Expresso.Rendering.Linq 0.12.1

Expresso

GitHub repository

Expresso is a .NET library for dynamic filtering and sorting. It parses a function-call query string into a validated expression tree, then renders the tree as parameterized SQL or as LINQ. It replaces hand-written WHERE and ORDER BY string concatenation, and piles of optional Where clauses, with one tested pipeline.

Query string → Expresso.Parsing → expression tree (Expresso.Core) ─┬→ SQL renderer (one per dialect) → SQL + parameters
                                                                   └→ LINQ renderer (Linq, EF Core, EF6) → predicate + sort keys

Target frameworks: netstandard2.0 and net6.0 for the core, parsing, SQL and LINQ packages (usable from .NET Framework 4.6.1+, .NET Standard 2.0 libraries and .NET 6+). The EF Core package targets net8.0, and the EF6 package targets net48. License: MIT.

Example

A client sends a filter and a sort:

gt(createdAt,"2021-01-01")
createdAt,desc,name,asc

With a field map that sends createdAt to p.created_at and the parameter prefix wparam, each SQL renderer produces the same condition in its own dialect:

The LINQ renderers produce a lambda instead, which EF Core or EF6 translates to SQL:

e => e.CreatedAt > p0

The grammar, literal rules and supported types are in Query syntax.

Packages

There is no metapackage: reference the packages you need. Database drivers and native clients are not included (DB2 needs IBM's clidriver on the host). See Packages.

Documentation

New to Expresso? Start with the overview, then Get started.

• Overview: what Expresso is for, use cases, and when not to use it
• Get started: install, register, describe fields, parse
  • Render to SQL for ADO.NET and Dapper
  • Render to LINQ and EF for EF Core, EF6 and in-memory collections
• Packages: each NuGet package and which ones you need
• Query policy: endpoint allow rules, deny rules, and resource limits
• Query syntax: filter and sort grammar, literals, supported types
• Pagination: paged and offset/number results, ordering, and totals
• Field providers: the field allow-list and query model
• SQL rendering: quoting and parameters per dialect
• LINQ rendering: profiles, EF Core, EF6 and provider limits
• Filter behavior and database differences: NULL handling, types and engine differences
• Error handling: exceptions from parsing and rendering
• Function reference: one page per function, grouped by category
• Sample app: a walkthrough of the sample Web API

Samples

• samples/Expresso.Sample.WebApi: .NET 10 ASP.NET Core host with Swagger (ADO.NET)
• samples/Expresso.Sample.WebApi.NetFx: .NET Framework 4.8 OWIN and Web API 2 host (ADO.NET)
• samples/Expresso.Sample.WebApi.EfCore: .NET 10 ASP.NET Core host (EF Core 8 + LINQ renderers)
• samples/Expresso.Sample.WebApi.NetFx.Ef6: .NET Framework 4.8 OWIN host (EF6 + LINQ renderers)

The ADO pair shares samples/Expresso.Sample.Shared. The EF pair is standalone (same routes and ExpressoSample:Engine, no Shared reference). Schema and seed: samples/database. See Sample app.

Build from source

dotnet test .\Expresso.slnx -c Release -f net6.0 --filter "Category!=Integration"
dotnet test .\Expresso.slnx -c Release -f net48 --filter "Category!=Integration"    # Windows; validates .NET Framework consumers
dotnet pack .\Expresso.slnx -c Release -o .\artifacts

Tests that need a running database engine skip unless EXPRESSO_IT=1. See test/Rendering/Expresso.Rendering.Integration.Test/README.md.