Make sure you do using DataFrames using SQLite
in that order in a fresh Julia session to ensure the conversion methods get defined (when you load the SQLite package, it checks if DataFrames has already been loaded to define the conversion routines). -Jacob On Wed, May 25, 2016 at 10:43 PM, SHORE SHEN <[email protected]> wrote: > Hi Alex > > thanks so much for your reply, I tried out the method but it fails when > using DataFrame(Data.stream!(source, Data.Table)) commend. It reported no > such method error msg as follow: > > MethodError: `convert` has no method matching > convert(::Type{DataFrames.DataFrame}, > ::DataStreams.Data.Table{Array{NullableArrays.NullableArray{T,1},1}}) > This may have arisen from a call to the constructor > DataFrames.DataFrame(...), > since type constructors fall back to convert methods.WARNING: Error > showing method candidates, aborted > > in call at essentials.jl:56 > in include_string at C:\Users\shoren\.julia\v0.4\CodeTools\src\eval.jl:28 > in include_string at C:\Users\shoren\.julia\v0.4\CodeTools\src\eval.jl:32 > [inlined code] from C:\Users\shoren\.julia\v0.4\Atom\src\eval.jl:39 > in anonymous at C:\Users\shoren\.julia\v0.4\Atom\src\eval.jl:62 > in withpath at C:\Users\shoren\.julia\v0.4\Requires\src\require.jl:37 > in withpath at C:\Users\shoren\.julia\v0.4\Atom\src\eval.jl:53 > [inlined code] from C:\Users\shoren\.julia\v0.4\Atom\src\eval.jl:61 > in anonymous at task.jl:58 > > 在 2016年5月26日星期四 UTC+8上午12:30:52，Alex Mellnik写道： > >> >> Yes to both! >> >> For the first one, you want to use Data.stream! to get a Data.Table from >> the result set, and then convert it to a DataFrame. For the second you >> need to do the opposite. I generally work with DataFrames so I wrote two >> convenience functions for doing this, which should give you an idea of how >> to go about it: >> >> function queryToDF(db, query) >> source = SQLite.Source(db, query) >> return DataFrame(Data.stream!(source, Data.Table)) >> end >> >> function dfToDB(db, df, table) >> sink = SQLite.Sink(Data.Table(df), db, table) >> Data.stream!(Data.Table(df), sink) >> end >> >> Cheers -A >> >> On Wednesday, May 25, 2016 at 2:54:26 AM UTC-7, SHORE SHEN wrote: >>> >>> Hello >>> >>> Im trying out the sqlite package in julia, I got the following 2 >>> questions: >>> >>> 1, the query will result in a type of SQLite.ResultSet, if i can output >>> dataframe or dataarry type? >>> >>> 2, if i have a dataframe or dataarray type, would i be able to put it >>> into the database table? >>> >>> thanks a lot! >>> >>
