C# EF框架调用数据库的函数

1.在数据库中创建一个自定义函数：

REATE FUNCTION [dbo].[f_IsOriginsDisabled] ( @origins varchar(50), @needPPTV bit ) RETURNS bit AS BEGIN if @origins='' begin RETURN 1; end declare @disables varchar(50); set @disables=''; if @needPPTV=0 begin set @disables = @disables + ',6'; end select @disables = @disables + ',' + CAST(Id AS varchar(50)) + ',' from Video_Origin where IsDel=0 and IsEnabled=0 DECLARE @ix int, @pos int, @str varchar(1000); SET @pos = 1; SET @ix = 1; WHILE @ix > 0 BEGIN SET @ix = charindex(',', @origins, @pos) IF @ix > 0 SET @str = substring(@origins, @pos, @ix - @pos); ELSE SET @str = substring(@origins, @pos, len(@origins)); SET @str = ltrim(rtrim(@str)); if charindex(','+@str+',',@disables)<=0 return 0; SET @pos = @ix + 1; END RETURN 1; END GO

2.创建EF的数据库上下文：

引用 EntityFramework.Functions程序集

public class MediaDBContext : DbContext, IDisposable { public MediaDBContext() : base("MediaDBContext") { } protected override void OnModelCreating(DbModelBuilder modelBuilder) { base.OnModelCreating(modelBuilder); modelBuilder.Conventions.Add(new FunctionConvention<MediaDBContext>()); } /// <summary> /// 判断当前源是否全部失效 /// </summary> /// <param name="origins">视频源</param> /// <param name="needPPTV">是否需要PPTV源</param> /// <returns></returns> [Function(FunctionType.ComposableScalarValuedFunction, "f_IsOriginsDisabled", Schema = "dbo")] [return: Parameter(DbType = "bit")] public bool IsOriginsDisabled([Parameter(DbType = "varchar")]string origins, [Parameter(DbType = "bit")]bool needPPTV) { return Function.CallNotSupported<bool>(); } }

3.调用方式：

var query = context.Movies .Where(m => !context.IsOriginsDisabled(m.Origins, hasPPTV);

上面步骤已经使用EF调用数据库的函数了。

4.详细介绍EF怎样调用数据库中的存储过程与函数文档说明：

https://weblogs.asp.net/dixin/entityframework.functions　　

 

转载于:https://www.cnblogs.com/zoro-zero/p/5368131.html

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