Trenutno je REST API postao standard za razvoj web aplikacija, dopuštajući da se razvoj podijeli na neovisne dijelove. Za UI se trenutno koriste razni popularni okviri kao što su Angular, React, Vue i drugi. Pozadinski programeri mogu birati između širokog spektra jezika i okvira. Danas bih želio razgovarati o takvom okviru kao što je NestJS. Mi smo u TestMace Aktivno ga koristimo za interne projekte. Korištenje gnijezda i paketa @nestjsx/crud, izradit ćemo jednostavnu CRUD aplikaciju.

Zašto NestJS

Nedavno se u JavaScript zajednici pojavilo dosta pozadinskih okvira. A ako u smislu funkcionalnosti pružaju slične mogućnosti kao Nest, onda u jednoj stvari definitivno pobjeđuje - to je arhitektura. Sljedeće NestJS značajke omogućuju vam stvaranje industrijskih aplikacija i skaliranje razvoja na velike timove:

koristeći TypeScript kao glavni razvojni jezik. Iako NestJS podržava JavaScript, neke funkcije možda neće raditi, posebno ako govorimo o paketima trećih strana;
prisutnost DI spremnika, koji vam omogućuje stvaranje labavo povezanih komponenti;
Funkcionalnost samog okvira podijeljena je na neovisne međusobno zamjenjive komponente. Na primjer, ispod haube kao okvir može se koristiti kao izrazitiI ubrzati, za rad s bazom podataka, gnijezdo izvan kutije nudi vezanja za typeorm, mungos, nastaviti;
NestJS ne ovisi o platformi i podržava REST, GraphQL, Websockets, gRPC itd.

Sam framework inspiriran je Angular frontend frameworkom i konceptualno ima mnogo toga zajedničkog s njim.

Instaliranje NestJS-a i implementacija projekta

Nest sadrži paket gnijezdo/cli, koji vam omogućuje brzu implementaciju osnovnog aplikacijskog okvira. Instalirajmo ovaj paket globalno:

npm install --global @nest/cli

Nakon instalacije generirat ćemo osnovni okvir naše aplikacije s nazivom gnijezdo-rest. To se radi pomoću naredbe nest new nest-rest.

gnijezdo novo gnijezdo-rest

dmitrii@dmitrii-HP-ZBook-17-G3:~/projects $ nest new nest-rest
  We will scaffold your app in a few seconds..

CREATE /nest-rest/.prettierrc (51 bytes)
CREATE /nest-rest/README.md (3370 bytes)
CREATE /nest-rest/nest-cli.json (84 bytes)
CREATE /nest-rest/nodemon-debug.json (163 bytes)
CREATE /nest-rest/nodemon.json (67 bytes)
CREATE /nest-rest/package.json (1805 bytes)
CREATE /nest-rest/tsconfig.build.json (97 bytes)
CREATE /nest-rest/tsconfig.json (325 bytes)
CREATE /nest-rest/tslint.json (426 bytes)
CREATE /nest-rest/src/app.controller.spec.ts (617 bytes)
CREATE /nest-rest/src/app.controller.ts (274 bytes)
CREATE /nest-rest/src/app.module.ts (249 bytes)
CREATE /nest-rest/src/app.service.ts (142 bytes)
CREATE /nest-rest/src/main.ts (208 bytes)
CREATE /nest-rest/test/app.e2e-spec.ts (561 bytes)
CREATE /nest-rest/test/jest-e2e.json (183 bytes)

? Which package manager would you ️ to use? yarn
 Installation in progress... 

  Successfully created project nest-rest
  Get started with the following commands:

$ cd nest-rest
$ yarn run start

                          Thanks for installing Nest 
                 Please consider donating to our open collective
                        to help us maintain this package.

                 Donate: https://opencollective.com/nest

Odabrat ćemo yarn kao upravitelja paketa.
U ovom trenutku možete pokrenuti poslužitelj s naredbom npm start i odlazak na adresu http://localhost:3000 možete vidjeti glavnu stranicu. No, nismo se zato ovdje okupili i idemo dalje.

Postavljanje rada s bazom podataka

Izabrao sam PostrgreSQL kao DBMS za ovaj članak. O ukusima nema spora; po mom mišljenju, ovo je najzreliji DBMS, koji ima sve potrebne mogućnosti. Kao što je već spomenuto, Nest omogućuje integraciju s različitim paketima za rad s bazama podataka. Jer Kako je moj izbor pao na PostgreSQL, bilo bi logično odabrati TypeORM kao ORM. Instalirajmo potrebne pakete za integraciju s bazom podataka:

yarn add typeorm @nestjs/typeorm pg

Redom, za što je svaki paket potreban:

typeorm - paket izravno iz samog ORM-a;
@nestjs/typeorm - TypeORM paket za NestJS. Dodaje module za uvoz u module projekta, kao i skup pomoćnih dekoratora;
pg - upravljački program za rad s PostgreSQL.

U redu, paketi su instalirani, sada morate pokrenuti samu bazu podataka. Za implementaciju baze podataka, koristit ću docker-compose.yml sa sljedećim sadržajem:

doker-compose.yml

version: '3.1'

services:
  db:
    image: postgres:11.2
    restart: always
    environment:
      POSTGRES_PASSWORD: example
    volumes:
      - ../db:/var/lib/postgresql/data
      - ./postgresql.conf:/etc/postgresql/postgresql.conf
    ports:
      - 5432:5432
  adminer:
    image: adminer
    restart: always
    ports:
      - 8080:8080

Kao što vidite, ova datoteka konfigurira pokretanje 2 spremnika:

db je spremnik koji izravno sadrži bazu podataka. U našem slučaju koristi se postgresql verzija 11.2;
administrator—upravitelj baze podataka. Pruža web sučelje za pregled i upravljanje bazom podataka.

