DBaker.CosmosDbQueryConverter 1.0.0

DBaker.CosmosDbQueryConverter

Write native Cosmos DB SQL queries with automatic parameterization. No query builder abstractions - just Cosmos SQL with safe parameter handling.

Features

• Write real SQL - Use the full power of Cosmos DB SQL syntax, not a limited query builder API
• Automatic parameterization - Parameter injection protection without manual parameter management
• IntelliSense support - Lambda expressions give you autocomplete and prevent property name typos
• Smart array expansion - Arrays automatically expand into IN clause parameters
• JSON property mapping - Automatically resolves JsonProperty and JsonPropertyName attributes

Installation

dotnet add package DBaker.CosmosDbQueryConverter

Usage

Lambda Expressions (Recommended)

Write real Cosmos DB SQL with IntelliSense and automatic property mapping:

using DBaker.CosmosDbQueryConverter;

// Simple query with parameters and property names
var query = CosmosDbQuery.Convert((MyDocument c) =>
    $"SELECT * FROM {c} WHERE {c.Status} = {myStatus}");

// Nested properties
var query = CosmosDbQuery.Convert((MyDocument c) =>
    $"SELECT * FROM {c} WHERE {c.Address.City} = {myCity}");

// Array expansion for IN clauses
var query = CosmosDbQuery.Convert((MyDocument c) =>
    $"SELECT * FROM {c} WHERE {c.Category} IN {myCategories}");

// Multi-line queries with JOINs
var query = CosmosDbQuery.Convert((MyDocument doc, SubDocument sub) =>
    $"""
    SELECT *
    FROM {doc}
    JOIN {sub} IN {doc.SubDoc}
    WHERE {doc.Id} = {myId}
      AND {sub.Status} = {myStatus}
    """)

Properties are automatically mapped using JsonProperty (Newtonsoft.Json) or JsonPropertyName (System.Text.Json) attributes. If neither exist we fall back to the camel cased property name.

Interpolated Strings

Write native Cosmos SQL with interpolated values - all parameters are automatically handled:

var query = CosmosDbQuery.Convert(
    $"SELECT * FROM c WHERE c.id = {myId} AND c.status = {myStatus}");

// Arrays work here too
var query = CosmosDbQuery.Convert(
    $"SELECT * FROM c WHERE c.tag IN {myTags}")

Placeholder-based Queries

For dynamic query building with parameter arrays:

var query = CosmosDbQuery.Convert(
    "SELECT * FROM c WHERE c.category IN {0} AND c.price >= {1}",
    myCategories,
    minPrice)

How It Works

You write native Cosmos DB SQL queries. The library handles all the parameterization work automatically - converting values to named parameters (@p0, @p1, etc.) and expanding arrays into multiple parameters for IN clauses.

Before:

$"SELECT * FROM {c} WHERE {c.Status} IN {myStatuses}"

After:

SELECT * FROM c WHERE c.status IN (@p0, @p1, @p2)

Executing Queries

The Convert methods return a standard QueryDefinition that you pass directly to the Cosmos DB SDK:

var query = CosmosDbQuery.Convert((MyDocument c) =>
    $"SELECT * FROM {c} WHERE {c.Status} = {myStatus}");

var queryIterator = container.GetItemQueryIterator<MyDocument>(query);

Custom Field Name Resolution

Disable Camel Casing

By default, property names are converted to camel case. To use property names as-is:

var query = CosmosDbQuery.Convert(
    (MyDocument c) => $"SELECT * FROM {c} WHERE {c.Status} = {myStatus}",
    new DefaultFieldNameResolver(useCamelCase: false));

Custom Resolver

Create your own resolver by implementing IFieldNameResolver or inheriting from DefaultFieldNameResolver:

public class MyFieldNameResolver : DefaultFieldNameResolver
{
    protected override string GetJsonPropertyName(MemberInfo member)
    {
        // Your custom logic here
        return member.Name.ToLowerInvariant();
    }
}

var query = CosmosDbQuery.Convert(
    (MyDocument c) => $"SELECT * FROM {c} WHERE {c.Status} = {myStatus}",
    new MyFieldNameResolver());