ElasticsearchCRUD使用(四)【使用EF从SQLServer到Elasticsearch的数据传输】

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AdventureWorks2012用作数据库，可以在这里下载。您需要在代码工作之前安装数据库。

应用程序

创建一个新的控制台应用程序，并从NuGet下载ElasticsearchCRUD和Entity Framework。
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从AdventureWorks数据库创建代码第一个数据库。

向项目添加一个新项，选择ADO.NET实体数据模型：
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现在从数据库选项首先选择代码。数据库已经存在。

从Person架构添加所有表。 Address表和Person表将用作文档根。

创建的Address类需要更改。必须删除DbGeography SpatialLocation，因为这不是支持的类型。在ElasticsearchCRUD V1.0.8或更高版本中，可以使用JsonIgnore属性忽略这一点。

namespace DataTransferSQLToEl.SQLDomainModel{    using System;    using System.Collections.Generic;    using System.ComponentModel.DataAnnotations;    using System.ComponentModel.DataAnnotations.Schema;    using System.Data.Entity.Spatial;    [Table("Person.Address")]    public partial class Address    {        public int AddressID { get; set; }        [Required]        [StringLength(60)]        public string AddressLine1 { get; set; }        [StringLength(60)]        public string AddressLine2 { get; set; }        [Required]        [StringLength(30)]        public string City { get; set; }        public int StateProvinceID { get; set; }        [Required]        [StringLength(15)]        public string PostalCode { get; set; }        // This type is not supported yet...        //public DbGeography SpatialLocation { get; set; }        public Guid rowguid { get; set; }        public DateTime ModifiedDate { get; set; }        public virtual StateProvince StateProvince { get; set; }    }}

选择实体并将文档添加到Elasticsearch。 Address 传输实现如下：

public void SaveToElasticsearchAddress(){    IElasticsearchMappingResolver elasticsearchMappingResolver = new ElasticsearchMappingResolver();    using (var elasticsearchContext = new ElasticsearchContext("http://localhost:9200/", elasticsearchMappingResolver))    {        //elasticsearchContext.TraceProvider = new ConsoleTraceProvider();        using (var modelPerson = new ModelPerson())        {            int pointer = 0;            const int interval = 100;            int length = modelPerson.CountryRegion.Count();            while (pointer < length)            {                stopwatch.Start();                var collection = modelPerson.Address.OrderBy(t => t.AddressID).Skip(pointer).Take(interval).ToList<Address>();                stopwatch.Stop();                Console.WriteLine("Time taken for select {0} AddressID: {1}", interval, stopwatch.Elapsed);                stopwatch.Reset();                foreach (var item in collection)                {                    elasticsearchContext.AddUpdateDocument(item, item.AddressID);                    string t = "yes";                }                stopwatch.Start();                elasticsearchContext.SaveChanges();                stopwatch.Stop();                Console.WriteLine("Time taken to insert {0} AddressID documents: {1}", interval, stopwatch.Elapsed);                stopwatch.Reset();                pointer = pointer + interval;                Console.WriteLine("Transferred: {0} items", pointer);            }        }    }}

一次选择了一百个实体，并将其添加到ElasticsearchCRUD上下文中。这只是将对象添加到内存集合中。调用SaveChanges方法时，将每个实体序列化为JSON对象。当所有项目都被序列化时，HttpClient实例将HTTP批量POST请求中的所有对象发送到Elasticsearch。直到所有项都被传输为止。 ElasticsearchCRUD将所有子元素序列化为1-N。对已经转换的父对象的任何引用都将被忽略并保存为空属性。

