Connection Options

What is ConnectionOptions

Connection options is a connection configuration you pass to createConnection or define in ormconfig file. Different databases have their own specific connection options.

Common connection options

  • type - Database type. You must specify what database engine you use.Possible values are “mysql”, “postgres”, “cockroachdb”, “mariadb”, “sqlite”, “cordova”, “nativescript”,“oracle”, “mssql”, “mongodb”, “sqljs”, “react-native”.This option is required.

  • name - Connection name. You’ll use it to get connection you need using getConnection(name: string)or ConnectionManager.get(name: string).Connection names for different connections cannot be same - they all must be unique.If connection name is not given then it will be called “default”.

  • extra - Extra connection options to be passed to the underlying driver.Use it if you want to pass extra settings to underlying database driver.

  • entities - Entities to be loaded and used for this connection.Accepts both entity classes and directories paths to load from.Directories support glob patterns.Example: entities: [Post, Category, "entity/*.js", "modules/**/entity/*.js"].Learn more about Entities.

  • subscribers - Subscribers to be loaded and used for this connection.Accepts both entity classes and directories to load from.Directories support glob patterns.Example: subscribers: [PostSubscriber, AppSubscriber, "subscriber/*.js", "modules/**/subscriber/*.js"].Learn more about Subscribers.

  • entitySchemas - Entity schemas to be loaded and used for this connection.Accepts both entity schema classes and directories to load from.Directories support glob patterns.Example: entitySchemas: [PostSchema, CategorySchema, "entity-schema/*.json", "modules/**/entity-schema/*.json"].Learn more about Entity Schemas.

  • migrations - Migrations to be loaded and used for this connection.Accepts both migration classes and directories to load from.Directories support glob patterns.Example: migrations: [FirstMigration, SecondMigration, "migration/*.js", "modules/**/migration/*.js"].Learn more about Migrations.

  • logging - Indicates if logging is enabled or not.If set to true then query and error logging will be enabled.You can also specify different types of logging to be enabled, for example ["query", "error", "schema"].Learn more about Logging.

  • logger - Logger to be used for logging purposes. Possible values are “advanced-console”, “simple-console” and “file”.Default is “advanced-console”. You can also specify a logger class that implements Logger interface.Learn more about Logging.

  • maxQueryExecutionTime - If query execution time exceed this given max execution time (in milliseconds)then logger will log this query.

  • namingStrategy - Naming strategy to be used to name tables and columns in the database.Learn more about Naming strategies.

  • entityPrefix - Prefixes with the given string all tables (or collections) on this database connection.

  • dropSchema - Drops the schema each time connection is being established.Be careful with this option and don’t use this in production - otherwise you’ll lose all production data.This option is useful during debug and development.

  • synchronize - Indicates if database schema should be auto created on every application launch.Be careful with this option and don’t use this in production - otherwise you can lose production data.This option is useful during debug and development.As an alternative to it, you can use CLI and run schema:sync command.Note that for MongoDB database it does not create schema, because MongoDB is schemaless.Instead, it syncs just by creating indices.

  • migrationsRun - Indicates if migrations should be auto run on every application launch.As an alternative, you can use CLI and run migration:run command.

  • migrationsTableName - Name of the table in the database which is going to contain information about executed migrations.By default this table is called “migrations”.

  • cache - Enables entity result caching. You can also configure cache type and other cache options here.Read more about caching here.

  • cli.entitiesDir - Directory where entities should be created by default by CLI.

  • cli.migrationsDir - Directory where migrations should be created by default by CLI.

  • cli.subscribersDir - Directory where subscribers should be created by default by CLI.

mysql / mariadb connection options

  • url - Connection url where perform connection to. Please note that other connection options will override parameters set from url.

  • host - Database host.

  • port - Database host port. Default mysql port is 3306.

  • username - Database username.

  • password - Database password.

  • database - Database name.

  • charset - The charset for the connection. This is called “collation” in the SQL-level of MySQL(like utf8_general_ci). If a SQL-level charset is specified (like utf8mb4) then the default collation for that charset is used. (Default: UTF8_GENERAL_CI).

  • timezone - the timezone configured on the MySQL server. This is used to typecast server date/timevalues to JavaScript Date object and vice versa. This can be local, Z, or an offset in the form+HH:MM or -HH:MM. (Default: local)

  • connectTimeout - The milliseconds before a timeout occurs during the initial connection to the MySQL server.(Default: 10000)

  • acquireTimeout - The milliseconds before a timeout occurs during the initial connection to the MySql server. It differs from connectTimeout as it governs the TCP connection timeout where as connectTimeout does not. (default: 10000)

  • insecureAuth - Allow connecting to MySQL instances that ask for the old (insecure) authentication method.(Default: false)

  • supportBigNumbers - When dealing with big numbers (BIGINT and DECIMAL columns) in the database,you should enable this option (Default: true)

  • bigNumberStrings - Enabling both supportBigNumbers and bigNumberStrings forces big numbers(BIGINT and DECIMAL columns) to be always returned as JavaScript String objects (Default: true).Enabling supportBigNumbers but leaving bigNumberStrings disabled will return big numbers as Stringobjects only when they cannot be accurately represented withJavaScript Number objects(which happens when they exceed the [-2^53, +2^53] range), otherwise they will be returned asNumber objects. This option is ignored if supportBigNumbers is disabled.

