Question

我想制作基本统计数据来获取表格或实体的数据计数，我想问我是否可以在实体框架中的一个查询中执行此操作？我可以在SQL查询中通过在存储过程中创建多于select语句来实现这一点

Answer 1

这是我的方法，最后你仍然应该构建SQL Select语句，但仍然。

首先，您应该添加名称空间：

using System.Data.Entity.Core.Metadata.Edm;
using System.Data.Entity.Infrastructure;
using System.Data.Entity.Core.Objects;

然后您可以使用此代码获取所有带行数的表。

YourDBEntities ent = new YourDBEntities();
ObjectContext context = ((IObjectContextAdapter)ent).ObjectContext;
MetadataWorkspace metadataWorkspace = context.MetadataWorkspace;
EntityContainer container = metadataWorkspace
    .GetItems<EntityContainer>(DataSpace.CSpace).First();
ReadOnlyMetadataCollection<EntitySetBase> entitySetBase = container.BaseEntitySets;

//Get Table Names
var tableNames = entitySetBase
    .Where(x => x.BuiltInTypeKind == BuiltInTypeKind.EntitySet) //Get Tables Only
    .Select(x => x.Name);

//Get data
foreach (var tableName in tableNames)
{
    //Counstruct query for each table
    var selectSQL = String.Format(@"SELECT '{1}', COUNT(1) AS Count  
                                    FROM {0}", tableName, tableName);
    ObjectQuery<DbDataRecord> query = context.CreateQuery<DbDataRecord>(selectSQL);
    ObjectResult<DbDataRecord> results = query.Execute(MergeOption.AppendOnly);
    DbDataRecord res =  results.First();
    //Write to console
    Console.WriteLine("Table '{0}' contains {1} of rows", res[0], res[1]);
}

在Entity Framework中选择多个非相关实体

1 个答案: