目前，REST API 已成為 Web 應用程序開發的標準，允許您將開發分解為獨立的部分。 對於 UI，目前使用各種流行的框架，例如 Angular、React、Vue 等。 後端開發人員可以從種類繁多的語言和框架中進行選擇。 今天我想談談這樣一個框架 . 我們在 我們積極將其用於內部項目。 使用嵌套和包 ，我們將創建一個簡單的 CRUD 應用程序。
為什麼選擇 NestJS
最近，JavaScript 社區出現了相當多的後端框架。 如果在功能方面它們提供了類似於 Nest 的機會，那麼它肯定會在一件事上獲勝——這就是架構。 以下 NestJS 功能允許您創建工業應用程序並將開發擴展到大型團隊：
- 使用 TypeScript 作為主要開發語言。 儘管 NestJS 支持 JavaScript，但某些功能可能無法使用，尤其是涉及到第三方包時；
- 存在 DI 容器，它允許您創建鬆散耦合的組件；
- 框架本身的功能分為獨立的可互換組件。 例如，在引擎蓋下作為一個框架可以用作 和 , 開箱即用的嵌套數據庫提供了綁定 , , ;
- NestJS 是平台獨立的，支持 REST、GraphQL、Websockets、gRPC 等。
該框架本身受到 Angular 前端框架的啟發，並且在概念上與它有很多共同之處。
安裝 NestJS 並部署項目
Nest 包含一個包 /cli，可以讓你快速部署一個基本的應用框架。 全局安裝這個包：
npm install --global @nest/cli安裝後，我們將生成我們應用程序的基本框架，名稱為 嵌套資源噸。 這是使用命令完成的 nest new nest-rest.
巢新巢休息
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我們將選擇 yarn 作為我們的包管理器。
現在，您可以使用以下命令啟動服務器 npm start 去地址 你可以看到主頁。 然而，這不是我們來這裡的目的，我們正在繼續前進。
設置數據庫工作
我選擇 PostrgreSQL 作為本文的 DBMS。 沒有任何關於口味的爭議，在我看來，這是具有所有必要功能的最成熟的 DBMS。 如前所述，Nest 提供了與各種用於處理數據庫的包的集成。 因為由於我的選擇落在了 PostgreSQL 上，因此選擇 TypeORM 作為 ORM 是合乎邏輯的。 安裝與數據庫集成所需的包：
yarn add typeorm @nestjs/typeorm pg
按順序，每個包的用途：
- typeorm - 直接來自 ORM 本身的包；
- @nestjs/typeorm - NestJS 的 TypeORM 包。 添加用於導入項目模塊的模塊，以及一組輔助裝飾器；
- pg 是與 PostgreSQL 一起工作的驅動程序。
好的，包已經安裝好了，現在你需要啟動數據庫本身。 為了部署基礎，我將使用包含以下內容的 docker-compose.yml：
泊塢窗，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如您所見，此文件配置了 2 個容器的啟動：
- db 是直接帶有數據庫的容器。 在我們的例子中，使用 postgresql 版本 11.2；
- 管理員 - 數據庫管理員。 提供用於查看和管理數據庫的 Web 界面。
為了使用 tcp 連接，我添加了以下配置。
配置文件
# -----------------------------
# 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就是這樣，您可以使用命令運行容器 docker-compose up -d. 或者在單獨的控制台中使用命令 docker-compose up.
因此，安裝了軟件包，啟動了基礎，剩下的就是讓他們彼此成為朋友。 為此，將 ormconfig.js 文件添加到項目的根目錄中，內容如下：
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"
}
}
此配置將用於 cli typeorm。
讓我們仔細看看這個配置。 在第 3 行和第 4 行中，我們從環境變量中獲取用戶名和密碼。 當您有多個環境（開發、階段、生產等）時，這很方便。 默認用戶名是 postgres，密碼是 example。 否則，配置是微不足道的，所以我們將只關注最有趣的參數：
- synchronize 指定數據庫模式是否應在應用程序啟動時自動創建。 請小心使用此選項，不要在生產中使用它，否則您將丟失數據。 此選項在開發和調試應用程序時很有用。 作為此選項的替代方法，您可以使用以下命令
schema:sync來自 CLI TypeORM。 - dropSchema - 每次建立連接時刪除架構。 此外，與前一個選項一樣，此選項應僅在應用程序的開發和調試期間使用。
- entities - 查找模型描述的路徑。 請注意，支持掩碼搜索。
- cli.entitiesDir 是默認情況下應添加從 CLI TypeORM 創建的模型的目錄。
為了讓我們在 Nest 應用程序中使用 TypeORM 的所有功能，我們需要導入模塊 TypeOrmModule в AppModule. 那些。 你的 AppModule 看起來像這樣：
應用程序模塊.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 {}正如您所注意到的，在方法中 forRoot 與 ormconfig.ts 文件中一樣傳遞與數據庫相同的配置
最後一點仍然存在——在 package.json 中添加一些使用 TypeORM 的任務。 事實上，CLI 是用 javascript 編寫的，運行在 nodejs 環境中。 但是，我們所有的模型和遷移都將用打字稿編寫。 因此，有必要在使用 CLI 之前轉換我們的遷移和模型。 為此，我們需要 ts-node 包：
yarn add -D ts-node
之後，將必要的命令添加到 package.json 中：
"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"第一個命令 typeorm 添加一個 ts-node 包裝器來啟動 TypeORM cli。 其餘命令是方便的快捷方式，作為開發人員，您幾乎每天都會用到它們：
migration:generate - 根據模型的變化創建遷移。
migration:create - 創建一個空遷移。
migration:run - 開始遷移。
