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external/duckdb/tools/juliapkg/README.md

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+# Official DuckDB Julia Package
+
+DuckDB is a high-performance in-process analytical database system. It is designed to be fast, reliable and easy to use. For more information on the goals of DuckDB, please refer to [the Why DuckDB page on our website](https://duckdb.org/why_duckdb).
+
+The DuckDB Julia package provides a high-performance front-end for DuckDB. Much like SQLite, DuckDB runs in-process within the Julia client, and provides a DBInterface front-end.
+
+The package also supports multi-threaded execution. It uses Julia threads/tasks for this purpose. If you wish to run queries in parallel, you must launch Julia with multi-threading support (by e.g. setting the `JULIA_NUM_THREADS` environment variable).  
+
+
+## Installation
+
+```julia
+pkg> add DuckDB
+
+julia> using DuckDB
+```
+
+## Basics
+
+```julia
+# create a new in-memory database
+con = DBInterface.connect(DuckDB.DB, ":memory:")
+
+# create a table
+DBInterface.execute(con, "CREATE TABLE integers(i INTEGER)")
+
+# insert data using a prepared statement
+stmt = DBInterface.prepare(con, "INSERT INTO integers VALUES(?)")
+DBInterface.execute(stmt, [42])
+
+# query the database
+results = DBInterface.execute(con, "SELECT 42 a")
+print(results)
+```
+
+## Scanning DataFrames
+The DuckDB Julia package also provides support for querying Julia DataFrames. Note that the DataFrames are directly read by DuckDB - they are not inserted or copied into the database itself.
+
+If you wish to load data from a DataFrame into a DuckDB table you can run a `CREATE TABLE AS` or `INSERT INTO` query.
+
+```julia
+using DuckDB
+using DataFrames
+
+# create a new in-memory database
+con = DBInterface.connect(DuckDB.DB)
+
+# create a DataFrame
+df = DataFrame(a = [1, 2, 3], b = [42, 84, 42])
+
+# register it as a view in the database
+DuckDB.register_data_frame(con, df, "my_df")
+
+# run a SQL query over the DataFrame
+results = DBInterface.execute(con, "SELECT * FROM my_df")
+print(results)
+```
+
+## Original Julia Connector
+Credits to kimmolinna for the [original DuckDB Julia connector](https://github.com/kimmolinna/DuckDB.jl).
+
+## Contributing to the Julia Package
+
+### Formatting
+The format script must be run when changing anything. This can be done by running the following command from within the root directory of the project:
+
+```bash
+julia tools/juliapkg/scripts/format.jl
+```
+
+### Testing
+
+You can run the tests using the `test.sh` script:
+
+```
+./test.sh
+```
+
+Specific test files can be run by adding the name of the file as an argument:
+
+```
+./test.sh test_connection.jl
+```
+
+### Development
+
+Build using `DISABLE_SANITIZER=1 make debug`
+
+To run against a locally compiled version of duckdb, you'll need to set the `JULIA_DUCKDB_LIBRARY` environment variable, e.g.:
+
+```bash
+export JULIA_DUCKDB_LIBRARY="`pwd`/../../build/debug/src/libduckdb.dylib"
+```
+
+Note that Julia pre-compilation caching might get in the way of changes to this variable taking effect. You can clear these caches using the following command:
+
+```bash
+rm -rf ~/.julia/compiled
+```
+
+For development a few packages are required, these live in a Project.toml in the `test` directory, installed like so:
+
+```bash
+cd tools/juliapkg
+```
+
+```julia
+using Pkg
+Pkg.activate("./test")
+Pkg.instantiate()
+```
+
+#### Debugging using LLDB
+
+Julia's builtin version management system `juliaup` can get in the way of starting a process with lldb attached as it provides a shim for the `julia` binary.
+The actual `julia` binaries live in `~/.julia/juliaup/<version>/bin/julia`
+
+`lldb -- julia ...` will likely not work and you'll need to provide the absolute path of the julia binary, e.g:
+```bash
+lldb -- ~/.julia/juliaup/julia-1.10.0+0.aarch64.apple.darwin14/bin/julia ...
+```
+
+#### Testing
+
+To run the test suite in it's entirety:
+```bash
+julia -e "import Pkg; Pkg.activate(\".\"); include(\"test/runtests.jl\")"
+```
+
+To run a specific test listed in `test/runtests.jl`, you can provide the name, e.g:
+```bash
+julia -e "import Pkg; Pkg.activate(\".\"); include(\"test/runtests.jl\")" "test_basic_queries.jl"
+```
+
+Just as mentioned before, to attach lldb to this, you'll have to replace the `julia` part with the absolute path.
+
+### Automatic API generation
+
+A base Julia wrapper around the C-API is generated using the `update_api.sh` script (which internally calls the python script `scripts/generate_c_api_julia.py`). This script uses the definitions of DuckDB C-API to automatically generate the Julia wrapper that is complete and consistent with the C-API. To generate the wrapper, just run:
+
+```bash
+./update_api.sh
+```
+
+
+### Submitting a New Package
+The DuckDB Julia package depends on the [DuckDB_jll package](https://github.com/JuliaBinaryWrappers/DuckDB_jll.jl), which can be updated by sending a PR to [Yggdrassil](https://github.com/JuliaPackaging/Yggdrasil/pull/5049).
+
+After the `DuckDB_jll` package is updated, the DuckDB package can be updated by incrementing the version number (and dependency version numbers) in `Project.toml`, followed by [adding a comment containing the text `@JuliaRegistrator register subdir=tools/juliapkg`](https://github.com/duckdb/duckdb/commit/88b59799f41fce7cbe166e5c33d0d5f6d480278d#commitcomment-76533721) to the commit.