  • dateStrings - Force date types (TIMESTAMP, DATETIME, DATE) to be returned as strings rather thaninflated into JavaScript Date objects. Can be true/false or an array of type names to keep as strings.(Default: false)

  • debug - Prints protocol details to stdout. Can be true/false or an array of packet type names thatshould be printed. (Default: false)

  • trace - Generates stack traces on Error to include call site of library entrance (“long stack traces”).Slight performance penalty for most calls. (Default: true)

  • multipleStatements - Allow multiple mysql statements per query. Be careful with this, it could increase the scopeof SQL injection attacks. (Default: false)

  • flags - List of connection flags to use other than the default ones. It is also possible to blacklist default ones.For more information, check Connection Flags.

  • ssl - object with ssl parameters or a string containing the name of ssl profile.See SSL options.

postgres / cockroachdb connection options

  • url - Connection url where perform connection to. Please note that other connection options will override parameters set from url.

  • host - Database host.

  • port - Database host port. Default postgres port is 5432.

  • username - Database username.

  • password - Database password.

  • database - Database name.

  • schema - Schema name. Default is “public”.

  • ssl - Object with ssl parameters. See TLS/SSL.

  • uuidExtension - The Postgres extension to use when generating UUIDs. Defaults to uuid-ossp. Can be changed to pgcrypto if the uuid-ossp extension is unavailable.

  • poolErrorHandler - A function that get’s called when underlying pool emits 'error' event. Takes single parameter (error instance) and defaults to logging with warn level.

sqlite connection options

  • database - Database path. For example “./mydb.sql”

cordova connection options

react-native connection options

nativescript connection options

  • database - Database name

mssql connection options

  • url - Connection url where perform connection to. Please note that other connection options will override parameters set from url.

  • host - Database host.

  • port - Database host port. Default mssql port is 1433.

  • username - Database username.

  • password - Database password.

  • database - Database name.

  • schema - Schema name. Default is “public”.

  • domain - Once you set domain, the driver will connect to SQL Server using domain login.

  • connectionTimeout - Connection timeout in ms (default: 15000).

  • requestTimeout - Request timeout in ms (default: 15000). NOTE: msnodesqlv8 driver doesn’t supporttimeouts < 1 second.

  • stream - Stream recordsets/rows instead of returning them all at once as an argument of callback (default: false).You can also enable streaming for each request independently (request.stream = true). Always set to true if you plan towork with a large amount of rows.

  • pool.max - The maximum number of connections there can be in the pool (default: 10).

  • pool.min - The minimum of connections there can be in the pool (default: 0).

  • pool.maxWaitingClients - maximum number of queued requests allowed, additional acquire calls will be callback withan err in a future cycle of the event loop.

  • pool.testOnBorrow - should the pool validate resources before giving them to clients. Requires that eitherfactory.validate or factory.validateAsync to be specified.

  • pool.acquireTimeoutMillis - max milliseconds an acquire call will wait for a resource before timing out.(default no limit), if supplied should non-zero positive integer.

  • pool.fifo - if true the oldest resources will be first to be allocated. If false the most recently released resourceswill be the first to be allocated. This in effect turns the pool’s behaviour from a queue into a stack. boolean,(default true).

  • pool.priorityRange - int between 1 and x - if set, borrowers can specify their relative priority in the queue if noresources are available. see example. (default 1).

  • pool.autostart - boolean, should the pool start creating resources etc once the constructor is called, (default true).

  • pool.evictionRunIntervalMillis - How often to run eviction checks. Default: 0 (does not run).

  • pool.numTestsPerRun - Number of resources to check each eviction run. Default: 3.

  • pool.softIdleTimeoutMillis - amount of time an object may sit idle in the pool before it is eligible for eviction bythe idle object evictor (if any), with the extra condition that at least “min idle” object instances remain in the pool.Default -1 (nothing can get evicted).

  • pool.idleTimeoutMillis - the minimum amount of time that an object may sit idle in the pool before it is eligible foreviction due to idle time. Supersedes softIdleTimeoutMillis. Default: 30000.

    • pool.errorHandler - A function that get’s called when underlying pool emits 'error' event. Takes single parameter (error instance) and defaults to logging with warn level.