好吧，現在一切都確定了，我們已經添加了必要的包，將應用程序配置為從 cli 和應用程序本身使用數據庫，還啟動了 DBMS。 是時候向我們的應用程序添加邏輯了。
安裝用於創建 CRUD 的包
僅使用 Nest，您可以創建一個允許您創建、讀取、更新和刪除實體的 API。 這樣的解決方案將盡可能靈活，但在某些情況下會是多餘的。 例如，如果您需要快速創建原型，那麼您通常可以為了開發速度而犧牲靈活性。 許多框架通過描述特定實體的數據模型來提供生成 CRUD 的功能。 Nest也不例外！ 此功能由包提供 . 它的可能性非常有趣：
- 易於安裝和配置；
- 獨立於 DBMS；
- 強大的查詢語言，具有過濾、分頁、排序、加載關係和嵌套實體、緩存等功能；
- 用於為前端生成請求的包；
- 輕鬆重新定義控制器方法；
- 小配置；
- 大搖大擺的文檔支持。
該功能分為幾個包：
- - 裝飾者提供的基礎包 () 用於路由生成、配置和驗證；
- - 一個提供在前端使用的查詢構建器/解析器的包；
- - 一個與 TypeORM 集成的包，它提供了一個基本的 TypeOrmCrudService 服務，帶有 CRUD 方法，用於處理數據庫中的實體。
對於本指南，我們需要包 jsx/crud 和 jsx/crud 類型形式。 首先，讓我們把它們
yarn add @nestjsx/crud class-transformer class-validator套餐 и 在此應用程序中，需要分別對轉換模型實例和驗證傳入請求的規則進行聲明性描述。 這些包來自同一作者，因此接口相似。
直接實現CRUD
作為模型的示例，我們將採用用戶列表。 用戶將具有以下字段： id, username, displayName, email. id - 自動增量字段， email и username - 獨特的領域。 一切都很簡單！ 它仍然以 Nest 應用程序的形式實現我們的想法。
首先你需要創建一個模塊 users誰將負責與用戶合作。 讓我們使用 NestJS 的 cli，在我們項目的根目錄中，我們將執行命令 nest g module users.
嵌套 g 模塊用戶
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)在這個模塊中，我們將添加 entities 文件夾，我們將在其中放置該模塊的模型。 特別是，讓我們在此處添加 user.entity.ts 文件，其中包含用戶模型的描述：
用戶.entity.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;
}為了讓我們的應用程序“看到”這個模型，有必要在模塊中 UsersModule 進口 TypeOrmModule 以下內容：
用戶.module.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 {}所以我們在這裡導入 TypeOrmModule，其中作為方法參數 forFeature 指定與此模塊相關的模型列表。
它仍然是在數據庫中創建相應的實體。 為了這些目的，使用了遷移機制。 要基於模型更改創建遷移，請運行命令 npm run migration:generate -- CreateUserTable:
劇透標題
$ npm run migration:generate -- CreateUserTable
Migration /home/dmitrii/projects/nest-rest/migrations/1563346135367-CreateUserTable.ts has been generated successfully.
Done in 1.96s.我們不必手動編寫遷移，一切都神奇地發生了。 這不是奇蹟嗎！ 然而，這還不是全部。 我們看一下生成的遷移文件：
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"`);
}
}可以看到，不僅自動生成了開始遷移的方法，還自動生成了回滾的方法。 極好的！
它仍然只是滾動此遷移。 這是通過以下命令完成的：
npm run migration:run.就是這樣，現在架構更改已遷移到數據庫。
接下來，我們將創建一個服務，該服務將負責與用戶合作並將其繼承自 TypeOrmCrudService. 在我們的例子中，有必要將感興趣的實體的存儲庫傳遞給父構造函數的參數 User 存儲庫。
用戶.service.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);
}
}我們需要控制器中的這項服務 users. 要創建控制器，請在控制台中鍵入 nest g controller users/controllers/users
nest g 控制器用戶/控制器/用戶
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)打開這個控制器並編輯以添加一些魔法 jsx/crud. 每班 UsersController 讓我們像這樣添加一個裝飾器：
@Crud({
model: {
type: User
}
}) 是一個裝飾器，它將必要的方法添加到控制器以使用模型。 模型類型在字段中指示 model.type 裝飾器配置。
第二步，實現接口 CrudController<User>. “組裝”的控制器代碼如下所示：
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){}
}這就是全部！ 現在控制器支持模型的整套操作！ 不信？ 讓我們試試我們的應用程序吧！
TestMace 中的腳本請求
為了測試我們的服務，我們將使用 IDE 來處理 API . 為什麼要測試 Mac？ 與同類產品相比，具有以下優點：
- 強大的變量處理。 目前，有幾種類型的變量，每一種都有特定的作用：內置變量、動態變量、環境變量。 每個變量都屬於某個節點，支持繼承機制；
- 無需編程即可輕鬆編寫腳本。 這將在下面討論；
- 允許您在版本控制系統中保存項目的人類可讀格式；
- 自動完成，語法高亮，高亮變量值；
- API 描述支持，能夠從 Swagger 導入。
讓我們用命令啟動我們的服務器 npm start 並嘗試訪問用戶列表。 根據我們的控制器配置判斷，用戶列表可以從 url localhost:3000/users 獲得。 讓我們請求這個 url。
運行TestMace後，可以看到這個界面：
左上角是帶有根節點的項目樹 . 讓我們嘗試創建第一個請求來獲取用戶列表。 為此，我們將創建 節點。 這是在項目節點的上下文菜單中完成的。 添加節點 -> RequestStep.
