使用EntityFrameworkCore

虽然Nebula默认使用ClownFish中提供的数据访问模块，但也支持使用其它的数据访问模块。

本文将介绍如何在Nebula中使用EntityFrameworkCore



添加NuGet包

例如：

<PackageReference Include="Microsoft.EntityFrameworkCore" Version="7.0.2" />
<PackageReference Include="Pomelo.EntityFrameworkCore.MySql" Version="7.0.0" />
<PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="7.0.0" />
<PackageReference Include="Npgsql.EntityFrameworkCore.PostgreSQL" Version="7.0.0" />



定义EF-DbContext继承类

示例代码如下

public class MyNorthwindEfDbContext : Microsoft.EntityFrameworkCore.DbContext
{
    public DbSet<Product> Product { get; set; }

  
    private readonly DbConfig _dbConfig;

    public MyNorthwindEfDbContext(DbConfig dbConfig)
    {
        _dbConfig = dbConfig;
    }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        string connectionString = _dbConfig.GetConnectionString(true);

        if( _dbConfig.DbType == DatabaseType.SQLSERVER )
            optionsBuilder.UseSqlServer(connectionString);

        else if( _dbConfig.DbType == DatabaseType.MySQL ) {

            ServerVersion version = ServerVersion.AutoDetect(connectionString);
            optionsBuilder.UseMySql(connectionString, version, null);
        }

        else if( _dbConfig.DbType == DatabaseType.PostgreSQL )
            optionsBuilder.UseNpgsql(connectionString);

        else if( _dbConfig.DbType == DatabaseType.DaMeng )
            optionsBuilder.UseDm(connectionString);

        else
            throw new NotSupportedException();
    }
}



在代码中使用

以下代码来自 Controller 中的示例

[Route("search/{index}/{size}.aspx")]
public PageListResult<Product> Search([FromBody] ProductSearchParam product, int index, int size)
{
    PageListResult<Product> result = new PageListResult<Product>();
    result.PagingInfo = new PagingInfo();
    result.PagingInfo.PageIndex = index;
    result.PagingInfo.PageSize = size;

    DbConfig dbConfig = DbConnManager.GetAppDbConfig("conn-name");

    using( MyNorthwindEfDbContext dbContext = new MyNorthwindEfDbContext(dbConfig) ) {

        var query = dbContext.Product.Select(x => x);

        if( product.CategoryID > 0 )
            query = query.Where(x => x.CategoryID == product.CategoryID);

        if( product.UnitPrice > 0 )
            query = query.Where(x => x.UnitPrice > product.UnitPrice);

        if( product.Unit.HasValue() )
            query = query.Where(x => x.Unit == product.Unit);

        if( product.ProductName.HasValue() )
            query = query.Where(x => EF.Functions.Like(x.ProductName, product.ProductName + "%"));

        query = query.OrderBy(x => x.ProductID);

        result.Data = query.ToList();
        return result;
    }
}

性能日志展示如下：

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