Npgsql使用入门(三)【批量导入数据】

Program.cs代码:

 class Program{static void Main(string[] args){var test = new PgBulkCopyHelper<SingleBuilding>("bld_amap_gzmain");foreach (string pName in test.PropNames){Console.WriteLine("name: {0},\t\ttype: {1}", pName, test.PropInfo[pName]);}//-----------------------------------------------------------------------------------------------//定义每次插入的最大数量限制int maxNum = 1; //100000;//初始化对应的数据表DataTable dataTable = test.InitDataTable();string connectionString = "Host=localhost;Username=king;Password=wu12345;Database=dellstore";List<List<SingleBuilding>> bldsList = new List<List<SingleBuilding>>();NpgsqlPolygon plg1 = new NpgsqlPolygon(10);plg1.Add(new NpgsqlPoint(0.0, 0.0));plg1.Add(new NpgsqlPoint(6.0, -1.0));plg1.Add(new NpgsqlPoint(5.0, 3.0));plg1.Add(new NpgsqlPoint(1.0, 2.0));NpgsqlPolygon plg2 = new NpgsqlPolygon(10);plg2.Add(new NpgsqlPoint(100.0, 10.0));plg2.Add(new NpgsqlPoint(40.0, 180.0));plg2.Add(new NpgsqlPoint(190.0, 60.0));plg2.Add(new NpgsqlPoint(10.0, 60.0));plg2.Add(new NpgsqlPoint(160.0, 180.0));List<SingleBuilding> sblist1 = new List<SingleBuilding>(){new SingleBuilding(){id=System.Guid.NewGuid(),tile_x=1,         tile_y=2,         bps_gc=plg1,bps_llc=plg2,cp_gc=new NpgsqlPoint(0,0),   cp_llc=new NpgsqlPoint(100,10),  name="测试文本1",bld_floor=111,     height=22           },new SingleBuilding(){id=System.Guid.NewGuid(),tile_x=1,         tile_y=2,         bps_gc=plg1,bps_llc=plg2,cp_gc=new NpgsqlPoint(0,0),   cp_llc=new NpgsqlPoint(100,10),  name="测试文本2",bld_floor=222,     height=444     }};bldsList.Add(sblist1);using (var conn = new NpgsqlConnection(connectionString)){conn.Open();foreach (List<SingleBuilding> blds in bldsList){if (blds != null && blds.Count > 0){//填充数据test.FillDataTable(blds, dataTable);}//判断 dataTable 里面的数据量是否已经超过规定最大行数 maxNumif (dataTable.Rows.Count>maxNum){//如果是，则将 dataTable 里面的数据插入到数据库中test.BulkInsert(conn, dataTable);//清空 dataTable 中的现有数据dataTable.Clear();}}}}}public class SingleBuilding{//创建数据表的SQL语句如下：/*CREATE TABLE bld_amap_gzmain (id uuid PRIMARY KEY NOT NULL,tile_x integer,             --x index of the map tile where the building is locatedtile_y integer,             --y index of the map tile where the building is locatedbps_gc polygon NOT NULL,    --the points of the bottom outline of the building, geodetic coordinatesbps_llc polygon NOT NULL,   --the points of the bottom outline of the building, Latitude and longitude coordinatescp_gc point NOT NULL,       --the center point of the building, geodetic coordinatescp_llc point NOT NULL,      --the center point of the building, Latitude and longitude coordinatesname text,bld_floor smallint,         --the number of floors of the buildingheight real                 --the height of building);*/public Guid id { get; set; }public int? tile_x { get; set; }public int? tile_y { get; set; }public NpgsqlPolygon bps_gc { get; set; }public NpgsqlPolygon bps_llc { get; set; }public NpgsqlPoint cp_gc { get; set; }public NpgsqlPoint cp_llc { get; set; }public string name { get; set; }public short? bld_floor { get; set; }public float? height { get; set; }}

