pglink-lite

A library for Postgresql to use ORM on NodeJS with GraphQL

Via Janden Ma

MIT LICENCE

This library is built for who uses GraphQL on NodeJS, you can use model to operate data.

Version Change Logs

• Build20190812 : Prepared version
• Build20190819 : Beta version
• Build20190826 : Fixed bugs.
• Build20190829 : Added multi insert and update functions.
• Build20190917 :
  • MultiUpdateWithConditions bug fixes.
  • Supported all update functions in model to set the fields, which need to update to current time automatically, when updated.
• Build20190919 : Supports set global parameter globalAutoSetTimeFields
• Build20190924 :
  • Changed tableName and returnTableName in Transaction to alias and returnWithAlias
  • Added Execute function in dataAccess to run a single query
  • Bug fixes
  • Optimized something
• Build20191022 : Update README.
• Build20191111 : Vast changes.
• Build20191112 :
  • Added the ability to force flatten results.
  • Added the ability to return a single record.
• Build20191114 : Corrected pg package dependency.
• Build20191120 :
  • Added connectionTimeoutMillis and idleTimeoutMillis parameters.
  • Added DataAccess.Disconnect() function (beta).
• Build20191219 : findByPk function supports multiple primary keys.
• Build20200107 : Resolved async issue for autoSetTimeFields
• Build20200116 : Added ssl
• Build20200120 : Bug fixes.
• Build20200212 : Performance improvements.
• Build20200218 : Bug fixes.
• Build20200409 : Bug fixes and performance improvements.
• Build20200421 : Added customize transaction functions
  • BeginTransaction
  • CommitTransaction
  • RollbackTransaction
• Build20200423 : Bug fixes
• Build20200427 : Optimized client connections in Transaction
• Build20200514 : Corrected sortBy option for build querying sql
• Build20200824 : Bug fixes
• Build20200917 : Corrected declaration and signature of parameters to Transaction
• Build20201010 : Upgraded pg to support PostgreSQL 13
• Build20201027 : Try to resolve ssl connections failed issue
• Build20201029 : Added preserveClient for leaving the client open for further operations in the transaction
• Build20210110 : Throw error if no valid value to insert or update.
• Build20210619 : Added safeguard in deleteByConditions
• Build20230619 : Typo fixes
• Build20230703 : Supported IS and IS NOT operators
• Build20231221 : Supported POSIX and SIMILAR TO operators

---

Installation

• npm

  npm i pglink-lite --save

• yarn

  yarn add pglink-lite --save

---

Quick Example

• Instance (core/pglink.js)

  // core/pgsqlize.js
  const { PgLink } = require('pglink-lite')
  
  const pglink = new PgLink({
    host: 'http://192.168.1.100',
    port: 5432,
    userName: 'root',
    password: '123456',
    database: 'test',
    connectionTimeoutMillis: 0,
    idleTimeoutMillis: 60000,
    globalAutoSetTimeFields: ['updatedAt'],
    ssl: true
  })
  
  module.exports.default = pglink

• Model (models/users.js)

  // models/users.js
  const pglink = require('../core/pglink')
  
  class UserModel extends pglink.Model {
    constructor() {
      super({ tableName: 'users', pkName: 'userId'})
    }
  }
  
  module.exports.default = UserModel

• Schema (schemas/users.js)

  // schemas/users.js
  // you need to install something for gql first, we use apollo-server here
  const { gql } = require('apollo-server')
  
  const typeDefs = gql`
    type User {
      userId: ID!
      userName: String
      status: Boolean
    }
  
  	input UserInsertInput {
      userName!: String
  	}
  
  	input UserEditInput {
      userId!: ID
      userName: String
      status: Boolean
  	}
  
  	type Query {
  		getUserById(userId: ID!): User
  	}
  
  	type Mutation	{
  		insertUser(user: UserInsertInput): User
  		editUser(user: UserEditInput): User
  	}
  `
  module.exports.default = typeDefs

• Resolver (resolvers/users.js)