Za rad s tcp vezama, dodao sam sljedeću konfiguraciju.

postgresql.conf

# -----------------------------
# PostgreSQL configuration file
# -----------------------------
#
# This file consists of lines of the form:
#
#   name = value
#
# (The "=" is optional.)  Whitespace may be used.  Comments are introduced with
# "#" anywhere on a line.  The complete list of parameter names and allowed
# values can be found in the PostgreSQL documentation.
#
# The commented-out settings shown in this file represent the default values.
# Re-commenting a setting is NOT sufficient to revert it to the default value;
# you need to reload the server.
#
# This file is read on server startup and when the server receives a SIGHUP
# signal.  If you edit the file on a running system, you have to SIGHUP the
# server for the changes to take effect, run "pg_ctl reload", or execute
# "SELECT pg_reload_conf()".  Some parameters, which are marked below,
# require a server shutdown and restart to take effect.
#
# Any parameter can also be given as a command-line option to the server, e.g.,
# "postgres -c log_connections=on".  Some parameters can be changed at run time
# with the "SET" SQL command.
#
# Memory units:  kB = kilobytes        Time units:  ms  = milliseconds
#                MB = megabytes                     s   = seconds
#                GB = gigabytes                     min = minutes
#                TB = terabytes                     h   = hours
#                                                   d   = days
#------------------------------------------------------------------------------
# FILE LOCATIONS
#------------------------------------------------------------------------------
# The default values of these variables are driven from the -D command-line
# option or PGDATA environment variable, represented here as ConfigDir.
#data_directory = 'ConfigDir'       # use data in another directory
# (change requires restart)
#hba_file = 'ConfigDir/pg_hba.conf' # host-based authentication file
# (change requires restart)
#ident_file = 'ConfigDir/pg_ident.conf' # ident configuration file
# (change requires restart)
# If external_pid_file is not explicitly set, no extra PID file is written.
#external_pid_file = ''         # write an extra PID file
# (change requires restart)
#------------------------------------------------------------------------------
# CONNECTIONS AND AUTHENTICATION
#------------------------------------------------------------------------------
# - Connection Settings -
listen_addresses = '*'
#listen_addresses = 'localhost'     # what IP address(es) to listen on;
# comma-separated list of addresses;
# defaults to 'localhost'; use '*' for all
# (change requires restart)
#port = 5432                # (change requires restart)
#max_connections = 100          # (change requires restart)
#superuser_reserved_connections = 3 # (change requires restart)
#unix_socket_directories = '/tmp'   # comma-separated list of directories
# (change requires restart)
#unix_socket_group = ''         # (change requires restart)
#unix_socket_permissions = 0777     # begin with 0 to use octal notation
# (change requires restart)
#bonjour = off              # advertise server via Bonjour
# (change requires restart)
#bonjour_name = ''          # defaults to the computer name
# (change requires restart)
# - TCP Keepalives -
# see "man 7 tcp" for details
#tcp_keepalives_idle = 0        # TCP_KEEPIDLE, in seconds;
# 0 selects the system default
#tcp_keepalives_interval = 0        # TCP_KEEPINTVL, in seconds;
# 0 selects the system default
#tcp_keepalives_count = 0       # TCP_KEEPCNT;
# 0 selects the system default
# - Authentication -
#authentication_timeout = 1min      # 1s-600s
#password_encryption = md5      # md5 or scram-sha-256
#db_user_namespace = off
# GSSAPI using Kerberos
#krb_server_keyfile = ''
#krb_caseins_users = off
# - SSL -
#ssl = off
#ssl_ca_file = ''
#ssl_cert_file = 'server.crt'
#ssl_crl_file = ''
#ssl_key_file = 'server.key'
#ssl_ciphers = 'HIGH:MEDIUM:+3DES:!aNULL' # allowed SSL ciphers
#ssl_prefer_server_ciphers = on
#ssl_ecdh_curve = 'prime256v1'
#ssl_min_protocol_version = 'TLSv1'
#ssl_max_protocol_version = ''
#ssl_dh_params_file = ''
#ssl_passphrase_command = ''
#ssl_passphrase_command_supports_reload = off
#------------------------------------------------------------------------------
# RESOURCE USAGE (except WAL)
#------------------------------------------------------------------------------
# - Memory -
#shared_buffers = 32MB          # min 128kB
# (change requires restart)
#huge_pages = try           # on, off, or try
# (change requires restart)
#temp_buffers = 8MB         # min 800kB
#max_prepared_transactions = 0      # zero disables the feature
# (change requires restart)
# Caution: it is not advisable to set max_prepared_transactions nonzero unless
# you actively intend to use prepared transactions.
#work_mem = 4MB             # min 64kB
#maintenance_work_mem = 64MB        # min 1MB
#autovacuum_work_mem = -1       # min 1MB, or -1 to use maintenance_work_mem
#max_stack_depth = 2MB          # min 100kB
#shared_memory_type = mmap      # the default is the first option
# supported by the operating system:
#   mmap
#   sysv
#   windows
# (change requires restart)
#dynamic_shared_memory_type = posix # the default is the first option
# supported by the operating system:
#   posix
#   sysv
#   windows
#   mmap
# (change requires restart)
# - Disk -
#temp_file_limit = -1           # limits per-process temp file space
# in kB, or -1 for no limit
# - Kernel Resources -
#max_files_per_process = 1000       # min 25
# (change requires restart)
# - Cost-Based Vacuum Delay -
#vacuum_cost_delay = 0          # 0-100 milliseconds (0 disables)
#vacuum_cost_page_hit = 1       # 0-10000 credits
#vacuum_cost_page_miss = 10     # 0-10000 credits
#vacuum_cost_page_dirty = 20        # 0-10000 credits
#vacuum_cost_limit = 200        # 1-10000 credits
# - Background Writer -
#bgwriter_delay = 200ms         # 10-10000ms between rounds
#bgwriter_lru_maxpages = 100        # max buffers written/round, 0 disables
#bgwriter_lru_multiplier = 2.0      # 0-10.0 multiplier on buffers scanned/round
#bgwriter_flush_after = 0       # measured in pages, 0 disables
# - Asynchronous Behavior -
#effective_io_concurrency = 1       # 1-1000; 0 disables prefetching
#max_worker_processes = 8       # (change requires restart)
#max_parallel_maintenance_workers = 2   # taken from max_parallel_workers
