前面用过Access的通讯录,下面用一个SQLserver的通讯录。 首先,在SQL2012中建立一个表,插入一个记录: use Salesgocreate table txl( tID int identity(10000,1) primary key, tName varchar(50) not null, tEmail varchar(50), tMobile char(11), tHomePh
前面用过Access的通讯录,下面用一个SQLserver的通讯录。
首先,在SQL2012中建立一个表,插入一个记录:
use Sales go create table txl ( tID int identity(10000,1) primary key, tName varchar(50) not null, tEmail varchar(50), tMobile char(11), tHomePhone varchar(12), tMemo varchar(2000) --备注 ) insert into txl values('令狐冲','yms@sohu.com','13681246528','62349087','一个剑客')
注:identity(seed,incre)第一个表示起点,第二表示增量。10000,1表示记录从10000开始,每一个记录数据增加加1.
所以第二条记录的标号就是10001.
下面用VB.net对其插入记录,并显示。
注意:SQL语句中的单引号
Imports System.Data.SqlClient Public Class Form1 Dim cn As SqlConnection Dim cmd As SqlCommand Dim da As SqlDataAdapter Dim ds As DataSet Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click Try cn = New SqlConnection("Data Source=.;Initial Catalog=Sales;Integrated Security=False;User ID=sa;Password=123456;") cn.Open() cmd = New SqlCommand("insert into txl values('" & TextBox1.Text & "','" & TextBox2.Text & "','" & TextBox3.Text & "','" & TextBox4.Text & "','" & TextBox5.Text & "')", cn) cmd.ExecuteNonQuery() cn.Close() MessageBox.Show("插入成功") Catch ex As Exception MessageBox.Show(ex.ToString & cmd.CommandText) End Try End Sub Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click cn = New SqlConnection("Data Source=.;Initial Catalog=Sales;Integrated Security=False;User ID=sa;Password=123456;") da = New SqlDataAdapter("select * from txl", cn) ds = New DataSet() da.Fill(ds, "txl") DataGridView1.DataSource = ds.Tables("txl") cn.Close() End Sub Private Sub Button2_Click(sender As Object, e As EventArgs) Try cn = New SqlConnection("Data Source=.;Initial Catalog=Sales;Integrated Security=False;User ID=sa;Password=123456;") cn.Open() cmd = New SqlCommand("insert into txl values('" & TextBox1.Text & "','" & TextBox2.Text & "','" & TextBox3.Text & "','" & TextBox4.Text & "','" & TextBox5.Text & "')", cn) cmd.ExecuteNonQuery() cn.Close() MessageBox.Show("插入成功") Catch ex As Exception MessageBox.Show(ex.ToString & cmd.CommandText) End Try End Sub End Class

由引我们学习了Access和SQlserver查看记录和修改记录的例子。
一,查询与非查询的操作。
二,存储过程的操作,参数是如何添加的。

MySQLviewshavelimitations:1)Theydon'tsupportallSQLoperations,restrictingdatamanipulationthroughviewswithjoinsorsubqueries.2)Theycanimpactperformance,especiallywithcomplexqueriesorlargedatasets.3)Viewsdon'tstoredata,potentiallyleadingtooutdatedinforma

ProperusermanagementinMySQLiscrucialforenhancingsecurityandensuringefficientdatabaseoperation.1)UseCREATEUSERtoaddusers,specifyingconnectionsourcewith@'localhost'or@'%'.2)GrantspecificprivilegeswithGRANT,usingleastprivilegeprincipletominimizerisks.3)

MySQLdoesn'timposeahardlimitontriggers,butpracticalfactorsdeterminetheireffectiveuse:1)Serverconfigurationimpactstriggermanagement;2)Complextriggersincreasesystemload;3)Largertablesslowtriggerperformance;4)Highconcurrencycancausetriggercontention;5)M

Yes,it'ssafetostoreBLOBdatainMySQL,butconsiderthesefactors:1)StorageSpace:BLOBscanconsumesignificantspace,potentiallyincreasingcostsandslowingperformance.2)Performance:LargerrowsizesduetoBLOBsmayslowdownqueries.3)BackupandRecovery:Theseprocessescanbe

Adding MySQL users through the PHP web interface can use MySQLi extensions. The steps are as follows: 1. Connect to the MySQL database and use the MySQLi extension. 2. Create a user, use the CREATEUSER statement, and use the PASSWORD() function to encrypt the password. 3. Prevent SQL injection and use the mysqli_real_escape_string() function to process user input. 4. Assign permissions to new users and use the GRANT statement.

MySQL'sBLOBissuitableforstoringbinarydatawithinarelationaldatabase,whileNoSQLoptionslikeMongoDB,Redis,andCassandraofferflexible,scalablesolutionsforunstructureddata.BLOBissimplerbutcanslowdownperformancewithlargedata;NoSQLprovidesbetterscalabilityand

ToaddauserinMySQL,use:CREATEUSER'username'@'host'IDENTIFIEDBY'password';Here'showtodoitsecurely:1)Choosethehostcarefullytocontrolaccess.2)SetresourcelimitswithoptionslikeMAX_QUERIES_PER_HOUR.3)Usestrong,uniquepasswords.4)EnforceSSL/TLSconnectionswith

ToavoidcommonmistakeswithstringdatatypesinMySQL,understandstringtypenuances,choosetherighttype,andmanageencodingandcollationsettingseffectively.1)UseCHARforfixed-lengthstrings,VARCHARforvariable-length,andTEXT/BLOBforlargerdata.2)Setcorrectcharacters


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),

SublimeText3 Chinese version
Chinese version, very easy to use

WebStorm Mac version
Useful JavaScript development tools

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver Mac version
Visual web development tools
