Diesel Tiberius

A SQL Server third-party backend for Diesel based on Tiberius.

Work in progress.

Contributing

To run the tests, create a local instance of SQL Server with Docker or Podman:

docker run -e "ACCEPT_EULA=Y" -e "MSSQL_SA_PASSWORD=AStrongPassword123!" \
   -p 1433:1433 --name local_mssql \
   -d \
   mcr.microsoft.com/mssql/server:2022-latest

You might have to connect to it and create a database.

docker exec -it local_mssql /opt/mssql-tools18/bin/sqlcmd -S localhost -C -U SA -P AStrongPassword123! -Q "CREATE DATABASE diesel_mssql_db"

The tests are currently in a separate crate in the workspace. To run them:

cd tests
cargo test

Make a copy of .env.sample in the tests crate and rename it to .env and edit the values.

Known issues and limitations

All tests as of this commit are passing except the ones marked with ignore and an explanation.

There are many issues left to be fixed.

• The test transaction_executes_fn_in_a_sql_transaction is ignored because it takes forever. The statements seem to be blocking in SQL Server. Trying the same queries in Azure Data Studio yields the same results.
• OUTPUT (returning clause) is not yet implemented.
• NULL values are bound with VARBINARY by default.
• Selecting with equality operators on column values will error. The syntax is not supported in SQL Server and has to be rewritten to something like

SELECT CASE WHEN a = b THEN CONVERT(BIT, 1) ELSE CONVERT(BIT, 0) END AS c FROM d;

• Using the offset or order DSL methods on boxed queries will fail. If you need syntax like in the test boxed_queries::boxed_queries_implement_offset_dsl, limit_offset::boxed_limit or limit_offset::boxed_offset this will probably require Diesel to add order clauses to limit-offset upstreams.