  // resolvers/users.js
  const UserModel = require('../models/users.js')
  
  const getUserById = async (_, args) => {
    const inst = new UserModel()
    const res = await inst.findByPk({ pk: args.userId })
    return res
  }
  
  const insertUser = async (_, args) => {
    const inst = new UserModel()
    const res = await inst.insertOne({ params: args.user })
    return res
  }
  
  const editUser = async (_, args) => {
    const inst = new UserModel()
    const res = await inst.updateByPk({ params: args.user })
    return res
  }
  
  module.exports = {
    getUserById,
    insertUser,
    editUser
  }

---

Usage

• Import library package

  import { PgLink } from 'pglink-lite'
  // or
  import PgLink from 'pglink-lite'
  // or
  const { PgLink } = require('pglink-lite')
  // or
  const PgLink = require('pglink-lite')

• Instantiate PgLink

  export const pglink = new PgLink({
    host: 'http://192.168.1.100',
    port: 5432,
    userName: 'root',
    password: '123456',
    database: 'test'
  })

  • Props: object

    Key	Type	Introduction	Default value
    host	string	Postgresql server host	"localhost"
    port	number	Postgresql server port	5432
    userName	string	Postgresql server user name	"postgres"
    password	string	Postgresql server password	""(empty)
    database	string	Postgresql database name	"postgres"
    connectionMax	number	Postgresql database max connection	10
    connectionTimeoutMillis	number	Number of milliseconds to wait before timing out when connecting a new client, by default this is 0 which means no timeout	0
    idleTimeoutMillis	number	Number of milliseconds a client must sit idle in the pool and not be checked out, before it is disconnected from the backend and discarded, default is 10000 (10 seconds) - set to 0 to disable auto-disconnection of idle clients	10000
    globalAutoSetTimeFields	Array<string>	To define fields that should be automatically updated with a current timestamp	[]
    ssl	boolean	To connect to pg using ssl	false

• Inherit and declare model

  // example
  class xxxModel extends pglink.Model {
    constructor(params) {
      super({
        tableName: 'users',
        pkName: 'No',
        enumMapping: {
          sex: { MALE: 1, FAMALE: 0 },
          role: { STUDENT: 1, TEACHER: 2 }
        }
      })
    }
    // if you need rewrite inner funtions or add some functions, write here
  }

  • constructor props : object

  Key	Type	Introduction	Required
  tableName	string	the data table in postgresql you need to operate	true
  pkName	string	the name of primary key in the data table, default id	false
  enumMapping	object	to defined the key and value, key should be included in the fields, e.g. {role: {ADMIN: 0, USER: 1}}	false

  • inner properties or functions

    1. dataAccess

       • Introduction

         A data table operator (CRUD)

       • see the details below

    2. findAll

       • Introduction

         A function for querying all rows from one table

       • Parameters

         { options: object, default { sortBy: undefined, limit: undefined, offset: undefined }

         preserveClient: boolean

         callback: function }

       • Returns

         (Promise) All rows data or error

    3. findByPk

       • Introduction

         A function for querying by primary key

       • Parameters

         {

         pkValue: string | number | object

         • if multiple primary keys, should use object, e.g. {id: 1, cid: 2}

         selectFields: string, default *

         callback: function

         preserveClient: boolean

         }

       • Returns

         (Promise) One row data or error

    4. findByConditions

       • Introduction

         A function for querying by conditions

       • Parameters

         { whereClause: string. (e.g. ' name = "Tim" ')

         selectFields: string, default *

         options: object, default { sortBy: undefined, limit: undefined, offset: undefined }

         preserveClient: boolean

         callback: function }

       • Returns

         (Promise) Some rows data or error

    5. InsertOne

       • Introduction

         A function for inserting one row to a table

       • Parameters

         {

         params: object. (data from resolver)

         callback: function

         client: object

         preserveClient: boolean

         }

       • Returns

         (Promise) Inserted row data or errors

    6. multiInsert

       • Introduction

         A function for inserting multi rows to a table

       • Parameters

         {

         items: Array<object>. (data from resolver)

         forceFlat?: boolean (whether or not to force results into a single array)

         callback: function

         client: object

         preserveClient: boolean

         }

       • Returns

         (Promise) Inserted rows data or errors

    7. updateByPk

       • Introduction

         A function for updating by primary key

       • Parameters

         { params: object. (data from resolver, have to include pkName and pkValue)

