Class ReadPreference

constructor

• new ReadPreference(mode, tags?, options?): ReadPreference

• Parameters

  • mode: ReadPreferenceMode

    A string describing the read preference mode (primary|primaryPreferred|secondary|secondaryPreferred|nearest)描述读取首选项模式的字符串（primary|primaryPreferred|secondary|secondaryPreferred|nearest）。

  • Optional tags: TagSet[]

    A tag set used to target reads to members with the specified tag(s). 一个标记集，用于将读取目标指向具有指定标记的成员。tagSet is not available if using read preference mode primary.如果使用读取首选项模式主，则tagSet不可用。

  • Optional options: ReadPreferenceOptions

    Additional read preference options其他读取首选项

  Returns ReadPreference

Optional hedge

Optional maxStalenessSeconds

Optional minWireVersion

mode

Optional tags

Static NEAREST

Static PRIMARY

Static PRIMARY_PREFERRED

Static SECONDARY

Static SECONDARY_PREFERRED

Static nearest

Static primary

Static primaryPreferred

Static secondary

Static secondaryPreferred

preference

• get preference(): ReadPreferenceMode

• Returns ReadPreferenceMode

equals

• equals(readPreference): boolean

• Check if the two ReadPreferences are equivalent检查两个ReadPreferences是否等效

  Parameters

  • readPreference: ReadPreference

    The read preference with which to check equality用于检查相等性的读取首选项

  Returns boolean

isValid

• isValid(mode?): boolean

• Validate if a mode is legal验证模式是否合法

  Parameters

  • Optional mode: string

    The string representing the read preference mode.表示读取首选项模式的字符串。

  Returns boolean

secondaryOk

• secondaryOk(): boolean

• Indicates that this readPreference needs the "SecondaryOk" bit when sent over the wire指示此readPreference在通过导线发送时需要“SecondaryOk”位

  Returns boolean

  See

  /v7.0/reference/mongodb-wire-protocol/#op-query

toJSON

• toJSON(): Document

• Return JSON representation返回JSON表示

  Returns Document

Static fromOptions

• fromOptions(options?): undefined | ReadPreference

• Construct a ReadPreference given an options object.在给定选项对象的情况下构造ReadPreference。

  Parameters

  • Optional options: ReadPreferenceFromOptions

    The options object from which to extract the read preference.从中提取读取首选项的选项对象。

  Returns undefined | ReadPreference

Static fromString

• fromString(mode): ReadPreference

• Parameters

  • mode: string

  Returns ReadPreference

Static isValid

• isValid(mode): boolean

• Validate if a mode is legal验证模式是否合法

  Parameters

  • mode: string

    The string representing the read preference mode.表示读取首选项模式的字符串。

  Returns boolean

Static translate

• translate(options): ReadPreferenceLikeOptions

• Replaces options.readPreference with a ReadPreference instance用ReadPreference实例替换options.readPreference

  Parameters

  • options: ReadPreferenceLikeOptions

  Returns ReadPreferenceLikeOptions