#max_parallel_workers_per_gather = 2    # taken from max_parallel_workers
#parallel_leader_participation = on
#max_parallel_workers = 8       # maximum number of max_worker_processes that
# can be used in parallel operations
#old_snapshot_threshold = -1        # 1min-60d; -1 disables; 0 is immediate
# (change requires restart)
#backend_flush_after = 0        # measured in pages, 0 disables
#------------------------------------------------------------------------------
# WRITE-AHEAD LOG
#------------------------------------------------------------------------------
# - Settings -
#wal_level = replica            # minimal, replica, or logical
# (change requires restart)
#fsync = on             # flush data to disk for crash safety
# (turning this off can cause
# unrecoverable data corruption)
#synchronous_commit = on        # synchronization level;
# off, local, remote_write, remote_apply, or on
#wal_sync_method = fsync        # the default is the first option
# supported by the operating system:
#   open_datasync
#   fdatasync (default on Linux)
#   fsync
#   fsync_writethrough
#   open_sync
#full_page_writes = on          # recover from partial page writes
#wal_compression = off          # enable compression of full-page writes
#wal_log_hints = off            # also do full page writes of non-critical updates
# (change requires restart)
#wal_buffers = -1           # min 32kB, -1 sets based on shared_buffers
# (change requires restart)
#wal_writer_delay = 200ms       # 1-10000 milliseconds
#wal_writer_flush_after = 1MB       # measured in pages, 0 disables
#commit_delay = 0           # range 0-100000, in microseconds
#commit_siblings = 5            # range 1-1000
# - Checkpoints -
#checkpoint_timeout = 5min      # range 30s-1d
#max_wal_size = 1GB
#min_wal_size = 80MB
#checkpoint_completion_target = 0.5 # checkpoint target duration, 0.0 - 1.0
#checkpoint_flush_after = 0     # measured in pages, 0 disables
#checkpoint_warning = 30s       # 0 disables
# - Archiving -
#archive_mode = off     # enables archiving; off, on, or always
# (change requires restart)
#archive_command = ''       # command to use to archive a logfile segment
# placeholders: %p = path of file to archive
#               %f = file name only
# e.g. 'test ! -f /mnt/server/archivedir/%f && cp %p /mnt/server/archivedir/%f'
#archive_timeout = 0        # force a logfile segment switch after this
# number of seconds; 0 disables
# - Archive Recovery -
# These are only used in recovery mode.
#restore_command = ''       # command to use to restore an archived logfile segment
# placeholders: %p = path of file to restore
#               %f = file name only
# e.g. 'cp /mnt/server/archivedir/%f %p'
# (change requires restart)
#archive_cleanup_command = ''   # command to execute at every restartpoint
#recovery_end_command = ''  # command to execute at completion of recovery
# - Recovery Target -
# Set these only when performing a targeted recovery.
#recovery_target = ''       # 'immediate' to end recovery as soon as a
# consistent state is reached
# (change requires restart)
#recovery_target_name = ''  # the named restore point to which recovery will proceed
# (change requires restart)
#recovery_target_time = ''  # the time stamp up to which recovery will proceed
# (change requires restart)
#recovery_target_xid = ''   # the transaction ID up to which recovery will proceed
# (change requires restart)
#recovery_target_lsn = ''   # the WAL LSN up to which recovery will proceed
# (change requires restart)
#recovery_target_inclusive = on # Specifies whether to stop:
# just after the specified recovery target (on)
# just before the recovery target (off)
# (change requires restart)
#recovery_target_timeline = 'latest'    # 'current', 'latest', or timeline ID
# (change requires restart)
#recovery_target_action = 'pause'   # 'pause', 'promote', 'shutdown'
# (change requires restart)
#------------------------------------------------------------------------------
# REPLICATION
#------------------------------------------------------------------------------
# - Sending Servers -
# Set these on the master and on any standby that will send replication data.
#max_wal_senders = 10       # max number of walsender processes
# (change requires restart)
#wal_keep_segments = 0      # in logfile segments; 0 disables
#wal_sender_timeout = 60s   # in milliseconds; 0 disables
#max_replication_slots = 10 # max number of replication slots
# (change requires restart)
#track_commit_timestamp = off   # collect timestamp of transaction commit
# (change requires restart)
# - Master Server -
# These settings are ignored on a standby server.
#synchronous_standby_names = '' # standby servers that provide sync rep
# method to choose sync standbys, number of sync standbys,
# and comma-separated list of application_name
# from standby(s); '*' = all
#vacuum_defer_cleanup_age = 0   # number of xacts by which cleanup is delayed
# - Standby Servers -
# These settings are ignored on a master server.
#primary_conninfo = ''          # connection string to sending server
# (change requires restart)
#primary_slot_name = ''         # replication slot on sending server
# (change requires restart)
#promote_trigger_file = ''      # file name whose presence ends recovery
#hot_standby = on           # "off" disallows queries during recovery
# (change requires restart)
#max_standby_archive_delay = 30s    # max delay before canceling queries
# when reading WAL from archive;
# -1 allows indefinite delay
#max_standby_streaming_delay = 30s  # max delay before canceling queries
# when reading streaming WAL;
# -1 allows indefinite delay
#wal_receiver_status_interval = 10s # send replies at least this often
# 0 disables
#hot_standby_feedback = off     # send info from standby to prevent
# query conflicts
#wal_receiver_timeout = 60s     # time that receiver waits for
# communication from master
# in milliseconds; 0 disables
#wal_retrieve_retry_interval = 5s   # time to wait before retrying to
# retrieve WAL after a failed attempt
#recovery_min_apply_delay = 0       # minimum delay for applying changes during recovery
# - Subscribers -
# These settings are ignored on a publisher.
#max_logical_replication_workers = 4    # taken from max_worker_processes
# (change requires restart)
#max_sync_workers_per_subscription = 2  # taken from max_logical_replication_workers
#------------------------------------------------------------------------------
# QUERY TUNING
#------------------------------------------------------------------------------
