SqlDapper

This is a simple library to generate SQL based on POCO (or better PORO 🎉). This is the C# version of my F# library FSharpDapper.

It maps collections, records and anonymous types to SQL so this can be used with Dapper.

This library is reflection based to generate SQL - but queries are cached then making it quite efficient after warmup.

Implementation is provided for:

Generic SQL (Select, Insert, Update, Delete, DapperConnection<T>)
Specialized dialect MSSQL (Upsert)

📦 NuGet packages

Package	Status	Description
SqlDapper		Core package
SqlDapper.SqlServer		SqlServer provider

📚 Api

Namespace

First you have to use SqlDapper namespace before proceeding:

using SqlDapper;

Plain Old Record Object

In order to read/write data, you will need to define a record first (or a class with properties):

[Table("StatusEx")]
public record DbStatusEx([property: Key] string Name,
                         int Status,
                         string? Comment);

Available attributes are:

Table(name): force table name at class level. Default value is record/class name
Key: specify a property as a key (or part of key composite if multiple declarations)

Create connection

You have first to import an ADO.Net provider (SQLServer, SQlite...). A connection can then be created (for exemple for SQlite):

var conn = new DapperConnection<SQLiteConnection>("Data Source=sqldapper.db");
var status = conn.Select<DbStatusEx>(new { Name = "toto" });

Raw connection methods

Following operations are available (methods on IDapperConnection). Those operations are same as Dapper and basically allow unit testing the library:

Operation	Description
`Execute`	Run provided sql query using the parameter and returns the result from the query (an int)
`QueryScalar<T>`	Run provided sql query using the parameter and returns the single result of `T`
`Query<T>`	Run provided sql query using the parameter and returns a list of result of `T`
`TransactionScope`	Create a transaction scope - transaction must be disposed

Generic SQL builder methods

Following operations are available as extension methods on IDapperConnection:

Operation	Description
`Select<Table>`	Run select query using the conditions and returns a list of result of `Table`
`SelectAll<Table>`	Select all results from table `Table`
`Insert<Table>`	Insert values into table `Table`
`Update<Table>`	Update table Table` with values
`Delete<Table>`	Delete table `Table` using the conditions

Insert, Update, Delete support either a single value or a list. A value is either a record or an anonymous record.

SqlServer builder methods

Following operations are available as extension methods on IDapperConnection:

Operation	Description
`Upsert<Table>`	Upsert values into table `Table`

Upsert support either a single value or a list. A value is either a record or an anonymous record.

Examples

Upsert

using SqlDapper;

[Table("Status")]
public record DbStatus([property: Key] string Name, int Status);

var prm = new { Name = "tagada", Status = 42 };
using var tx = conn.TransactionScope();
conn.Upsert<DbStatus>(prm);
tx.Complete();

This generates following SQL:

MERGE INTO [Status] as TARGET 
USING (VALUES(@Name,@Status)) AS SOURCE ([Name],[Status]) ON SOURCE.[Name]=TARGET.[Name]
WHEN MATCHED THEN UPDATE SET [Status]=SOURCE.[Status] 
WHEN NOT MATCHED THEN INSERT ([Name],[Status]) VALUES (SOURCE.[Name],SOURCE.[Status]);

pchalamet / SqlDapper