將 localhost:3000/users 粘貼到 URL 字段並運行請求。 我們在響應正文中得到 200 個帶有空數組的代碼。 這是可以理解的，我們還沒有添加任何人。
讓我們創建一個包含以下步驟的腳本：
- 用戶創建；
- 通過新創建用戶的id查詢；
- 按步驟 1 中創建的用戶 ID 刪除。
所以我們走吧。 為了方便起見，讓我們創建一個節點 . 事實上，這只是一個文件夾，我們將在其中保存整個腳本。 要創建文件夾節點，請在項目節點的上下文菜單中選擇 添加節點 -> 文件夾. 讓我們調用節點 檢查創建. 節點內部 檢查創建 讓我們創建第一個創建用戶的請求。 讓我們命名新創建的節點 創建用戶. 也就是說，此時節點層次結構將如下所示：
讓我們轉到打開的選項卡 創建用戶 節點。 讓我們為請求輸入以下參數：
- 請求類型 - POST
- 網址 - localhost:3000/用戶
- 主體 - 具有值的 JSON
{"email": "[email protected]", "displayName": "New user", "username": "user"}
讓我們執行這個請求。 我們的應用程序說條目已經創建。
好吧，讓我們檢查一下這個事實。 為了在後續步驟中使用創建的用戶的id進行操作，必須保存該參數。 這種機制非常適合這一點。 . 讓我們看看我們如何使用我們的示例與他們合作。 在響應的解析選項卡中，在上下文菜單中的 id 節點處，選擇項目 分配給變量. 必須在對話框中指定以下參數：
- 節點 - 在哪個祖先中創建一個動態變量。 讓我們選擇 檢查創建
- 變量名 是這個變量的名字。 讓我們打電話
userId.
以下是創建動態變量的過程：
現在，每次執行此查詢時，都會更新動態變量的值。 自從動態變量支持層次繼承機制，變量 userId 將在後代中可用 檢查創建 任何嵌套級別的節點。
在下一個請求中，這個變量將對我們有用。 即，我們將請求一個新創建的用戶。 作為節點的孩子 檢查創建 我們將創建一個請求 檢查是否存在 帶參數 url 等於 localhost:3000/users/${$dynamicVar.userId}. 查看施工 ${variable_name} 正在獲取變量的值。 因為我們有一個動態變量，然後要獲取它，您需要引用該對象 $dynamicVar，即完全訪問動態變量 userId 看起來像這樣 ${$dynamicVar.userId}. 讓我們執行請求並確保正確請求數據。
最後一點仍然是 - 提出刪除請求。 我們不僅需要它來檢查刪除操作，而且，可以說，在數據庫中清理我們自己之後，因為電子郵件和用戶名字段是唯一的。 因此，在 check-create 節點中，我們將使用以下參數創建一個 delete-user 請求
- 請求類型 - 刪除
- 網址 —
localhost:3000/users/${$dynamicVar.userId}
我們發射。 我們等。 享受結果）
好了，現在我們可以隨時完整地運行這個腳本了。 要運行腳本，請從上下文菜單中選擇 檢查創建 結點 跑.
腳本中的節點會依次執行
您可以通過運行將此腳本保存到您的項目中 文件 -> 保存項目.
結論
所用工具的所有芯片根本無法適應本文的格式。 至於罪魁禍首——包裹 jsx/crud - 以下主題仍未發現：
- 模型的自定義驗證和轉換；
- 強大的查詢語言，前端使用方便；
- 重新定義並向 crud 控制器添加新方法；
- 大搖大擺的支持；
- 緩存管理。
然而，即使是文章中描述的內容也足以理解，即使像 NestJS 這樣的企業框架也有用於快速應用程序原型製作的工具。 還有這麼酷的IDE 讓您保持既定的步伐。
本文的源代碼以及項目 , 在存儲庫中可用 . 打開一個項目 在應用程序中執行就足夠了 文件 -> 打開項目.
來源： www.habr.com