# - Planner Method Configuration -
#enable_bitmapscan = on
#enable_hashagg = on
#enable_hashjoin = on
#enable_indexscan = on
#enable_indexonlyscan = on
#enable_material = on
#enable_mergejoin = on
#enable_nestloop = on
#enable_parallel_append = on
#enable_seqscan = on
#enable_sort = on
#enable_tidscan = on
#enable_partitionwise_join = off
#enable_partitionwise_aggregate = off
#enable_parallel_hash = on
#enable_partition_pruning = on
# - Planner Cost Constants -
#seq_page_cost = 1.0            # measured on an arbitrary scale
#random_page_cost = 4.0         # same scale as above
#cpu_tuple_cost = 0.01          # same scale as above
#cpu_index_tuple_cost = 0.005       # same scale as above
#cpu_operator_cost = 0.0025     # same scale as above
#parallel_tuple_cost = 0.1      # same scale as above
#parallel_setup_cost = 1000.0   # same scale as above
#jit_above_cost = 100000        # perform JIT compilation if available
# and query more expensive than this;
# -1 disables
#jit_inline_above_cost = 500000     # inline small functions if query is
# more expensive than this; -1 disables
#jit_optimize_above_cost = 500000   # use expensive JIT optimizations if
# query is more expensive than this;
# -1 disables
#min_parallel_table_scan_size = 8MB
#min_parallel_index_scan_size = 512kB
#effective_cache_size = 4GB
# - Genetic Query Optimizer -
#geqo = on
#geqo_threshold = 12
#geqo_effort = 5            # range 1-10
#geqo_pool_size = 0         # selects default based on effort
#geqo_generations = 0           # selects default based on effort
#geqo_selection_bias = 2.0      # range 1.5-2.0
#geqo_seed = 0.0            # range 0.0-1.0
# - Other Planner Options -
#default_statistics_target = 100    # range 1-10000
#constraint_exclusion = partition   # on, off, or partition
#cursor_tuple_fraction = 0.1        # range 0.0-1.0
#from_collapse_limit = 8
#join_collapse_limit = 8        # 1 disables collapsing of explicit
# JOIN clauses
#force_parallel_mode = off
#jit = on               # allow JIT compilation
#plan_cache_mode = auto         # auto, force_generic_plan or
# force_custom_plan
#------------------------------------------------------------------------------
# REPORTING AND LOGGING
#------------------------------------------------------------------------------
# - Where to Log -
#log_destination = 'stderr'     # Valid values are combinations of
# stderr, csvlog, syslog, and eventlog,
# depending on platform.  csvlog
# requires logging_collector to be on.
# This is used when logging to stderr:
#logging_collector = off        # Enable capturing of stderr and csvlog
# into log files. Required to be on for
# csvlogs.
# (change requires restart)
# These are only used if logging_collector is on:
#log_directory = 'log'          # directory where log files are written,
# can be absolute or relative to PGDATA
#log_filename = 'postgresql-%Y-%m-%d_%H%M%S.log'    # log file name pattern,
# can include strftime() escapes
#log_file_mode = 0600           # creation mode for log files,
# begin with 0 to use octal notation
#log_truncate_on_rotation = off     # If on, an existing log file with the
# same name as the new log file will be
# truncated rather than appended to.
# But such truncation only occurs on
# time-driven rotation, not on restarts
# or size-driven rotation.  Default is
# off, meaning append to existing files
# in all cases.
#log_rotation_age = 1d          # Automatic rotation of logfiles will
# happen after that time.  0 disables.
#log_rotation_size = 10MB       # Automatic rotation of logfiles will
# happen after that much log output.
# 0 disables.
# These are relevant when logging to syslog:
#syslog_facility = 'LOCAL0'
#syslog_ident = 'postgres'
#syslog_sequence_numbers = on
#syslog_split_messages = on
# This is only relevant when logging to eventlog (win32):
# (change requires restart)
#event_source = 'PostgreSQL'
# - When to Log -
#log_min_messages = warning     # values in order of decreasing detail:
#   debug5
#   debug4
#   debug3
#   debug2
#   debug1
#   info
#   notice
#   warning
#   error
#   log
#   fatal
#   panic
#log_min_error_statement = error    # values in order of decreasing detail:
#   debug5
#   debug4
#   debug3
#   debug2
#   debug1
#   info
#   notice
#   warning
#   error
#   log
#   fatal
#   panic (effectively off)
#log_min_duration_statement = -1    # logs statements and their durations
# according to log_statement_sample_rate. -1 is disabled,
# 0 logs all statement, > 0 logs only statements running at
# least this number of milliseconds.
#log_statement_sample_rate = 1  # Fraction of logged statements over
# log_min_duration_statement. 1.0 logs all statements,
# 0 never logs.
# - What to Log -
#debug_print_parse = off
#debug_print_rewritten = off
#debug_print_plan = off
#debug_pretty_print = on
#log_checkpoints = off
#log_connections = off
#log_disconnections = off
#log_duration = off
#log_error_verbosity = default      # terse, default, or verbose messages
#log_hostname = off
#log_line_prefix = '%m [%p] '       # special values:
#   %a = application name
#   %u = user name
#   %d = database name
#   %r = remote host and port
#   %h = remote host
#   %p = process ID
#   %t = timestamp without milliseconds
#   %m = timestamp with milliseconds
#   %n = timestamp with milliseconds (as a Unix epoch)
#   %i = command tag
#   %e = SQL state
#   %c = session ID
#   %l = session line number
#   %s = session start timestamp
#   %v = virtual transaction ID
#   %x = transaction ID (0 if none)
#   %q = stop here in non-session
#        processes
#   %% = '%'
# e.g. '<%u%%%d> '
#log_lock_waits = off           # log lock waits >= deadlock_timeout
#log_statement = 'none'         # none, ddl, mod, all
#log_replication_commands = off
#log_temp_files = -1            # log temporary files equal or larger
# than the specified size in kilobytes;
# -1 disables, 0 logs all temp files
#log_timezone = 'GMT'
#------------------------------------------------------------------------------
# PROCESS TITLE
#------------------------------------------------------------------------------
#cluster_name = ''          # added to process titles if nonempty
# (change requires restart)
#update_process_title = on
#------------------------------------------------------------------------------
# STATISTICS
#------------------------------------------------------------------------------
# - Query and Index Statistics Collector -
#track_activities = on
#track_counts = on
#track_io_timing = off
#track_functions = none         # none, pl, all
