Database query performance LinqDB vs Sql query the database query - DataTable Entity types of data transfer

Use LinqDB Sqlite database query data, whether large or small amounts of data data, I feel particularly time-consuming, especially in the first query

A data table containing data of 27000

The first query:

Query 27000 data, time-consuming 1s
8 data query, but also took 750ms

Secondary query:

27000 data query, took 475ms
Queries a specified data and time-consuming 73ms

Let's try to optimize it, use Sql statement to query

Sql query the database

Sql connection string:

1     var dbRelativePath = "Dbs\\EnglishDict.db3";
2     var connectionString = "data source=" + System.Environment.CurrentDirectory + "\\" + dbRelativePath + ";version=3;";

Sql query returns a DataSet collection

 1    /// <summary>
 2     /// 获得数据列表
 3     /// </summary>
 4     public DataSet GetList(string strWhere, string tableName)
 5     {
 6         StringBuilder strSql = new StringBuilder();
 7         strSql.Append("select * ");
 8         strSql.Append($" FROM {tableName} ");
 9         if (strWhere.Trim() != "")
10         {
11             strSql.Append ( " WHERE " + strWhere);
 12 is          }
 13 is          return Query (strSql.ToString ());
 14      }
 15      ///  <Summary> 
16      /// execute a query, returns the DataSet
 . 17      ///  </ Summary > 
18 is      ///  <param name = "SqlString"> query </ param> 
. 19      ///  <Returns> the DataSet </ Returns> 
20 is      public the DataSet query ( String SqlString)
 21 is      {
 22 is          the using (SQLiteConnection connection = new SQLiteConnection(connectionString))
23         {
24             DataSet ds = new DataSet();
25             try
26             {
27                 connection.Open();
28                 SQLiteDataAdapter command = new SQLiteDataAdapter(sQLString, connection);
29                 command.Fill(ds, "ds");
30             }
31             catch (System.Data.SQLite.SQLiteException ex)
32             {
33                 throw new Exception(ex.Message);
34             }
35             return ds;
36         }
37     }

DataSet dataset data transfer list

1. Using reflection, the data is mapped to the class Entity

See database query - DataTable Entity types of data transfer

. 1      ///  <Summary> 
2      /// obtain data list
 . 3      ///  </ Summary> 
. 4      public List <CoursewareInfo> GetCoursewares ()
 . 5      {
 . 6          the DataSet the GetList DS = ( String .Empty, " Courseware " );
 . 7          / / by mapping, DataSet transfer entity classes 
. 8          var modelList = DataTableConverter <CoursewareInfo> .ToList (ds.Tables [ 0 ]);
 . 9          return modelList;
 10      }
 . 11      ///  <Summary> 
12 is      /// obtained data list
13     /// </summary>
14     public List<CoursewareInfo> GetCoursewares(string queryText)
15     {
16         var queryString = $"Name like '%{queryText}%'";
17         DataSet ds = GetList(queryString, "Courseware");
18         //通过映射，DataSet转实体类
19         var modelList = DataTableConverter<CoursewareInfo>.ToList(ds.Tables[0]);
20         return modelList;
21     }

We look at the performance of the query data or the same data table

The first query:

27000 data query, took 1612ms
Queries a specified data, but also took 196ms

Secondary query:

27000 data query, took 1484ms
Queries a specified data and time-consuming 59ms

This program time-consuming, it should be reflected hurt performance, give up

2. Direct Data Class field attribute assignment to

DataTable transfer data class:

 1         /// <summary>
 2         /// 将DataTable转换成Entity列表
 3         /// </summary>
 4         /// <param name="dt"></param>
 5         /// <returns></returns>
 6         public List<CoursewareInfo> ConvertDtToModelList(DataTable dt)
 7         {
 8             List<CoursewareInfo> list = new List<CoursewareInfo>();
 9             foreach (DataRow dr in dt.Rows)
10             {
11                 list.Add(DataRowToModel(dr));
12             }
13             return list;
14         }
15         /// <summary>
16         /// 得到一个对象实体
17         /// </summary>
18         public CoursewareInfo DataRowToModel(DataRow row)
19         {
20             CoursewareInfo model = new CoursewareInfo();
21             if (row != null)
22             {
23                 model.LocalId = row["LocalId"].ToString();
24                 model.RemoteId = row["RemoteId"].ToString();
25                 model.Name = row["Name"].ToString();
26             }
27             return model;
28         }

Gets a list:

. 1      ///  <Summary> 
2      /// obtain data list
 . 3      ///  </ Summary> 
. 4      public List <CoursewareInfo> GetCoursewares ()
 . 5      {
 . 6          the DataSet the GetList DS = ( String .Empty, " Courseware " );
 . 7          / / via field assignment, DataSet transfer entity classes 
. 8          var modelList = ConvertDtToModelList (ds.Tables [ 0 ]);
 . 9          return modelList;
 10      }
 . 11      ///  <Summary> 
12 is      /// obtain data list
 13     ///  </ Summary> 
14      public List <CoursewareInfo> GetCoursewares ( String the queryText)
 15      {
 16          var the queryString $ = " the Name like 'the queryText% {%}' " ;
 . 17          the DataSet DS = the GetList (the queryString, " Courseware " );
 18          // through field assignment, DataSet transfer entity classes 
. 19          var modelList = ConvertDtToModelList (ds.Tables [ 0 ]);
 20 is          return modelList;
 21 is      }

Look at the performance of the query data or the same data table

The first query:

27000 data query, took 660ms
Queries a specified data, but also took 191ms

Secondary query:

27000 data query, took 500ms
Queries a specified data and time-consuming 58ms

In this scenario, data query performance is significantly improved.

Summary: Relative LINDB, use Sql query program query data performance will be much better