之前发表一个ABP框架+EF执行原生sql,后来自己想了想安装Dapper,用Dapper执行原生sql也可以,并且效率会比EF优一点。
一、首先安装Dapper
有多种方案安装,nuget包安装,或者执行命令
cs
dotnet add package Dapper
二、项目中使用
注意在当前文件引用Dapper
cs
using Dapper;
注入你要操作表的仓储
cs
private readonly IRepository<WorkOrder, Guid> _repository;
public WorkOrderExtensionService( IRepository<WorkOrder, Guid> repository){
_repository = repository;
}
写好自己要的sql业务,然后通过Dapper执行
cs
var parameters = new
{
TenantId = _currentTenant.Id,
SkipCount = input.SkipCount,
PageSize = input.MaxResultCount,
OrderId = orderId,
OrderNo = input.OrderNo,
};
var sql = @"
select w.SeriesNo,w.Seq, CASE WHEN r.SnCode is null THEN 0 ELSE 1 END `State` from JG_WorkOrderTasks w
left join (
select SnCode from JG_WorkOrderDistributionRecords
where WorkOrderNumber = @OrderNo and DispatchStatus = 1
group by SnCode
) r on w.SeriesNo = r.SnCode
where w.OrderId = @OrderId and IsDeleted = 0 and TenantId = @TenantId
order by `State`, Seq
limit @PageSize offset @SkipCount";
var countSql = @"
select count(0) from JG_WorkOrderTasks
where OrderId = @OrderId and IsDeleted = 0 and TenantId = @TenantId";
var dbContext = await _repository.GetDbContextAsync();
var connection = dbContext.Database.GetDbConnection();
if (connection.State != ConnectionState.Open)
await connection.OpenAsync();
var list = await connection.QueryAsync(sql, parameters);
var snCount = await connection.ExecuteScalarAsync<int>(countSql, parameters);
List<HitList> resData = list.Select(c => new HitList
{
SnCode = c.SeriesNo,
Seq = c.Seq,
HitState = c.State == 0 ? "未打标" : "已打标"
}).ToList();
三、解析一下上面代码
数据库上下文和连接:
cs
var dbContext = await _repository.GetDbContextAsync();
var connection = dbContext.Database.GetDbConnection();
if (connection.State != ConnectionState.Open)
await connection.OpenAsync();
- 通过
_repository获取数据库上下文并获取数据库连接。 - 检查连接状态,如果未打开,则异步打开连接。
执行查询:
cs
var list = await connection.QueryAsync(sql, parameters);
var snCount = await connection.ExecuteScalarAsync<int>(countSql, parameters);
- 使用 Dapper 的
QueryAsync方法执行主查询,返回一个结果列表。 - 使用
ExecuteScalarAsync<int>执行计数查询,返回总记录数。