#track_activity_query_size = 1024   # (change requires restart)
#stats_temp_directory = 'pg_stat_tmp'
# - Monitoring -
#log_parser_stats = off
#log_planner_stats = off
#log_executor_stats = off
#log_statement_stats = off
#------------------------------------------------------------------------------
# AUTOVACUUM
#------------------------------------------------------------------------------
#autovacuum = on            # Enable autovacuum subprocess?  'on'
# requires track_counts to also be on.
#log_autovacuum_min_duration = -1   # -1 disables, 0 logs all actions and
# their durations, > 0 logs only
# actions running at least this number
# of milliseconds.
#autovacuum_max_workers = 3     # max number of autovacuum subprocesses
# (change requires restart)
#autovacuum_naptime = 1min      # time between autovacuum runs
#autovacuum_vacuum_threshold = 50   # min number of row updates before
# vacuum
#autovacuum_analyze_threshold = 50  # min number of row updates before
# analyze
#autovacuum_vacuum_scale_factor = 0.2   # fraction of table size before vacuum
#autovacuum_analyze_scale_factor = 0.1  # fraction of table size before analyze
#autovacuum_freeze_max_age = 200000000  # maximum XID age before forced vacuum
# (change requires restart)
#autovacuum_multixact_freeze_max_age = 400000000    # maximum multixact age
# before forced vacuum
# (change requires restart)
#autovacuum_vacuum_cost_delay = 2ms # default vacuum cost delay for
# autovacuum, in milliseconds;
# -1 means use vacuum_cost_delay
#autovacuum_vacuum_cost_limit = -1  # default vacuum cost limit for
# autovacuum, -1 means use
# vacuum_cost_limit
#------------------------------------------------------------------------------
# CLIENT CONNECTION DEFAULTS
#------------------------------------------------------------------------------
# - Statement Behavior -
#client_min_messages = notice       # values in order of decreasing detail:
#   debug5
#   debug4
#   debug3
#   debug2
#   debug1
#   log
#   notice
#   warning
#   error
#search_path = '"$user", public'    # schema names
#row_security = on
#default_tablespace = ''        # a tablespace name, '' uses the default
#temp_tablespaces = ''          # a list of tablespace names, '' uses
# only default tablespace
#check_function_bodies = on
#default_transaction_isolation = 'read committed'
#default_transaction_read_only = off
#default_transaction_deferrable = off
#session_replication_role = 'origin'
#statement_timeout = 0          # in milliseconds, 0 is disabled
#lock_timeout = 0           # in milliseconds, 0 is disabled
#idle_in_transaction_session_timeout = 0    # in milliseconds, 0 is disabled
#vacuum_freeze_min_age = 50000000
#vacuum_freeze_table_age = 150000000
#vacuum_multixact_freeze_min_age = 5000000
#vacuum_multixact_freeze_table_age = 150000000
#vacuum_cleanup_index_scale_factor = 0.1    # fraction of total number of tuples
# before index cleanup, 0 always performs
# index cleanup
#bytea_output = 'hex'           # hex, escape
#xmlbinary = 'base64'
#xmloption = 'content'
#gin_fuzzy_search_limit = 0
#gin_pending_list_limit = 4MB
# - Locale and Formatting -
#datestyle = 'iso, mdy'
#intervalstyle = 'postgres'
#timezone = 'GMT'
#timezone_abbreviations = 'Default'     # Select the set of available time zone
# abbreviations.  Currently, there are
#   Default
#   Australia (historical usage)
#   India
# You can create your own file in
# share/timezonesets/.
#extra_float_digits = 1         # min -15, max 3; any value >0 actually
# selects precise output mode
#client_encoding = sql_ascii        # actually, defaults to database
# encoding
# These settings are initialized by initdb, but they can be changed.
#lc_messages = 'C'          # locale for system error message
# strings
#lc_monetary = 'C'          # locale for monetary formatting
#lc_numeric = 'C'           # locale for number formatting
#lc_time = 'C'              # locale for time formatting
# default configuration for text search
#default_text_search_config = 'pg_catalog.simple'
# - Shared Library Preloading -
#shared_preload_libraries = ''  # (change requires restart)
#local_preload_libraries = ''
#session_preload_libraries = ''
#jit_provider = 'llvmjit'       # JIT library to use
# - Other Defaults -
#dynamic_library_path = '$libdir'
#------------------------------------------------------------------------------
# LOCK MANAGEMENT
#------------------------------------------------------------------------------
#deadlock_timeout = 1s
#max_locks_per_transaction = 64     # min 10
# (change requires restart)
#max_pred_locks_per_transaction = 64    # min 10
# (change requires restart)
#max_pred_locks_per_relation = -2   # negative values mean
# (max_pred_locks_per_transaction
#  / -max_pred_locks_per_relation) - 1
#max_pred_locks_per_page = 2            # min 0
#------------------------------------------------------------------------------
# VERSION AND PLATFORM COMPATIBILITY
#------------------------------------------------------------------------------
# - Previous PostgreSQL Versions -
#array_nulls = on
#backslash_quote = safe_encoding    # on, off, or safe_encoding
#escape_string_warning = on
#lo_compat_privileges = off
#operator_precedence_warning = off
#quote_all_identifiers = off
#standard_conforming_strings = on
#synchronize_seqscans = on
# - Other Platforms and Clients -
#transform_null_equals = off
#------------------------------------------------------------------------------
# ERROR HANDLING
#------------------------------------------------------------------------------
#exit_on_error = off            # terminate session on any error?
#restart_after_crash = on       # reinitialize after backend crash?
#data_sync_retry = off          # retry or panic on failure to fsync
# data?
# (change requires restart)
#------------------------------------------------------------------------------
# CONFIG FILE INCLUDES
#------------------------------------------------------------------------------
# These options allow settings to be loaded from files other than the
# default postgresql.conf.
#include_dir = 'conf.d'         # include files ending in '.conf' from
# directory 'conf.d'
#include_if_exists = 'exists.conf'  # include file only if it exists
#include = 'special.conf'       # include file
#------------------------------------------------------------------------------
# CUSTOMIZED OPTIONS
#------------------------------------------------------------------------------
# Add settings for extensions here

