# SQLite.jl and LibPQ.jl packages don't work when wrapped in a package
**URL:** https://discourse.julialang.org/t/sqlite-jl-and-libpq-jl-packages-dont-work-when-wrapped-in-a-package/103297
**Category:** General Usage
**Created:** [August 28, 2023, 3:05pm UTC](https://discourse.julialang.org/t/sqlite-jl-and-libpq-jl-packages-dont-work-when-wrapped-in-a-package/103297 "2023-08-28T15:05:02Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@andrey2185](https://discourse.julialang.org/u/andrey2185)
#### Post date: [August 28, 2023, 3:05pm UTC](https://discourse.julialang.org/t/sqlite-jl-and-libpq-jl-packages-dont-work-when-wrapped-in-a-package/103297/1 "2023-08-28T15:05:02Z")
Hello!
I found that the SQLite.jl and LibPQ.jl packages don’t work when wrapped in a package (not a module but a package with manifest and project.toml).
has anyone experienced this?
```julia
module N
import LibPQ
import Tables
const CONNECTION_STRING = "dbname=postgres user=postgres password=postgres"
const CONNECTION = LibPQ.Connection(CONNECTION_STRING)
function select_global_vars()
res = LibPQ.execute(CONNECTION, "select * from mytable")
return Tables.columntable(res)
end
end # module N
```
```julia
module M
import SQLite
import DBInterface
import Tables
const conn = SQLite.DB("./mybase.sqlite")
function select_global_vars()
return DBInterface.execute(conn, "select * from mytable") |> Tables.columntable
end
end # module M
```
```julia
_ _ _(_)_ | Documentation: https://docs.julialang.org
(_) | (_) (_) |
_ _ _| |_ __ _ | Type "?" for help, "]?" for Pkg help.
| | | | | | |/ _ | |
| | |_| | | | (_| | | Version 1.9.2 (2023-07-05)
_/ |\ __'_|_|_|\__'_| | Official https://julialang.org/ release
|__/ |
(@v1.9) pkg> activate .
Activating project at `C:\N`
(N) pkg> instantiate
┌ Warning: The active manifest file has dependencies that were resolved with a different julia version (1.8.5). Unexpected behavior may occur.
└ @ C:\N\Manifest.toml:0
Precompiling project...
1 dependency successfully precompiled in 3 seconds. 40 already precompiled.
(N) pkg> precompile
julia> using N
julia> N.select_global_vars()
[error | LibPQ]: UnknownError:
ERROR: UnknownError:
Stacktrace:
[1] error(logger::Memento.Logger, exc::LibPQ.Errors.PQResultError{LibPQ.Errors.CUN, LibPQ.Errors.EUNOWN})
@ Memento C:\Users\admin\.julia\packages\Memento\xnHxE\src\loggers.jl:463
[2] handle_result(jl_result::LibPQ.Result{false}; throw_error::Bool)
@ LibPQ C:\Users\admin\.julia\packages\LibPQ\CRtC5\src\results.jl:238
[3] handle_result
@ C:\Users\admin\.julia\packages\LibPQ\CRtC5\src\results.jl:230 [inlined]
[4] _multi_execute(jl_conn::LibPQ.Connection, query::String; throw_error::Bool, kwargs::Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
@ LibPQ C:\Users\admin\.julia\packages\LibPQ\CRtC5\src\results.jl:305
[5] _multi_execute
@ C:\Users\admin\.julia\packages\LibPQ\CRtC5\src\results.jl:298 [inlined]
[6] #execute#51
@ C:\Users\admin\.julia\packages\LibPQ\CRtC5\src\results.jl:294 [inlined]
[7] execute
@ C:\Users\admin\.julia\packages\LibPQ\CRtC5\src\results.jl:290 [inlined]
[8] select_global_vars()
@ N C:\N\src\N.jl:10
[9] top-level scope
@ REPL[5]:1
julia>
```
```julia
_ _ _(_)_ | Documentation: https://docs.julialang.org
(_) | (_) (_) |
_ _ _| |_ __ _ | Type "?" for help, "]?" for Pkg help.
| | | | | | |/ _ | |
| | |_| | | | (_| | | Version 1.9.2 (2023-07-05)
_/ |\ __'_|_|_|\__'_| | Official https://julialang.org/ release
|__/ |
(@v1.9) pkg> activate .
Activating project at `C:\M`
(M) pkg> instantiate
(M) pkg> precompile
Precompiling project...
1 dependency successfully precompiled in 1 seconds. 17 already precompiled.
julia> using M
julia> M.select_global_vars()
ERROR: SQLite.SQLiteException("out of memory")
Stacktrace:
[1] sqliteerror(args::SQLite.DB)
@ SQLite C:\Users\admin\.julia\packages\SQLite\aeqsS\src\SQLite.jl:34
[2] macro expansion
@ C:\Users\admin\.julia\packages\SQLite\aeqsS\src\base.jl:10 [inlined]
[3] prepare_stmt_wrapper
@ C:\Users\admin\.julia\packages\SQLite\aeqsS\src\SQLite.jl:109 [inlined]
[4] SQLite.Stmt(db::SQLite.DB, sql::String; register::Bool)
@ SQLite C:\Users\admin\.julia\packages\SQLite\aeqsS\src\SQLite.jl:146
[5] Stmt
@ C:\Users\admin\.julia\packages\SQLite\aeqsS\src\SQLite.jl:145 [inlined]
[6] prepare
@ C:\Users\admin\.julia\packages\SQLite\aeqsS\src\SQLite.jl:180 [inlined]
[7] execute
@ C:\Users\admin\.julia\packages\DBInterface\1Gmxx\src\DBInterface.jl:130 [inlined]
[8] #execute#2
@ C:\Users\admin\.julia\packages\DBInterface\1Gmxx\src\DBInterface.jl:152 [inlined]
[9] execute
@ C:\Users\admin\.julia\packages\DBInterface\1Gmxx\src\DBInterface.jl:152 [inlined]
[10] select_global_vars()
@ M C:\M\src\M.jl:10
[11] top-level scope
@ REPL[5]:1
julia>
```
---
### Author:  [@quinnj](https://discourse.julialang.org/u/quinnj)
#### Post date: [August 28, 2023, 4:05pm UTC](https://discourse.julialang.org/t/sqlite-jl-and-libpq-jl-packages-dont-work-when-wrapped-in-a-package/103297/2 "2023-08-28T16:05:35Z")
This is because both these libraries wrap C libraries to provide the core functionality. Specifically, the `Connection` objects contain pointer “handles” to the C-library side of those objects and those aren’t valid to precompile in Julia modules. Instead, you’ll want to use the ` __init__ ` pattern to initialize these variables at runtime, something like:
```julia
module Foo
using SQLite
const CONN = Ref{SQLite.DB}()
function __init__ ()
CONN[] = SQLite.DB(":memory:")
end
end
```
You can then pass `CONN[]` to various `execute` calls and it should work.
---
### Author:  [@andrey2185](https://discourse.julialang.org/u/andrey2185)
#### Post date: [August 28, 2023, 4:14pm UTC](https://discourse.julialang.org/t/sqlite-jl-and-libpq-jl-packages-dont-work-when-wrapped-in-a-package/103297/3 "2023-08-28T16:14:11Z")
thank you