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PgBulkCopyHelper.cs代码:

using Npgsql;
using System;
using System.Collections.Generic;
using System.Data;
using System.Globalization;
using System.Linq;
using System.Reflection;namespace PgBulkCopyHelper
{/// <summary>/// 用以快速将大批量数据插入到postgresql中/// </summary>/// <typeparam name="TEntity"></typeparam>public class PgBulkCopyHelper<TEntity>{/// <summary>/// TEntity的属性信息/// Dictionary(string "property_name", Type property_type)/// </summary>public Dictionary<string, Type> PropInfo { get; set; }/// <summary>/// TEntity的属性名称列表/// </summary>public List<string> PropNames { get; set; }/// <summary>/// 数据表全名：schema.tableName or tableName/// </summary>public string FullTableName { get; set; }/// <summary>/// 构造函数/// </summary>/// <param name="schema">数据表的schema，一般为public</param>/// <param name="tableName">数据表的名称</param>public PgBulkCopyHelper(string schema, string tableName){PropNames = new List<string>();PropInfo = new Dictionary<string, Type>();PropertyInfo[] typeArgs = GetPropertyFromTEntity();foreach (PropertyInfo tParam in typeArgs){PropNames.Add(tParam.Name);PropInfo[tParam.Name] = tParam.PropertyType;}if (!string.IsNullOrWhiteSpace(tableName)){if (string.IsNullOrWhiteSpace(schema)){FullTableName = tableName;}elseFullTableName = string.Format("{0}.{1}", schema, tableName);}}/// <summary>/// 构造函数/// </summary>/// <param name="tableName">数据表的名称</param>public PgBulkCopyHelper(string tableName):this(null, tableName){ }/// <summary>/// 获取TEntity的属性信息/// </summary>/// <returns>TEntity的属性信息的列表</returns>private PropertyInfo[] GetPropertyFromTEntity(){Type t = typeof(TEntity);PropertyInfo[] typeArgs = t.GetProperties();return typeArgs;}/// <summary>/// 根据TEntity的属性信息构造对应数据表/// </summary>/// <returns>只有字段信息的数据表</returns>public DataTable InitDataTable(){DataTable dataTable = new DataTable();foreach(PropertyInfo tParam in GetPropertyFromTEntity()){Type propType = tParam.PropertyType;//由于 DataSet 不支持 System.Nullable<> 类型，因此要先做判断if ((propType.IsGenericType) && (propType.GetGenericTypeDefinition() == typeof(Nullable<>)))propType = propType.GetGenericArguments()[0];dataTable.Columns.Add(tParam.Name, propType);}return dataTable;}/// <summary>/// 根据TEntity可枚举列表填充给定的数据表/// </summary>/// <param name="entities">TEntity类型的可枚举列表</param>/// <param name="dataTable">数据表</param>public void FillDataTable(IEnumerable<TEntity> entities, DataTable dataTable){if (entities != null && entities.Count() > 0){foreach (TEntity entity in entities){FillDataTable(entity, dataTable);}}}/// <summary>/// 在DataTable中插入单条数据/// </summary>/// <param name="entity">具体数据</param>/// <param name="dataTable">数据表</param>public void FillDataTable(TEntity entity, DataTable dataTable){var dataRow = dataTable.NewRow();int colNum = dataTable.Columns.Count;PropertyInfo[] typeArgs = GetPropertyFromTEntity();for (int i = 0; i < colNum; i++){dataRow[i] = typeArgs[i].GetValue(entity);}dataTable.Rows.Add(dataRow);}/// <summary>/// 通过PostgreSQL连接把dataTable中的数据整块填充到数据库对应的数据表中/// 注意，该函数不负责NpgsqlConnection的创建、打开以及关闭/// </summary>/// <param name="conn">PostgreSQL连接</param>/// <param name="dataTable">数据表</param>public void BulkInsert(NpgsqlConnection conn, DataTable dataTable){var commandFormat = string.Format(CultureInfo.InvariantCulture, "COPY {0} FROM STDIN BINARY", FullTableName);using (var writer = conn.BeginBinaryImport(commandFormat)){foreach (DataRow item in dataTable.Rows)writer.WriteRow(item.ItemArray);}}}
}

运行结果如图:

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