To je sve, možete pokrenuti spremnike s naredbom docker-compose up -d. Ili u zasebnoj konzoli s naredbom docker-compose up.

Dakle, paketi su instalirani, baza je pokrenuta, preostaje samo da ih međusobno sprijateljimo. Da biste to učinili, trebate dodati sljedeću datoteku u korijen projekta: ormconfig.js:

ormconfig.js

const process = require('process');
const username = process.env.POSTGRES_USER || "postgres";
const password = process.env.POSTGRES_PASSWORD || "example";
module.exports = {
"type": "postgres",
"host": "localhost",
"port": 5432,
username,
password,
"database": "postgres",
"synchronize": true,
"dropSchema": false,
"logging": true,
"entities": [__dirname + "/src/**/*.entity.ts", __dirname + "/dist/**/*.entity.js"],
"migrations": ["migrations/**/*.ts"],
"subscribers": ["subscriber/**/*.ts", "dist/subscriber/**/.js"],
"cli": {
"entitiesDir": "src",
"migrationsDir": "migrations",
"subscribersDir": "subscriber"
}
}

Ova konfiguracija će se koristiti za cli typeorm.

Pogledajmo detaljnije ovu konfiguraciju. U redovima 3 i 4 dobivamo korisničko ime i lozinku iz varijabli okoline. Ovo je zgodno kada imate nekoliko okruženja (dev, stage, prod itd.). Prema zadanim postavkama, korisničko ime je postgres, a lozinka je primjer. Ostatak konfiguracije je trivijalan, pa ćemo se usredotočiti samo na najzanimljivije parametre:

sinkroniziraj - Označava treba li se shema baze podataka automatski izraditi kada se aplikacija pokrene. Budite oprezni s ovom opcijom i nemojte je koristiti u proizvodnji, inače ćete izgubiti podatke. Ova je opcija praktična pri razvoju i uklanjanju pogrešaka u aplikaciji. Kao alternativu ovoj opciji, možete koristiti naredbu schema:sync iz CLI TypeORM.
dropSchema - resetirajte shemu svaki put kada se uspostavi veza. Kao i prethodnu, ovu opciju treba koristiti samo tijekom razvoja i otklanjanja pogrešaka aplikacije.
entiteta - kojim putovima tražiti opise modela. Imajte na umu da je podržano pretraživanje po maski.
cli.entitiesDir je direktorij u koji bi prema zadanim postavkama trebali biti pohranjeni modeli kreirani iz TypeORM CLI.

Kako bismo mogli koristiti sve značajke TypeORM-a u našoj Nest aplikaciji, moramo uvesti modul TypeOrmModule в AppModule. Oni. tvoje AppModule izgledat će ovako:

app.module.ts

import { Module } from '@nestjs/common';
import { AppController } from './app.controller';
import { AppService } from './app.service';
import { TypeOrmModule } from '@nestjs/typeorm';
import * as process from "process";
const username = process.env.POSTGRES_USER || 'postgres';
const password = process.env.POSTGRES_PASSWORD || 'example';
@Module({
imports: [
TypeOrmModule.forRoot({
type: 'postgres',
host: 'localhost',
port: 5432,
username,
password,
database: 'postgres',
entities: [__dirname + '/**/*.entity{.ts,.js}'],
synchronize: true,
}),
],
controllers: [AppController],
providers: [AppService],
})
export class AppModule {}

Kao što ste mogli primijetiti, metoda forRoot prenosi se ista konfiguracija za rad s bazom podataka kao u datoteci ormconfig.ts

Ostaje posljednji detalj - dodajte nekoliko zadataka za rad s TypeORM-om u package.json. Činjenica je da je CLI napisan u javascriptu i radi u nodejs okruženju. Međutim, svi naši modeli i migracije bit će napisani strojno. Stoga je potrebno transpilirati naše migracije i modele prije korištenja CLI-ja. Za ovo nam je potreban ts-node paket:

yarn add -D ts-node

Nakon toga dodajte potrebne naredbe u package.json:

"typeorm": "ts-node -r tsconfig-paths/register ./node_modules/typeorm/cli.js",
"migration:generate": "yarn run typeorm migration:generate -n",
"migration:create": "yarn run typeorm migration:create -n",
"migration:run": "yarn run typeorm migration:run"

Prva naredba, typeorm, dodaje omotač ts-node za pokretanje TypeORM cli. Preostale naredbe su zgodni prečaci koje ćete vi, kao programer, koristiti gotovo svaki dan:
migration:generate — stvaranje migracija na temelju promjena u vašim modelima.
migration:create — stvaranje prazne seobe.
migration:run — pokretanje migracija.
E, to je to sada, dodali smo potrebne pakete, konfigurirali aplikaciju da radi s bazom podataka i iz cli-a i iz same aplikacije, a također smo pokrenuli DBMS. Vrijeme je da dodamo logiku našoj aplikaciji.

Instalacija paketa za kreiranje CRUD-a

Koristeći samo Nest, možete stvoriti API koji vam omogućuje stvaranje, čitanje, ažuriranje i brisanje entiteta. Ovo će rješenje biti što je moguće fleksibilnije, ali u nekim slučajevima bit će suvišno. Na primjer, ako trebate brzo izraditi prototip, često možete žrtvovati fleksibilnost radi brzine razvoja. Mnogi okviri pružaju funkcionalnost za generiranje CRUD-a opisivanjem podatkovnog modela određenog entiteta. I Nest nije iznimka! Ovu funkcionalnost osigurava paket @nestjsx/crud. Njegove mogućnosti su vrlo zanimljive:

jednostavna instalacija i konfiguracija;
DBMS neovisnost;
snažan upitni jezik s mogućnošću filtriranja, paginiranja, sortiranja, učitavanja odnosa i ugniježđenih entiteta, predmemoriranja itd.;
paket za generiranje zahtjeva na front-endu;
jednostavno nadjačavanje metoda kontrolera;
mala konfiguracija;
swagger podrška dokumentaciji.

Funkcionalnost je podijeljena u nekoliko paketa:

@nestjsx/crud - osnovni paket koji dekorater daje Crud() za generiranje rute, konfiguraciju i provjeru valjanosti;
@nestjsx/crud-request — paket koji pruža alat za sastavljanje/parser upita za korištenje na strani sučelja;
@nestjsx/crud-typeorm — paket za integraciju s TypeORM-om koji pruža osnovnu uslugu TypeOrmCrudService s CRUD metodama za rad s entitetima u bazi podataka.

U ovom vodiču trebat će nam paketi gnijezdojsx/crud i gnijezdojsx/crud-typeorm. Prvo, stavimo ih

yarn add @nestjsx/crud class-transformer class-validator

Paketi klasa-transformator и klasa-validator u ovoj aplikaciji potrebni su za deklarativni opis pravila za transformaciju instanci modela i provjeru valjanosti dolaznih zahtjeva. Ovi paketi su od istog autora, tako da su sučelja slična.

