README
¶
Mongo Data Source
Provides SQL Access to Mongo via the DataUX Mysql Proxy Service.
mysql -h 127.0.0.1 -P4000
-- Create a new schema = "dbx1" with one source being
-- a mongo database called "mgo_datauxtest"
CREATE source mgo_datauxtest WITH {
"type":"mongo",
"schema":"dbx1",
"hosts": ["localhost:28017"]
};
-- Syntax: CREATE source DB_NAME WITH json_properties
-- DB_NAME = existing database in mongo, in this example "mgo_datauxtest"
-- WITH Properties:
-- "schema": Name of schema to attach this source to
-- "type": Source type, most be datasource registered in registry (mongo, bigtable, etc)
-- "hosts": Array of hosts:port
use dbx1;
show tables;
describe article;
select * from article;
SQL -> Mongo
| Mongo | SQL Query |
|---|---|
show collections |
show tables; |
| na, -- runtime inspection | describe mytable; |
db.accounts.find({},{created:{"$gte":"1/1/2016"}}).count(); |
select count(*) from accounts WHERE created > "1/1/2016"; |
db.article.find({"year":{"$in": [2013,2014,2015] }},{}} |
select * from article WHERE year IN (2015,2014,2013); |
db.article.find({"created":{"$gte": new Date('Aug 01, 2011'), "$lte": new Date('Aug 03, 2013') },{title:1,count:1,author:1}} |
`SELECT title, count, author FROM article WHERE created BETWEEN todate("2011-08-01") AND todate("2013-08-03") |
db.article.find({"title":{"Pattern":"^list","Options":"i"}},{title:1,count:1}) |
SELECT title, count AS ct FROM article WHERE title like \"list%\" |
| na, not avail in mongo (polyfill in dataux) | SELECT avg(CHAR_LENGTH(CAST(title, \"AS\", \"CHAR\"))) AS title_avg FROM article; |
| need to document ... | select min(year), max(year), avg(year), sum(year) from table WHERE exists(a); |
Documentation
¶
Index ¶
Constants ¶
View Source
const (
// SourceType for this mongo source.
SourceType = "mongo"
)
Variables ¶
View Source
var (
// DefaultLimit is default page size
DefaultLimit = 20
)
Functions ¶
Types ¶
type ResultReader ¶
type ResultReader struct {
*exec.TaskBase
Docs []u.JsonHelper
Vals [][]driver.Value
Total int
Aggs u.JsonHelper
ScrollId string
// contains filtered or unexported fields
}
ResultReader Mongo implements result paging, reading - driver.Rows
func NewResultReader ¶
func NewResultReader(req *SqlToMgo, q *mgo.Query, limit int) *ResultReader
func (*ResultReader) Close ¶
func (m *ResultReader) Close() error
func (*ResultReader) Run ¶
func (m *ResultReader) Run() error
type ResultReaderNext ¶
type ResultReaderNext struct {
*ResultReader
}
ResultReaderNext a wrapper, allowing us to implement sql/driver Next() interface which is different than qlbridge/datasource Next()
type Source ¶
type Source struct {
// contains filtered or unexported fields
}
Source Mongo Data Source implements qlbridge DataSource interfaces to mongo server - singleton shared across all sessions/connections - creates connections by mgo.Session.Clone()
type SqlToMgo ¶
SqlToMgo Rewrite a Sql AST statement to a Mongo request
- Walk the AST and see what can be pushed down and what can't
- try to poly-fill the missing pieces
- stateful single use request
func NewSqlToMgo ¶
NewSqlToMgo create sql to mongo converter
func (*SqlToMgo) WalkExecSource ¶
Source Files
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