目前，REST API 已成为 Web 应用程序开发的标准，允许您将开发分解为独立的部分。对于 UI，目前使用各种流行的框架，例如 Angular、React、Vue 等。后端开发人员可以从种类繁多的语言和框架中进行选择。今天我想谈谈这样一个框架巢穴. 我们在测试锤我们积极将其用于内部项目。使用嵌套和包 @nestjsx/crud，我们将创建一个简单的 CRUD 应用程序。

为什么选择 NestJS

最近，JavaScript 社区出现了相当多的后端框架。如果在功能方面它们提供了类似于 Nest 的机会，那么它肯定会在一件事上获胜——这就是架构。以下 NestJS 功能允许您创建工业应用程序并将开发扩展到大型团队：

使用 TypeScript 作为主要开发语言。尽管 NestJS 支持 JavaScript，但某些功能可能无法使用，尤其是涉及到第三方包时；
存在 DI 容器，它允许您创建松散耦合的组件；
框架本身的功能分为独立的可互换组件。例如，在引擎盖下作为一个框架可以用作特快和固定, 开箱即用的嵌套数据库提供了绑定打字机, 猫鼬, 续集;
NestJS 是平台独立的，支持 REST、GraphQL、Websockets、gRPC 等。

该框架本身受到 Angular 前端框架的启发，并且在概念上与它有很多共同点。

安装 NestJS 并部署项目

Nest 包含一个包巢/cli，可以让你快速部署一个基本的应用框架。全局安装这个包：

npm install --global @nest/cli

安装后，我们将生成我们应用程序的基本框架，名称为 嵌套资源吨。这是使用命令完成的 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

我们将选择 yarn 作为我们的包管理器。
现在，您可以使用以下命令启动服务器 npm start 去地址 http://localhost:3000 你可以看到主页。然而，这不是我们来这里的目的，我们正在继续前进。

设置数据库工作

作为本文的 DBMS，我选择了 PostrgreSQL。没有任何关于口味的争议，在我看来，这是具有所有必要功能的最成熟的 DBMS。如前所述，Nest 提供了与各种用于处理数据库的包的集成。因为由于我的选择落在了 PostgreSQL 上，因此选择 TypeORM 作为 ORM 是合乎逻辑的。安装与数据库集成所需的包：

yarn add typeorm @nestjs/typeorm pg

按顺序，每个包的用途：

typeorm - 直接来自 ORM 本身的包；
@nestjs/typeorm - NestJS 的 TypeORM 包。添加用于导入项目模块的模块，以及一组辅助装饰器；
pg 是与 PostgreSQL 一起工作的驱动程序。

好的，包已经安装好了，现在你需要启动数据库本身。为了部署基础，我将使用包含以下内容的 docker-compose.yml：

泊坞窗，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

如您所见，此文件配置了 2 个容器的启动：

db 是直接带有数据库的容器。在我们的例子中，使用 postgresql 版本 11.2；
管理员 - 数据库管理员。提供用于查看和管理数据库的 Web 界面。

为了使用 tcp 连接，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

就是这样，您可以使用命令运行容器 docker-compose up -d. 或者在单独的控制台中使用命令 docker-compose up.

因此，安装了软件包，启动了基础，剩下的就是让他们彼此成为朋友。为此，将 ormconfig.js 文件添加到项目的根目录，内容如下：

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"
}
}

此配置将用于 cli typeorm。

让我们仔细看看这个配置。在第 3 行和第 4 行中，我们从环境变量中获取用户名和密码。当您有多个环境（开发、阶段、生产等）时，这很方便。默认用户名是 postgres，密码是 example。否则，配置是微不足道的，所以我们将只关注最有趣的参数：

synchronize 指定数据库模式是否应在应用程序启动时自动创建。请小心使用此选项，不要在生产中使用它，否则您将丢失数据。此选项在开发和调试应用程序时很有用。作为此选项的替代方法，您可以使用以下命令 schema:sync 来自 CLI TypeORM。
dropSchema - 每次建立连接时删除架构。此外，与前一个选项一样，此选项应仅在应用程序的开发和调试期间使用。
entities - 查找模型描述的路径。请注意，支持掩码搜索。
cli.entitiesDir 是默认情况下应添加从 CLI TypeORM 创建的模型的目录。

为了让我们在 Nest 应用程序中使用 TypeORM 的所有功能，我们需要导入模块 TypeOrmModule в AppModule. 那些。你的 AppModule 看起来像这样：

应用程序模块.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 与 ormconfig.ts 文件中一样传递与数据库相同的配置

最后一点仍然存在——在 package.json 中添加一些使用 TypeORM 的任务。事实上，CLI 是用 javascript 编写的，运行在 nodejs 环境中。但是，我们所有的模型和迁移都将用打字稿编写。因此，有必要在使用 CLI 之前转换我们的迁移和模型。为此，我们需要 ts-node 包：

yarn add -D ts-node

之后，将必要的命令添加到 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"