Izravna implementacija CRUD-a

Kao primjer modela uzet ćemo popis korisnika. Korisnici će imati sljedeća polja: id, username, displayName, email. id - autoinkrementirajuće polje, email и username - jedinstvena polja. Jednostavno je! Ostalo je samo implementirati našu ideju u obliku Nest aplikacije.
Prvo morate izraditi modul users, koji će biti zadužen za rad s korisnicima. Upotrijebimo cli iz NestJS-a i izvršimo naredbu u korijenskom direktoriju našeg projekta nest g module users.

korisnici nest g modula

dmitrii@dmitrii-HP-ZBook-17-G3:~/projects/nest-rest git:(master*)$ nest g module users
CREATE /src/users/users.module.ts (82 bytes)
UPDATE /src/app.module.ts (312 bytes)

U ovom modulu ćemo dodati mapu entiteta, gdje ćemo imati modele ovog modula. Konkretno, dodajmo ovdje datoteku user.entity.ts s opisom korisničkog modela:

korisnik.entitet.ts

import { Column, Entity, PrimaryGeneratedColumn } from 'typeorm';
@Entity()
export class User {
@PrimaryGeneratedColumn()
id: string;
@Column({unique: true})
email: string;
@Column({unique: true})
username: string;
@Column({nullable: true})
displayName: string;
}

Da bi ovaj model “vidjela” naša aplikacija potrebno je u modulu UsersModule uvoz TypeOrmModule sljedeći sadržaj:

korisnici.modul.ts

import { Module } from '@nestjs/common';
import { UsersController } from './controllers/users/users.controller';
import { UsersService } from './services/users/users.service';
import { TypeOrmModule } from '@nestjs/typeorm';
import { User } from './entities/user.entity';
@Module({
controllers: [UsersController],
providers: [UsersService],
imports: [
TypeOrmModule.forFeature([User])
]
})
export class UsersModule {}

Odnosno, ovdje uvozimo TypeOrmModule, gdje kao parametar metode forFeature Navodimo popis modela koji se odnose na ovaj modul.

Sve što preostaje je kreirati odgovarajući entitet u bazi podataka. U te svrhe služi mehanizam migracije. Da biste kreirali migraciju na temelju promjena u modelima, morate pokrenuti naredbu npm run migration:generate -- CreateUserTable:

Naslov spojlera

$ npm run migration:generate -- CreateUserTable
Migration /home/dmitrii/projects/nest-rest/migrations/1563346135367-CreateUserTable.ts has been generated successfully.
Done in 1.96s.

Nismo morali ručno pisati migraciju, sve se dogodilo magično. Nije li ovo čudo! Međutim, to nije sve. Pogledajmo stvorenu datoteku za migraciju:

1563346135367-CreateUserTable.ts

import {MigrationInterface, QueryRunner} from "typeorm";
export class CreateUserTable1563346816726 implements MigrationInterface {
public async up(queryRunner: QueryRunner): Promise<any> {
await queryRunner.query(`CREATE TABLE "user" ("id" SERIAL NOT NULL, "email" character varying NOT NULL, "username" character varying NOT NULL, "displayName" character varying, CONSTRAINT "UQ_e12875dfb3b1d92d7d7c5377e22" UNIQUE ("email"), CONSTRAINT "UQ_78a916df40e02a9deb1c4b75edb" UNIQUE ("username"), CONSTRAINT "PK_cace4a159ff9f2512dd42373760" PRIMARY KEY ("id"))`);
}
public async down(queryRunner: QueryRunner): Promise<any> {
await queryRunner.query(`DROP TABLE "user"`);
}
}

Kao što vidite, nije automatski generirana samo metoda za pokretanje migracije, već i metoda za njezino vraćanje. Fantastičan!
Sve što preostaje je pokrenuti ovu migraciju. To se radi sljedećom naredbom:

npm run migration:run.

To je to, sada su promjene sheme migrirale u bazu podataka.
Zatim ćemo napraviti servis koji će biti odgovoran za rad s korisnicima i naslijediti ga TypeOrmCrudService. Repozitorij entiteta od interesa mora se proslijediti parametru nadređenog konstruktora, u našem slučaju User spremište.

korisnici.usluga.ts

import { Injectable } from '@nestjs/common';
import { TypeOrmCrudService } from '@nestjsx/crud-typeorm';
import { User } from '../../entities/user.entity';
import { InjectRepository } from '@nestjs/typeorm';
import { Repository } from 'typeorm';
@Injectable()
export class UsersService extends TypeOrmCrudService<User>{
constructor(@InjectRepository(User) usersRepository: Repository<User>){
super(usersRepository);
}
}

Trebat ćemo ovu uslugu u kontroleru users. Za izradu kontrolera upišite u konzolu nest g controller users/controllers/users

gnijezdo g kontroler korisnici/kontroleri/korisnici

dmitrii@dmitrii-HP-ZBook-17-G3:~/projects/nest-rest git:(master*)$ nest g controller users/controllers/users
CREATE /src/users/controllers/users/users.controller.spec.ts (486 bytes)
CREATE /src/users/controllers/users/users.controller.ts (99 bytes)
UPDATE /src/users/users.module.ts (188 bytes)

Otvorimo ovaj kontroler i uredimo ga da dodamo malo magije gnijezdojsx/crud. Po klasi UsersController Dodajmo dekorater poput ovog:

@Crud({
model: {
type: User
}
})

Crud je dekorater koji kontroleru dodaje potrebne metode za rad s modelom. Tip modela je naznačen u polju model.type konfiguracije dekoratera.
Drugi korak je implementacija sučelja CrudController<User>. "Sastavljeni" kod kontrolera izgleda ovako:

import { Controller } from '@nestjs/common';
import { Crud, CrudController } from '@nestjsx/crud';
import { User } from '../../entities/user.entity';
import { UsersService } from '../../services/users/users.service';
@Crud({
model: {
type: User
}
})
@Controller('users')
export class UsersController implements CrudController<User>{
constructor(public service: UsersService){}
}

I to je sve! Sada kontroler podržava cijeli niz operacija s modelom! Ne vjeruješ mi? Isprobajmo našu aplikaciju na djelu!

