SQL INSERT INTO statement
INSERT INTO statement is used to insert new records into the table.
SQL INSERT INTO Syntax
INSERT INTO statement can have two forms of writing.
① The first form without specifying the column name you want to insert the data, just to provide value to be inserted:
INSERT INTO table_name
VALUES (value1,value2,value3,...);
② The second form need to specify the column names and values to be inserted:
INSERT INTO table_name (column1,column2,column3,...)
VALUES (value1,value2,value3,...);
BULK INSERT statement
BULK INSERT for mass data insertion
BULK INSERT Syntax
] FIRSTROW = first_row] - Specifies the number of the first line to be loaded. The default is the first row of the specified data file [[,] FIRE_TRIGGERS] - whether the start trigger
[[,] The FORMATFILE = 'format_file_path']
[[,] the KEEPIDENTITY] - import the identification value of the specified data file for identifying column
[[,] KEEPNULLS] - Specifies the column should remain empty during a bulk import operation null value, without any default values for the inserted column
[[,] = KILOBYTES_PER_BATCH KILOBYTES_PER_BATCH]
[[,] = LASTROW LAST_ROW] - last line number to be loaded
[[,] MAXERRORS = max_errors] - Maximum number specifies the syntax error occurs in the data, this number will more than cancel the bulk import operation.
[[,] ORDER ({column [ASC | DESC]} [, ... n])] - data designating data file will be sorted
[[,] = ROWS_PER_BATCH ROWS_PER_BATCH]
[[,] = ROWTERMINATOR 'row_terminator' ] - separator line identification symbol
[[,] TABLOCK] - Specifies the duration of the import operation acquired a table level lock is a mass
[[,] ERRORFILE = 'file_name '] - Specifies and can not collect malformed converted to OLE DB rowset file line.
)]
A simple example
To compare the difference between ordinary and BULK INSERT inserted one by one, we have a simple example, to see the effect of the actual operation.
Step 1: Create two different database table, points table for the Student and Student1, table structures are identical, only the ID, NAME, AGE three simple fields.
Step Two: Create a console program, through a simple cycle, data is written to generate 500,000 txt document, the key code is as follows:
/// <summary>
/// 生成测试数据
/// </summary>
private static void GenerateTestData()
{
string fileName = "sql";
int i = 1;
while (i <= 500000)
{
string strInsert = string.Format("{0},'test{0}',{0}|", i);
File.AppendText(strInsert, fileName);
i++;
}
}
The third step: a package two methods were used to perform bulk insert and insert general, specific code as follows:
/// <Summary>
/// bulk insert test
/// </ Summary>
Private static void BulkInsertTest ()
{
String strFilePath @ = "D: \ Learning \ the ASP.NET \ QYH.BlukInsertTest \ sql.txt";
String = strTableName "Student";
/ * in each field information "," split
* to each of the data "|" delimited
* per 100,000 a transaction data * /
String SQL = string.Format ( "the BULK the INSERT 0 { the FROM} '{}. 1' the WITH (the FIELDTERMINATOR = ',', ROWTERMINATOR = '|', the BATCHSIZE = 50000) ", strTableName, strFilePath);
the DBHelper DBHelper the DBHelper new new = ();
dbHelper.Excute (SQL);
}
// / <Summary>
/// normal inserted test
/// </ Summary>
Private static void CommonInsertTest ()
{
int I =. 1;
while (i <= 500000)
{
string sqlInsert = string.Format("insert into Student1(id,Name,Age) values({0},'test{0}',{0})", i);
new DBHelper().Excute(sqlInsert);
i++;
}
}
Fourth Step: Main Main function calls and ordinary bulk insert insertion method, and by calculating the execution time Stopwatch, Pragram complete code as follows:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using QYH.BlukInsertTest.FileMange;
using QYH.BlukInsertTest.DataBase;
using System.Diagnostics;
namespace QYH.BlukInsertTest
{
class Program
{
static void Main(string[] args)
{
//用于生成海量数据
//GenerateTestData();
Stopwatch stopwatch = Stopwatch.StartNew();
try
{
BulkInsertTest();
}
catch (Exception)
{
//throw;
}
stopwatch.Stop();
string strResult = "批量插入耗时：" + stopwatch.ElapsedMilliseconds.ToString();
Stopwatch1 = Stopwatch.StartNew The Stopwatch ();
CommonInsertTest ();
stopwatch1.Stop ();
String str1Result = "Common Insert Processed:" + stopwatch1.ElapsedMilliseconds.ToString ();
String strTestResult = "Result";
File.WriteTextAsync (strResult + "\ R & lt \ n-" + str1Result, strTestResult);
//Console.Read ();
}
/// <Summary>
/// bulk insert test
/// </ Summary>
Private static void BulkInsertTest ()
{
String strFilePath = @ "D: \ learning \ ASP.NET \ QYH.BlukInsertTest \ sql.txt";
String strTableName = "Student";
/ * information for each field to "," split
* each piece of data to | delimiter ""
* 100 000 data per transaction * /
string sql = string.Format("BULK INSERT {0} FROM '{1}' WITH (FIELDTERMINATOR = ',',ROWTERMINATOR ='|',BATCHSIZE = 50000)", strTableName, strFilePath);
DBHelper dbHelper = new DBHelper();
dbHelper.Excute(sql);
}
/// <summary>
/// 普通插入测试
/// </summary>
private static void CommonInsertTest()
{
int i = 1;
while (i <= 500000)
{
string sqlInsert = string.Format("insert into Student1(id,Name,Age) values({0},'test{0}',{0})", i);
new DBHelper().Excute(sqlInsert);
i++;
}
}
/// <summary>
/// 生成测试数据
/// </summary>
private static void GenerateTestData()
{
string fileName = "sql";
int i = 1;
while (i <= 500000)
{
string strInsert = string.Format("{0},'test{0}',{0}|", i);
File.AppendText(strInsert, fileName);
i++;
}
}
}
}
Example also uses two helper classes, DBHelper.cs and File.cs, since only for demonstration, so writing is very simple, where the file path is hard-coded, and can be replaced by the actual path.
DBHelper.cs
using System;
using System.Collections.Generic;
using System.Data.SqlClient;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace QYH.BlukInsertTest.DataBase
{
public class DBHelper
{
public string connectionString = "Server=.;Database=QYHDB;User ID=sa;Password=123456;Trusted_Connection=False;";
public void Excute(string sql)
{
SqlConnection conn = new SqlConnection(connectionString);
SqlCommand command = new SqlCommand();
command.CommandTimeout = 0;
command.Connection = conn;
command.CommandText = sql;
conn.Open();
command.ExecuteNonQuery();
conn.Close();
}
}
}
File.cs
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace QYH.BlukInsertTest.FileMange
{
public class File
{
public static string strFilePath = @"D:\学习\ASP.NET\QYH.BlukInsertTest";
public static async void WriteTextAsync(string text, string fileName)
{
using (StreamWriter outputFile = new StreamWriter(strFilePath + @"\" + fileName + ".txt"))
{
await outputFile.WriteAsync(text);
}
}
public static void AppendText(string text, string fileName)
{
// Append text to an existing file named "WriteLines.txt".
using (StreamWriter outputFile = new StreamWriter(strFilePath + @"\" + fileName + ".txt",true))
{
outputFile.WriteLine(text);
}
}
}
}
Everything is ready, start running, as follows:
Wherein units of milliseconds , we can see from the results 500,000 BULK INSER inserted data need not three seconds , whereas the ordinary one by inserting it takes more than 20 minutes