         autoSetTimeFields: Those fields need to set time automatically, should be included in items

         callback: function

         client: object

         preserveClient: boolean }

       • Returns

         (Promise) updated row data or errors

    8. updateByConditions

       • Introduction

         A function for updating by conditions

       • Parameters

         { params: object. (data from resolver)

         whereClause: string. (e.g. ' name = "Tim" ')

         autoSetTimeFields: Those fields need to set time automatically, should be included in items

         callback: function

         client: object

         preserveClient: boolean }

       • Returns

         (Promise) updated rows data or errors

    9. multiUpdateWithConditions

       • Introduction

         A function for multi updating by conditions

       • Parameters

         { items: Array<object>. (data from resolver)

         whereClause: string with replacements. (e.g. ' company = $1 ')

         replacementFields: Array<string> (e.g. ['company'])

         autoSetTimeFields: Those fields need to set time automatically, should be included in items

         forceFlat?: boolean (if true, forces results into a single array)

         callback: function

         client: object

         preserveClient: boolean }

       • Returns

         (Promise) Updated rows data or errors

    10. deleteByConditions

        • Introduction

          A function for deleting by conditions

        • Parameters

          { whereClause: string. (e.g. ' "companyId" = 1001 ')

          returnSingleRecord?: boolean (if true, returns just one record)

          callback: function

          client: object

          preserveClient: boolean }

        • Returns

          (Promise) Deleted rows data or errors

    11. encodeFromEnum

        • Introduction

          A function for encoding the enum to integer value

        • Parameters

          data: object | Array. (input data)

        • Returns

          (Object) Same structure of input data, with encoded enum

    12. decodeToEnum

        • Introduction

          A function for decoding the enum from integer value

        • Parameters

          data: object | Array. (output data)

        • Returns

          (Object) Same structure of output data, with decoded enum

  • dataAccess functions

    1. Execute

       • Introduction

         to run a single and simple sql

       • Parameters:

         • sql: string

       • Returns

         reponse from database

       • Example:

           const sqlStatement = `SQL STATEMENT GOES HERE`
           const res = await this.dataAccess.Execute(sqlStatement);

    2. Transaction

       • Introduction

         core function with transaction

       • Parameters:

          args: {
             params: Array<{
             sql: string
             replacements?: Array<any>
             alias?: string // to distinguish responses
             }>
           client?: object
           returnWithAlias?: boolean, // if true, return res with alias
           returnSingleRecord?: boolean,
           forceFlat?: boolean,
           preserveClient?: boolean // Skips committing the operation, leaving the client open for further operations in the transaction
          },
          transaction: Function // callback function or Transaction

       • Returns

         reponse from database

    3. GenerateInsertSQL

       • Introduction

         generate insert sql object

       • Parameters

         params: object, //data from resolver, includes inserted fields and values
         tableName: string //name of inserted table

       • Returns

         {
           sql: string
           replacement: Array<any>
           tableName: string
         }

    4. GenerateMultiInsertSQL

       • Introduction

         generate bulk insert sql object

       • Parameters

         insertFields: Array<string>,
         params: object, //data from resolver, includes inserted fields and values
         tableName: string //name of inserted table

       • Returns

         {
           sql: string
           replacement: Array<any>
           tableName: string
         }

    5. GenerateUpdateSQL

       • Introduction

         generate update sql object

       • Parameters

         {
         	/** an object includes the fields and values you want to update */
           params: object
           /** the name of table */
           tableName: string
           /** e.g. "employeeId" = '123' */
           whereClause?: string
           /** the name of primary key, default 'id' */
           pkName?: string
           /** those fields need to set time automatically, default value is from globalAutoSetTimeFields. We will check whether fields included in the table, if not, skip */
           autoSetTimeFields?: Array<string>
         }

       • Returns

         {
           sql: string
           replacement: Array<any>
           tableName: string
         }

    6. InsertExecutor

       • Introduction

         execute insert sql

       • Parameters

         params: object, //data from resolver, includes inserted fields and values
         tableName: string, //name of inserted table
         callback?: function, //function to run before committing the transaction
         client?: object //the pg client to be used for the transaction
         preserveClient?: boolean // skips comitting the client if true

