    
    let query = "SELECT * FROM " + this.quoteIdentifier(this._tableName) + " WHERE JSON_VALUE([data],'$.key')=@1";
    let params = [ key ];

    let request = this.createRequest(params);
    request.query(query, (err, result) => {
      err = err || null;

      let item = result && result.recordset ? result.recordset[0] || null : null; 

      if (item == null)
        this._logger.trace(correlationId, "Nothing found from %s with key = %s", this._tableName, key);
      else
        this._logger.trace(correlationId, "Retrieved from %s with key = %s", this._tableName, key);

      item = this.convertToPublic(item);
      callback(err, item);
    });
  }

}

Configuration for your microservice that includes sqlserver persistence may look the following way.

...
{{#if SQLSERVER_ENABLED}}
- descriptor: pip-services:connection:sqlserver:con1:1.0
  table: {{SQLSERVER_TABLE}}{{#unless SQLSERVER_TABLE}}myobjects{{/unless}}
  connection:
    uri: {{{SQLSERVER_SERVICE_URI}}}
    host: {{{SQLSERVER_SERVICE_HOST}}}{{#unless SQLSERVER_SERVICE_HOST}}localhost{{/unless}}
    port: {{SQLSERVER_SERVICE_PORT}}{{#unless SQLSERVER_SERVICE_PORT}}1433{{/unless}}
    database: {{SQLSERVER_DB}}{{#unless SQLSERVER_DB}}app{{/unless}}
  credential:
    username: {{SQLSERVER_USER}}
    password: {{SQLSERVER_PASS}}
    
- descriptor: myservice:persistence:sqlserver:default:1.0
  dependencies:
    connection: pip-services:connection:sqlserver:con1:1.0
{{/if}}
...