Npgsql使用入門(三)【批量導入數據】

Program.cs代碼:

 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]);}//-----------------------------------------------------------------------------------------------//定義每次插入的最大數量限制int maxNum = 1; //100000;//初始化對應的數據表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="測試文本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="測試文本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){//填充數據test.FillDataTable(blds, dataTable);}//判斷 dataTable 里面的數據量是否已經超過規定最大行數 maxNumif (dataTable.Rows.Count>maxNum){//如果是，則將 dataTable 里面的數據插入到數據庫中test.BulkInsert(conn, dataTable);//清空 dataTable 中的現有數據dataTable.Clear();}}}}}public class SingleBuilding{//創建數據表的SQL語句如下：/*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代碼:

using Npgsql;
using System;
using System.Collections.Generic;
using System.Data;
using System.Globalization;
using System.Linq;
using System.Reflection;namespace PgBulkCopyHelper
{/// <summary>/// 用以快速將大批量數據插入到postgresql中/// </summary>/// <typeparam name="TEntity"></typeparam>public class PgBulkCopyHelper<TEntity>{/// <summary>/// TEntity的屬性信息/// Dictionary(string "property_name", Type property_type)/// </summary>public Dictionary<string, Type> PropInfo { get; set; }/// <summary>/// TEntity的屬性名稱列表/// </summary>public List<string> PropNames { get; set; }/// <summary>/// 數據表全名：schema.tableName or tableName/// </summary>public string FullTableName { get; set; }/// <summary>/// 構造函數/// </summary>/// <param name="schema">數據表的schema，一般為public</param>/// <param name="tableName">數據表的名稱</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>/// 構造函數/// </summary>/// <param name="tableName">數據表的名稱</param>public PgBulkCopyHelper(string tableName):this(null, tableName){ }/// <summary>/// 獲取TEntity的屬性信息/// </summary>/// <returns>TEntity的屬性信息的列表</returns>private PropertyInfo[] GetPropertyFromTEntity(){Type t = typeof(TEntity);PropertyInfo[] typeArgs = t.GetProperties();return typeArgs;}/// <summary>/// 根據TEntity的屬性信息構造對應數據表/// </summary>/// <returns>只有字段信息的數據表</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<> 類型，因此要先做判斷if ((propType.IsGenericType) && (propType.GetGenericTypeDefinition() == typeof(Nullable<>)))propType = propType.GetGenericArguments()[0];dataTable.Columns.Add(tParam.Name, propType);}return dataTable;}/// <summary>/// 根據TEntity可枚舉列表填充給定的數據表/// </summary>/// <param name="entities">TEntity類型的可枚舉列表</param>/// <param name="dataTable">數據表</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中插入單條數據/// </summary>/// <param name="entity">具體數據</param>/// <param name="dataTable">數據表</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>/// 通過PostgreSQL連接把dataTable中的數據整塊填充到數據庫對應的數據表中/// 注意，該函數不負責NpgsqlConnection的創建、打開以及關閉/// </summary>/// <param name="conn">PostgreSQL連接</param>/// <param name="dataTable">數據表</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);}}}
}

運行結果如圖:

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