gitlab.goalongtravels.com/open-source/couchdb-golang

CouchDB-Golang

A Golang library for CouchDB 2.x, inspired by CouchDB-Python.

Features

• Resource : a simple wrapper for HTTP requests and error handling
• Server : CouchDB server instance
• Database : CouchDB database instance
• ViewResults : a representation of the results produced by design document views
• ViewDefinition : a definition of view stored in a specific design document
• Document : a representation of document object in database
• tools/replicate : a command-line tool for replicating

func (d *Database) Query(fields []string, selector string, sorts []string, limit, skip, index interface{}) ([]map[string]interface{}, error)

You can query documents using a conditional selector statement in Golang. It will converts to the corresponding JSON query string.

• selector: A filter string declaring which documents to return, formatted as a Golang statement.
• fields: Specifying which fields to be returned, if passing nil the entire is returned, no automatic inclusion of _id or other metadata fields.
• sorts: How to order the documents returned, formatted as ["desc(fieldName1)", "desc(fieldName2)"] or ["fieldNameA", "fieldNameB"] of which "asc" is used by default, passing nil to disable ordering.
• limit: Maximum number of results returned, passing nil to use default value(25).
• skip: Skip the first 'n' results, where 'n' is the number specified, passing nil for no-skip.
• index: Instruct a query to use a specific index, specified either as "<design_document>" or ["<design_document>", "<index_name>"], passing nil to use primary index(_all_docs) by default.

For example:

docsQuery, err := movieDB.Query(nil, `year == 1989 && (director == "Ademir Kenovic" || director == "Dezs Garas")`, nil, nil, nil, nil)

equals to:

docsRaw, err := movieDB.QueryJSON(`
{
  "selector": {
    "year": 1989,
    "$or": [
      { "director": "Ademir Kenovic" },
      { "director": "Dezs Garas" }
    ]
  }
}`)

Inner functions for selector syntax

• nor(condexprs...) matches if none of the conditions in condexprs match($nor). For example: nor(year == 1990, year == 1989, year == 1997) returns all documents whose year field not in 1989, 1990 and 1997.

• all(field, array) matches an array value if it contains all the elements of the argument array($all). For example: all(genre, []string{"Comedy", "Short"} returns all documents whose genre field contains "Comedy" and "Short".

• any(field, condexpr) matches an array field with at least one element meets the specified condition($elemMatch). For example: any(genre, genre == "Short" || genre == "Horror") returns all documents whose genre field contains "Short" or "Horror" or both.

• exists(field, boolean) checks whether the field exists or not, regardless of its value($exists). For example: exists(director, false) returns all documents who does not have a director field.

• typeof(field, type) checks the document field's type, valid types are "null", "boolean", "number", "string", "array", "object"($type). For example: typeof(genre, "array") returns all documents whose genre field is of array type.

• in(field, array) the field must exist in the array provided($in). For example: in(director, []string{"Mike Portnoy", "Vitali Kanevsky"}) returns all documents whose director field is "Mike Portnoy" or "Vitali Kanevsky".

• nin(field, array) the document field must not exist in the array provided($nin). For example: nin(year, []int{1990, 1992, 1998}) returns all documents whose year field is not in 1990, 1992 or 1998.

• size(field, int) matches the length of an array field in a document($size). For example: size(genre, 2) returns all documents whose genre field is of length 2.

• mod(field, divisor, remainder) matches documents where field % divisor == remainder($mod). For example: mod(year, 2, 1) returns all documents whose year field is an odd number.

• regex(field, regexstr) a regular expression pattern to match against the document field. For example: regex(title, "^A") returns all documents whose title is begin with an "A".

Inner functions for sort syntax

asc(field) sorts the field in ascending order, this is the default option while desc(field) sorts the field in descending order.

Requirements

• Golang 1.7.x and above

Installation

go get -u -v github.com/leesper/couchdb-golang

Authors and acknowledgment

• Philipp Winter
• Serkan Sipahi
• paduraru
• Andrei Pavel
• jcantonio

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change. Please make sure to update unit tests as appropriate.