创建的Elasticsearch 映射如下（对于Person和Address文档）：

{    "addresss": {        "mappings": {            "address": {                "properties": {                    "addressid": {                        "type": "long"                    },                    "addressline1": {                        "type": "string"                    },                    "addressline2": {                        "type": "string"                    },                    "city": {                        "type": "string"                    },                    "modifieddate": {                        "type": "date",                        "format": "dateOptionalTime"                    },                    "postalcode": {                        "type": "string"                    },                    "rowguid": {                        "type": "string"                    },                    "stateprovince": {                        "properties": {                            "countryregion": {                                "properties": {                                    "countryregioncode": {                                        "type": "string"                                    },                                    "modifieddate": {                                        "type": "date",                                        "format": "dateOptionalTime"                                    },                                    "name": {                                        "type": "string"                                    }                                }                            },                            "countryregioncode": {                                "type": "string"                            },                            "isonlystateprovinceflag": {                                "type": "boolean"                            },                            "modifieddate": {                                "type": "date",                                "format": "dateOptionalTime"                            },                            "name": {                                "type": "string"                            },                            "rowguid": {                                "type": "string"                            },                            "stateprovincecode": {                                "type": "string"                            },                            "stateprovinceid": {                                "type": "long"                            },                            "territoryid": {                                "type": "long"                            }                        }                    },                    "stateprovinceid": {                        "type": "long"                    }                }            }        }    },    "persons": {        "mappings": {            "person": {                "properties": {                    "additionalcontactinfo": {                        "type": "string"                    },                    "businessentityid": {                        "type": "long"                    },                    "demographics": {                        "type": "string"                    },                    "emailaddress": {                        "properties": {                            "businessentityid": {                                "type": "long"                            },                            "emailaddress1": {                                "type": "string"                            },                            "emailaddressid": {                                "type": "long"                            },                            "modifieddate": {                                "type": "date",                                "format": "dateOptionalTime"                            },                            "rowguid": {                                "type": "string"                            }                        }                    },                    "emailpromotion": {                        "type": "long"                    },                    "firstname": {                        "type": "string"                    },                    "lastname": {                        "type": "string"                    },                    "middlename": {                        "type": "string"                    },                    "modifieddate": {                        "type": "date",                        "format": "dateOptionalTime"                    },                    "namestyle": {                        "type": "boolean"                    },                    "personphone": {                        "properties": {                            "businessentityid": {                                "type": "long"                            },                            "modifieddate": {                                "type": "date",                                "format": "dateOptionalTime"                            },                            "phonenumber": {                                "type": "string"                            },                            "phonenumbertype": {                                "properties": {                                    "modifieddate": {                                        "type": "date",                                        "format": "dateOptionalTime"                                    },                                    "name": {                                        "type": "string"                                    },                                    "phonenumbertypeid": {                                        "type": "long"                                    }                                }                            },                            "phonenumbertypeid": {                                "type": "long"                            }                        }                    },                    "persontype": {                        "type": "string"                    },                    "rowguid": {                        "type": "string"                    },                    "suffix": {                        "type": "string"                    },                    "title": {                        "type": "string"                    }                }            }        }    }}

可以使用ElasticsearchCRUD如下读取保存的对象。

ublic Address GetAddressFromElasticsearch(int id){    Address address;    IElasticsearchMappingResolver elasticsearchMappingResolver = new ElasticsearchMappingResolver();    using (var elasticsearchContext = new ElasticsearchContext("http://localhost:9200/", elasticsearchMappingResolver))    {        address = elasticsearchContext.GetDocument<Address>(id);    }    return address;}

然后可以在控制台应用程序中使用。完成后，具有嵌套子对象的所有对象将作为文档保存在Elasticsearch中。

using System;namespace DataTransferSQLToEl{    class Program    {        static void Main(string[] args)        {            var repo = new Repo();            repo.SaveToElasticsearchPerson();            repo.SaveToElasticsearchAddress();            var personX = repo.GetPersonFromElasticsearch(345);            var addressX = repo.GetAddressFromElasticsearch(22);            Console.WriteLine(addressX);            Console.WriteLine(personX);        }    }}

如果您只希望保存父实体，并且不包含子实体（Elasticsearch中的NESTED对象），则可以在ElasticsearchCRUD上下文构造函数中设置此选项：

bool saveChildEntitiesAsNestedObjects = false;using (var elasticSearchContext =               new ElasticsearchContext(                 "http://localhost:9200/",                   elasticsearchMappingResolver,                   saveChildEntitiesAsNestedObjects               )      ){  // Do you coding here...}

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