第一个命令 typeorm 添加一个 ts-node 包装器来启动 TypeORM cli。其余命令是方便的快捷方式，作为开发人员，您几乎每天都会用到它们：
migration:generate - 根据模型的变化创建迁移。
migration:create - 创建一个空迁移。
migration:run - 开始迁移。
好吧，现在一切都确定了，我们已经添加了必要的包，将应用程序配置为从 cli 和应用程序本身使用数据库，还启动了 DBMS。是时候向我们的应用程序添加逻辑了。

安装用于创建 CRUD 的包

仅使用 Nest，您可以创建一个允许您创建、读取、更新和删除实体的 API。这样的解决方案将尽可能灵活，但在某些情况下会是多余的。例如，如果您需要快速创建原型，那么您通常可以为了开发速度而牺牲灵活性。许多框架通过描述特定实体的数据模型来提供生成 CRUD 的功能。 Nest也不例外！此功能由包提供 @nestjsx/crud. 它的可能性非常有趣：

易于安装和配置；
独立于 DBMS；
强大的查询语言，具有过滤、分页、排序、加载关系和嵌套实体、缓存等功能；
用于为前端生成请求的包；
轻松重新定义控制器方法；
小配置；
大摇大摆的文档支持。

该功能分为几个包：

@nestjsx/crud - 装饰者提供的基础包原油() 用于路由生成、配置和验证；
@nestjsx/crud 请求 - 一个提供在前端使用的查询构建器/解析器的包；
@nestjsx/crud-typeform - 一个与 TypeORM 集成的包，它提供了一个基本的 TypeOrmCrudService 服务，带有 CRUD 方法，用于处理数据库中的实体。

对于本指南，我们需要包巢jsx/crud 和巢jsx/crud 类型形式。首先，让我们把它们

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

包类转换器 и 类验证器在此应用程序中，需要分别对转换模型实例和验证传入请求的规则进行声明性描述。这些包来自同一作者，因此接口相似。

直接实现CRUD

作为模型的示例，我们将采用用户列表。用户将具有以下字段： id, username, displayName, email. id - 自动增量字段， email и username - 独特的领域。一切都很简单！它仍然以 Nest 应用程序的形式实现我们的想法。
首先你需要创建一个模块 users谁将负责与用户合作。让我们使用 NestJS 的 cli，在我们项目的根目录中，我们将执行命令 nest g module users.

嵌套 g 模块用户

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)

在这个模块中，我们将添加 entities 文件夹，我们将在其中放置该模块的模型。特别是，让我们在此处添加 user.entity.ts 文件，其中包含用户模型的描述：

用户.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;
}

为了让我们的应用程序“看到”这个模型，有必要在模块中 UsersModule 进口 TypeOrmModule 以下内容：

用户.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 {}

所以我们在这里导入 TypeOrmModule，其中作为方法参数 forFeature 指定与此模块相关的模型列表。

它仍然是在数据库中创建相应的实体。为了这些目的，使用了迁移机制。要基于模型更改创建迁移，请运行命令 npm run migration:generate -- CreateUserTable:

剧透标题

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

我们不必手动编写迁移，一切都神奇地发生了。这不是奇迹吗！然而，这还不是全部。我们看一下生成的迁移文件：

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，不仅自动生成了开始迁移的方法，还自动生成了回滚的方法。极好的！
它仍然只是滚动此迁移。这是通过以下命令完成的：

npm run migration:run.

就是这样，现在架构更改已迁移到数据库。
接下来，我们将创建一个服务，该服务将负责与用户合作并将其继承自 TypeOrmCrudService. 在我们的例子中，有必要将感兴趣的实体的存储库传递给父构造函数的参数 User 存储库。

用户.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);
}
}

我们需要控制器中的这项服务 users. 要创建控制器，请在控制台中键入 nest g controller users/controllers/users

nest g 控制器用户/控制器/用户

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)

打开这个控制器并编辑以添加一些魔法巢jsx/crud. 每班 UsersController 让我们像这样添加一个装饰器：

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

原油是一个装饰器，它将必要的方法添加到控制器以使用模型。模型类型在字段中指示 model.type 装饰器配置。
第二步，实现接口 CrudController<User>. “组装”的控制器代码如下所示：

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){}
}

这就是全部！现在控制器支持模型的整套操作！不信？让我们试试我们的应用程序吧！

TestMace 中的脚本请求

为了测试我们的服务，我们将使用 IDE 来处理 API 测试锤. 为什么要测试 Mac？与同类产品相比，具有以下优点：

强大的变量处理。目前，有几种类型的变量，每一种都有特定的作用：内置变量、动态变量、环境变量。每个变量都属于某个节点，支持继承机制；
无需编程即可轻松编写脚本。这将在下面讨论；
允许您在版本控制系统中保存项目的人类可读格式；
自动完成，语法高亮，高亮变量值；
API 描述支持，能够从 Swagger 导入。

让我们用命令启动我们的服务器 npm start 并尝试访问用户列表。根据我们的控制器配置判断，用户列表可以从 url localhost:3000/users 获得。让我们请求这个 url。
运行TestMace后，可以看到这个界面：

左上角是带有根节点的项目树项目. 让我们尝试创建第一个请求来获取用户列表。为此，我们将创建请求步骤节点。这是在项目节点的上下文菜单中完成的。 添加节点 -> RequestStep.