  • options.fallbackToDefaultDb - By default, if the database requestion by options.database cannot be accessed, the connectionwill fail with an error. However, if options.fallbackToDefaultDb is set to true, then the user’s default database willbe used instead (Default: false).

  • options.enableAnsiNullDefault - If true, SET ANSI_NULL_DFLT_ON ON will be set in the initial sql. This means newcolumns will be nullable by default. See the T-SQL documentationfor more details. (Default: true).

  • options.cancelTimeout - The number of milliseconds before the cancel (abort) of a request is considered failed (default: 5000).

  • options.packetSize - The size of TDS packets (subject to negotiation with the server). Should be a power of 2. (default: 4096).

  • options.useUTC - A boolean determining whether to pass time values in UTC or local time. (default: true).

  • options.abortTransactionOnError - A boolean determining whether to rollback a transaction automatically if anyerror is encountered during the given transaction’s execution. This sets the value for SET XACT_ABORT during theinitial SQL phase of a connection (documentation).

  • options.localAddress - A string indicating which network interface (ip address) to use when connecting to SQL Server.

  • options.useColumnNames - A boolean determining whether to return rows as arrays or key-value collections. (default: false).

  • options.camelCaseColumns - A boolean, controlling whether the column names returned will have the first letterconverted to lower case (true) or not. This value is ignored if you provide a columnNameReplacer. (default: false).

  • options.isolationLevel - The default isolation level that transactions will be run with. The isolation levels areavailable from require('tedious').ISOLATION_LEVEL.

    • READ_UNCOMMITTED
    • READ_COMMITTED
    • REPEATABLE_READ
    • SERIALIZABLE

    • SNAPSHOT

      (default: READ_COMMITTED)

  • options.connectionIsolationLevel - The default isolation level for new connections. All out-of-transaction queriesare executed with this setting. The isolation levels are available from require('tedious').ISOLATION_LEVEL.

    • READ_UNCOMMITTED
    • READ_COMMITTED
    • REPEATABLE_READ
    • SERIALIZABLE

    • SNAPSHOT

      (default: READ_COMMITTED)

  • options.readOnlyIntent - A boolean, determining whether the connection will request read-only access from aSQL Server Availability Group. For more information, see here. (default: false).

  • options.encrypt - A boolean determining whether or not the connection will be encrypted. Set to true if you’reon Windows Azure. (default: false).

  • options.cryptoCredentialsDetails - When encryption is used, an object may be supplied that will be used for thefirst argument when calling tls.createSecurePair(default: {}).

  • options.rowCollectionOnDone - A boolean, that when true will expose received rows in Requests’ done* events.See done, doneInProcand doneProc. (default: false)

    Caution: If many rows are received, enabling this option could result in excessive memory usage.

  • options.rowCollectionOnRequestCompletion - A boolean, that when true will expose received rowsin Requests’ completion callback. See new Request. (default: false)

    Caution: If many rows are received, enabling this option could result in excessive memory usage.

  • options.tdsVersion - The version of TDS to use. If the server doesn’t support the specified version, a negotiated versionis used instead. The versions are available from require('tedious').TDS_VERSION.

    • 7_1
    • 7_2
    • 7_3_A
    • 7_3_B
    • 7_4

    (default: 7_4)

  • options.debug.packet - A boolean, controlling whether debug events will be emitted with text describing packetdetails (default: false).

  • options.debug.data - A boolean, controlling whether debug events will be emitted with text describing packet datadetails (default: false).

  • options.debug.payload - A boolean, controlling whether debug events will be emitted with text describing packetpayload details (default: false).

  • options.debug.token - A boolean, controlling whether debug events will be emitted with text describing token streamtokens (default: false).

mongodb connection options

  • url - Connection url where perform connection to. Please note that other connection options will override parameters set from url.

  • host - Database host.

  • port - Database host port. Default mongodb port is 27017.

  • database - Database name.

  • poolSize - Set the maximum pool size for each individual server or proxy connection.

  • ssl - Use ssl connection (needs to have a mongod server with ssl support). Default: false.

  • sslValidate - Validate mongod server certificate against ca (needs to have a mongod server with ssl support,2.4 or higher). Default: true.

  • sslCA - Array of valid certificates either as Buffers or Strings (needs to have a mongod server with ssl support,2.4 or higher).

  • sslCert - String or buffer containing the certificate we wish to present (needs to have a mongod server with sslsupport, 2.4 or higher)

  • sslKey - String or buffer containing the certificate private key we wish to present (needs to have a mongod serverwith ssl support, 2.4 or higher).

  • sslPass - String or buffer containing the certificate password (needs to have a mongod server with ssl support,2.4 or higher).

  • autoReconnect - Reconnect on error. Default: true.

  • noDelay - TCP Socket NoDelay option. Default: true.