       • Returns

         response from database

    7. MultiInsertToOneTableExecutor

       • Introduction

         execute insert sqls to one table

       • Parameters

         insertFields: Array<string>,
         params: object, //data from resolver, includes inserted fields and values
         tableName: string, //name of inserted table
         callback?: function, //function to run before committing the transaction
         client?: object //the pg client to be used for the transaction
         preserveClient?: boolean // skips comitting the client if true

       • Returns

         response from database

    8. MultiInsertExecutor

       • Introduction

         execute insert sqls to deferent tables

       • Parameters

         Array<
         {
           params: object, //data from resolver, includes inserted fields and values
           tableName: string //name of inserted table
         }>,
         forceFlat?: boolean, //if true, forces results into one array
         callback?: function, //function to run before committing the transaction
         client?: object //the pg client to be used for the transaction
         preserveClient?: boolean // skips comitting the client if true

       • Returns

         response from database

    9. UpdateByPkExecutor

       • Introduction

         execute update sql by primary key

       • Parameters

         params: object, //data from resolver, includes updated fields and values
         tableName: string, //name of inserted table
         pkName?: string, //the name of primary key
         autoSetTimeFields?: Array<string> ,//those fields need to set time automatically
         callback?: function, //function to run before committing the transaction
         client?: object //the pg client to be used for the transaction
         preserveClient?: boolean // skips comitting the client if true

       • Returns

         response from database

    10. UpdateExecutor

        • Introduction

          execute update sql by conditions

        • Parameters

          params: object, //data from resolver, includes updated fields and values
          tableName: string, //name of inserted table
          whereClause?: string, //e.g. "employeeId" = '123'
          autoSetTimeFields?: Array<string>, //those fields need to set time automatically
          callback?: function, //function to run before committing the transaction
          client?: object //the pg client to be used for the transaction
          preserveClient?: boolean // skips comitting the client if true

        • Returns

          response from database

    11. MultiUpdateExecutor

        • Introduction

          execute bulk update sqls by conditions

        • Parameters

          Array<
            {
            params: object, //data from resolver, includes updated fields and values
              tableName: string, //name of inserted table
              whereClause?: string //e.g. "employeeId" = '123'
              pkName: string, //the name of primary key
              autoSetTimeFields?: Array<string>, //those fields need to set time automatically
              client?: object //the pg client to be used for the transaction
            }>,
            forceFlat?: boolean //if true, forces results into a single array
            callback?: function //function to run before committing the transaction
            preserveClient?: boolean // skips comitting the client if true

        • Returns

          response from database

    12. DeleteExecutor

        • Introduction

          execute delete sql by conditions

        • Parameters

          tableName: string, //name of inserted table
          whereClause?: string, //e.g. "employeeId" = '123'
          returnSingleRecord?: boolean,//if true, returns one record instead of array
          callback?: function, //function to run before committing the transaction
          client?: object //the pg client to be used for the transaction
          preserveClient?: boolean // skips comitting the client if true

        • Returns

        response from database

    13. SingleQueryExecutor

        • Introduction

          execute query sql

        • Parameters

          {
             /** the name of table */
           	tableName: string
             /** e.g. "employeeId" = '123' */
             whereClause: string
             /** the fields what you want to select, default * */
             selectFields?: string
             /** the field name for sorting, e.g.: [{field: 'id', sequence:'DESC'}] */
             sortBy?: Array<{ field: String; sequence?: 'ASC' | 'DESC' }>
             /** to limit the count of rows you want to query */
             limit?: number
             /** how many rows you want to skip */
             offset?: number,
            /** if true, return a single record instead of an array */
             returnSingleRecord?: boolean,
             client?: object //the pg client to be used for the transaction
             preserveClient?: boolean // skips comitting the client if true
          }

        • Returns

          response from database

    14. Disconnect [Beta Function]

        • Introduction

          It will drain the pool of all active clients, disconnect them, and shut down any internal timers in the pool. It is common to call this at the end of a script using the pool or when your process is attempting to shut down cleanly.