将 localhost:3000/users 粘贴到 URL 字段并运行请求。我们在响应正文中得到 200 个带有空数组的代码。这是可以理解的，我们还没有添加任何人。
让我们创建一个包含以下步骤的脚本：

用户创建；
通过新创建用户的id查询；
按步骤 1 中创建的用户 ID 删除。

所以我们走吧。为了方便起见，让我们创建一个节点夹. 事实上，这只是一个文件夹，我们将在其中保存整个脚本。要创建文件夹节点，请在项目节点的上下文菜单中选择 添加节点 -> 文件夹. 让我们调用节点 检查创建. 节点内部 检查创建 让我们创建第一个创建用户的请求。让我们命名新创建的节点 创建用户. 也就是说，此时节点层次结构将如下所示：

让我们转到打开的选项卡 创建用户 节点。让我们为请求输入以下参数：

请求类型 - POST
网址 - localhost:3000/用户
主体 - 具有值的 JSON {"email": "[email protected]", "displayName": "New user", "username": "user"}

让我们执行这个请求。我们的应用程序说条目已经创建。

好吧，让我们检查一下这个事实。为了在后续步骤中使用创建的用户的id进行操作，必须保存该参数。这种机制非常适合这一点。动态变量. 让我们看看我们如何使用我们的示例与他们合作。在响应的解析选项卡中，在上下文菜单中的 id 节点处，选择项目 分配给变量. 必须在对话框中指定以下参数：

Node - 在哪个祖先中创建一个动态变量。让我们选择 检查创建
变量名 是这个变量的名字。让我们打电话 userId.

以下是创建动态变量的过程：

现在，每次执行此查询时，都会更新动态变量的值。自从动态变量支持层次继承机制，变量 userId 将在后代中可用 检查创建 任何嵌套级别的节点。
在下一个请求中，这个变量将对我们有用。即，我们将请求一个新创建的用户。作为节点的孩子 检查创建 我们将创建一个请求 检查是否存在 带参数 url 等于 localhost:3000/users/${$dynamicVar.userId}. 查看施工 ${variable_name} 正在获取变量的值。因为我们有一个动态变量，然后要获取它，您需要引用该对象 $dynamicVar，即完全访问动态变量 userId 看起来像这样 ${$dynamicVar.userId}. 让我们执行请求并确保正确请求数据。
最后一点仍然是 - 提出删除请求。我们不仅需要它来检查删除操作，而且，可以说，在数据库中清理我们自己之后，因为电子邮件和用户名字段是唯一的。因此，在 check-create 节点中，我们将使用以下参数创建一个 delete-user 请求

请求类型 - 删除
网址 - localhost:3000/users/${$dynamicVar.userId}

我们发射。我们等。享受结果）

好了，现在我们可以随时完整地运行这个脚本了。要运行脚本，请从上下文菜单中选择 检查创建 结点运行.

脚本中的节点会依次执行
您可以通过运行将此脚本保存到您的项目中 文件 -> 保存项目.

结论

所用工具的所有芯片根本无法适应本文的格式。至于罪魁祸首——包裹巢jsx/crud - 以下主题仍未发现：

模型的自定义验证和转换；
强大的查询语言，前端使用方便；
重新定义并向 crud 控制器添加新方法；
大摇大摆的支持；
缓存管理。

然而，即使是文章中描述的内容也足以理解，即使像 NestJS 这样的企业框架也有用于快速应用程序原型制作的工具。还有这么酷的IDE 测试锤让您保持既定的步伐。

本文的源代码以及项目测试锤, 在存储库中可用 https://github.com/TestMace/nest-rest. 打开一个项目测试锤在应用程序中执行就足够了 文件 -> 打开项目.

来源： habr.com

使用 nest、@nestjsx/crud 和 TestMace 快速创建 CRUD

为什么选择 NestJS

安装 NestJS 并部署项目

设置数据库工作

安装用于创建 CRUD 的包

直接实现CRUD

TestMace 中的脚本请求

结论

添加评论取消回复

使用 nest、@nestjsx/crud 和 TestMace 快速创建 CRUD

为什么选择 NestJS

安装 NestJS 并部署项目

设置数据库工作

安装用于创建 CRUD 的包

直接实现CRUD

TestMace 中的脚本请求

结论

添加评论 取消回复

添加评论取消回复