Stvaranje skripte upita u TestMaceu

Za testiranje naše usluge koristit ćemo IDE za rad s API-jem TestMace. Zašto TestMace? U usporedbi sa sličnim proizvodima, ima sljedeće prednosti:

snažan rad s varijablama. U ovom trenutku postoji nekoliko vrsta varijabli, od kojih svaka ima određenu ulogu: ugrađene varijable, dinamičke varijable, varijable okruženja. Svaka varijabla pripada čvoru s podrškom za mehanizam nasljeđivanja;
Jednostavno izradite skripte bez programiranja. O tome će biti riječi u nastavku;
čovjeku čitljiv format koji vam omogućuje spremanje projekta u sustavima za kontrolu verzija;
automatsko dovršavanje, označavanje sintakse, označavanje vrijednosti varijable;
Podrška za opis API-ja s mogućnošću uvoza iz Swaggera.

Pokrenimo naš poslužitelj naredbom npm start i pokušajte pristupiti popisu korisnika. Popis korisnika, sudeći prema konfiguraciji našeg kontrolera, možete dobiti na url localhost:3000/users. Pošaljimo zahtjev na ovaj url.
Nakon pokretanja TestMacea možete vidjeti ovakvo sučelje:

Gore lijevo nalazi se stablo projekta s korijenskim čvorom Projekt. Pokušajmo kreirati prvi zahtjev za dobivanje popisa korisnika. Za ovo ćemo stvoriti RequestStep čvor To se radi u kontekstnom izborniku čvora Projekt Dodaj čvor -> RequestStep.

U polje URL zalijepite localhost:3000/users i pokrenite zahtjev. Primit ćemo kod 200 s praznim nizom u tijelu odgovora. Razumljivo je, još nikoga nismo dodali.
Kreirajmo skriptu koja će sadržavati sljedeće korake:

stvaranje korisnika;
zahtjev za ID-om novokreiranog korisnika;
brisanje korisničkim ID-om stvorenim u 1. koraku.

Pa, idemo. Radi praktičnosti, stvorimo čvor poput Mapa. U biti, ovo je samo mapa u koju ćemo spremiti cijelu skriptu. Da biste stvorili čvor mape, odaberite Projekt iz kontekstnog izbornika čvora Dodaj čvor -> Mapa. Nazovimo čvor provjeri-kreiraj. Unutar čvora provjeri-kreiraj Kreirajmo naš prvi zahtjev za stvaranje korisnika. Nazovimo novostvoreni čvor stvoriti-korisnik. To jest, u ovom trenutku će hijerarhija čvorova izgledati ovako:

Idemo na otvorenu karticu stvoriti-korisnik čvor. Unesite sljedeće parametre za zahtjev:

Vrsta zahtjeva - POST
URL - localhost:3000/users
Tijelo - JSON s vrijednošću {"email": "[email protected]", "displayName": "New user", "username": "user"}

Ispunimo ovaj zahtjev. Naša aplikacija kaže da je zapis kreiran.

Pa, provjerimo ovu činjenicu. Kako biste radili s ID-om kreiranog korisnika u sljedećim koracima, ovaj parametar mora biti spremljen. Mehanizam je savršen za to. dinamičke varijable. Iskoristimo naš primjer da pogledamo kako raditi s njima. U raščlanjenoj kartici odgovora, pored id čvora u kontekstnom izborniku odaberite stavku Dodijeli varijabli. U dijaloškom okviru morate postaviti sljedeće parametre:

Čvor — u kojem od predaka stvoriti dinamičku varijablu. Izaberimo provjeri-kreiraj
Naziv varijable — naziv ove varijable. Nazovimo userId.

Evo kako izgleda proces stvaranja dinamičke varijable:

Sada, svaki put kada se ovaj upit izvrši, vrijednost dinamičke varijable će se ažurirati. I zato što dinamičke varijable podržavaju mehanizam hijerarhijskog nasljeđivanja, varijabla userId bit će dostupni u potomcima provjeri-kreiraj čvor bilo koje razine ugniježđenja.
Ova varijabla će nam biti korisna u sljedećem zahtjevu. Naime, zatražit ćemo novokreiranog korisnika. Kao dijete čvora provjeri-kreiraj kreirat ćemo zahtjev provjerite postoji li s parametrom url jednak localhost:3000/users/${$dynamicVar.userId}. Pogledaj dizajn ${variable_name} ovo je dobivanje vrijednosti varijable. Jer Imamo dinamičku varijablu, pa da biste je dobili morate pristupiti objektu $dynamicVar, tj. potpuni pristup dinamičkoj varijabli userId izgledat će ovako ${$dynamicVar.userId}. Izvršimo zahtjev i uvjerimo se da su traženi podaci točni.
Zadnji preostali korak je zatražiti brisanje. Treba nam ne samo da provjerimo rad brisanja, nego i da takoreći počistimo za sobom u bazi podataka, jer Polja za e-poštu i korisničko ime su jedinstvena. Dakle, u čvoru provjere i stvaranja kreirat ćemo zahtjev za brisanje korisnika sa sljedećim parametrima

Vrsta zahtjeva - IZBRIŠI
URL - localhost:3000/users/${$dynamicVar.userId}

Idemo lansirati. Čekamo. Uživamo u rezultatu)

Pa, sada možemo pokrenuti cijelu skriptu bilo kada. Za pokretanje skripte morate odabrati iz kontekstnog izbornika provjeri-kreiraj čvorna stavka trčanje.

Čvorovi u skripti će se izvršavati jedan za drugim
Ovu skriptu možete spremiti u svoj projekt pokretanjem Datoteka -> Spremi projekt.

Zaključak

Sve značajke korištenih alata jednostavno nisu mogle stati u format ovog članka. Što se tiče glavnog krivca – paketa gnijezdojsx/crud - sljedeće teme ostaju nepokrivene:

prilagođena provjera valjanosti i transformacija modela;
moćan upitni jezik i njegova praktična upotreba na prednjoj strani;
redefiniranje i dodavanje novih metoda crud kontrolerima;
podrška razmetanja;
upravljanje predmemoriranjem.

Međutim, čak i ono što je opisano u članku dovoljno je da shvatimo da čak i takav enterprise framework kao što je NestJS ima alate za brzu izradu prototipova aplikacija. I tako cool IDE poput TestMace omogućuje vam održavanje zadanog tempa.

Izvorni kod za ovaj članak, zajedno s projektom TestMace, dostupan u repozitoriju https://github.com/TestMace/nest-rest. Za otvaranje projekta TestMace samo to učinite u aplikaciji Datoteka -> Otvori projekt.

Izvor: www.habr.com

Brzo stvaranje CRUD-a s gnijezdom, @nestjsx/crud i TestMace