  • keepAlive - The number of milliseconds to wait before initiating keepAlive on the TCP socket. Default: 30000.

  • connectTimeoutMS - TCP Connection timeout setting. Default: 30000.

  • socketTimeoutMS - TCP Socket timeout setting. Default: 360000.

  • reconnectTries - Server attempt to reconnect #times. Default: 30.

  • reconnectInterval - Server will wait #milliseconds between retries. Default: 1000.

  • ha - Turn on high availability monitoring. Default: true.

  • haInterval - Time between each replicaset status check. Default: 10000,5000.

  • replicaSet - The name of the replicaset to connect to.

  • acceptableLatencyMS - Sets the range of servers to pick when using NEAREST (lowest ping ms + the latency fence,ex: range of 1 to (1 + 15) ms). Default: 15.

  • secondaryAcceptableLatencyMS - Sets the range of servers to pick when using NEAREST (lowest ping ms + the latencyfence, ex: range of 1 to (1 + 15) ms). Default: 15.

  • connectWithNoPrimary - Sets if the driver should connect even if no primary is available. Default: false.

  • authSource - If the database authentication is dependent on another databaseName.

  • w - The write concern.

  • wtimeout - The write concern timeout value.

  • j - Specify a journal write concern. Default: false.

  • forceServerObjectId - Force server to assign _id values instead of driver. Default: false.

  • serializeFunctions - Serialize functions on any object. Default: false.

  • ignoreUndefined - Specify if the BSON serializer should ignore undefined fields. Default: false.

  • raw - Return document results as raw BSON buffers. Default: false.

  • promoteLongs - Promotes Long values to number if they fit inside the 53 bits resolution. Default: true.

  • promoteBuffers - Promotes Binary BSON values to native Node Buffers. Default: false.

  • promoteValues - Promotes BSON values to native types where possible, set to false to only receive wrapper types.Default: true.

  • domainsEnabled - Enable the wrapping of the callback in the current domain, disabled by default to avoid perf hit.Default: false.

  • bufferMaxEntries - Sets a cap on how many operations the driver will buffer up before giving up on getting aworking connection, default is -1 which is unlimited.

  • readPreference - The preferred read preference.

    • ReadPreference.PRIMARY
    • ReadPreference.PRIMARY_PREFERRED
    • ReadPreference.SECONDARY
    • ReadPreference.SECONDARY_PREFERRED
    • ReadPreference.NEAREST

  • pkFactory - A primary key factory object for generation of custom _id keys.

  • promiseLibrary - A Promise library class the application wishes to use such as Bluebird, must be ES6 compatible.

  • readConcern - Specify a read concern for the collection. (only MongoDB 3.2 or higher supported).

  • maxStalenessSeconds - Specify a maxStalenessSeconds value for secondary reads, minimum is 90 seconds.

  • appname - The name of the application that created this MongoClient instance. MongoDB 3.4 and newer will print thisvalue in the server log upon establishing each connection. It is also recorded in the slow query log and profilecollections

  • loggerLevel - Specify the log level used by the driver logger (error/warn/info/debug).

  • logger - Specify a customer logger mechanism, can be used to log using your app level logger.

  • authMechanism - Sets the authentication mechanism that MongoDB will use to authenticate the connection.

sql.js connection options

  • database: The raw UInt8Array database that should be imported.

  • sqlJsConfig: Optional initialize config for sql.js.

  • autoSave: Whether or not autoSave should be disabled. If set to true the database will be saved to the given file location (Node.js) or LocalStorage element (browser) when a change happens and location is specified. Otherwise autoSaveCallback can be used.

  • autoSaveCallback: A function that get’s called when changes to the database are made and autoSave is enabled. The function gets a UInt8Array that represents the database.

  • location: The file location to load and save the database to.

  • useLocalForage: Enables the usage of the localforage library (https://github.com/localForage/localForage) to save & load the database asynchronously from the indexedDB instead of using the synchron local storage methods in a browser environment. The localforage node module needs to be added to your project and the localforage.js should be imported in your page.

expo connection options

  • database - Name of the database. For example “mydb”.

Connection options example

Here is a small example of connection options for mysql:

  1. {
  2.     host: "localhost",
  3.     port: 3306,
  4.     username: "test",
  5.     password: "test",
  6.     database: "test",
  7.     logging: true,
  8.     synchronize: true,
  9.     entities: [
  10.         "entity/*.js"
  11.     ],
  12.     subscribers: [
  13.         "subscriber/*.js"
  14.     ],
  15.     entitySchemas: [
  16.         "schema/*.json"
  17.     ],
  18.     migrations: [
  19.         "migration/*.js"
  20.     ],
  21.     cli: {
  22.         entitiesDir: "entity",
  23.         migrationsDir: "migration",
  24.         subscribersDir: "subscriber"
  25.     }
  26. }