Finally we have a new version of Linq To DB almost done.

Bases on amount and severity of reports for this release we will decide later wether we need another RC before final release.

For any questions regarding v6 migration, please use this discussion

Main changes in this (RC1) release:

• [breaking] we reorganized Linq To DB namespaces into two categories: general use public APIs in LinqToDB.* and internal APIs (mostly intended for external provider development or advanced functionality) in LinqToDB.Internal.* namespaces. If you cannot find some types/methods - check their new location in source or ask here
• [breaking] async IEnumerable extensions were moved from LinqToDB namespace to LinqToDB.Async to simplify resolve of naming conflicts for users who use other libraries with same extensions
• [breaking] drop .NET 6 and EF.Core 6 support
• a lof of work were done to improve translation of predicates (especially complex) to SQL:
  • complex predicate expressions that could fail translate before to SQL for all or for specific databases now should work
  • a lot of new optimizations implemented to simplify predicates
  • fixed support for mappings with IsPredicate=true option, done using Sql.FunctionAttribute or Sql.ExtensionAttribute attributes
  • fixed a lot of issues in predicate generation, including fixes to nullability tracking for nested predicates
• multiple improvemens in JOINs generation:
  • automatically promote LEFT joins to INNER when query filters effectively already remove empty records
  • improve nullability tracking for LEFT joins
• [all databases] fix/add translations of string.PadLeft, string.Length and Guid.ToString() members
• add Sql.Parameter(x) and Sql.Constant(x) helpers to explicitly specify value translation type (as parameter or as literal) for specific value
• FromSqlScalar API now expects user to use value alias for column name. It will be generated automatically for databases, which support column aliases specification in subquery alias clause. For other databases it should be specified by user in SQL.
• added UseOptions API on data context to temporary change context settings
• added initial support for new SQL dialects: SQL Server 2025 and PostgreSQL 18
• [EF.Core] import enum mappings for PostgreSQL from EF.Core model
• [RemoteContext] released new remote context transports: HttpClient (server, client) and Signal/R (server, client)
• a lot of other bugfixes and improvements

For full list of changes check this page

Release notes

Nugets

New Contributors

• @denis-tsv made their first contribution in https://github.com/linq2db/linq2db/pull/4916
• @rameel made their first contribution in https://github.com/linq2db/linq2db/pull/4918
• @ffried made their first contribution in https://github.com/linq2db/linq2db/pull/4957
• @Akilaydin made their first contribution in https://github.com/linq2db/linq2db/pull/4970
• @GulpakMarina made their first contribution in https://github.com/linq2db/linq2db/pull/4868

Full Changelog: https://github.com/linq2db/linq2db/compare/v6.0.0-preview.4...v6.0.0-rc.1