C# 使用连接器/NET编程创建数据库?
如何使用connector/net编程创建数据库?为什么下面的方法不起作用C# 使用连接器/NET编程创建数据库?,c#,mysql,database,C#,Mysql,Database,如何使用connector/net编程创建数据库?为什么下面的方法不起作用 string connStr = "server=localhost;user=root;port=3306;password=mysql;"; MySqlConnection conn = new MySqlConnection(connStr); MySqlCommand cmd; string s0; try { conn.Open();
string connStr = "server=localhost;user=root;port=3306;password=mysql;";
MySqlConnection conn = new MySqlConnection(connStr);
MySqlCommand cmd;
string s0;
try
{
conn.Open();
s0 = "CREATE DATABASE IF NOT EXISTS `hello`;";
cmd = new MySqlCommand(s0, conn);
conn.Close();
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
您可能需要执行MySqlCommand。现在您只需创建一个,但它不会执行您的查询 试试这个:
conn.Open();
s0 = "CREATE DATABASE IF NOT EXISTS `hello`;";
cmd = new MySqlCommand(s0, conn);
cmd.ExecuteNonQuery();
conn.Close();
您需要执行该命令,并确保正确处置对象:
string connStr = "server=localhost;user=root;port=3306;password=mysql;";
using (var conn = new MySqlConnection(connStr))
using (var cmd = conn.CreateCommand())
{
conn.Open();
cmd.CommandText = "CREATE DATABASE IF NOT EXISTS `hello`;";
cmd.ExecuteNonQuery();
}
执行命令并尝试此功能
public void createDatabase(string server, string port, string database, string username, string password)
{
string connectionstring = string.Format("Server = {0}; Port ={1}; Uid = {2}; Pwd = {3}; pooling = true; Allow Zero Datetime = False; Min Pool Size = 0; Max Pool Size = 200; ", server, port, username, password);
using (var con = new MySqlConnection { ConnectionString = connectionstring })
{
using (var command = new MySqlCommand { Connection = con })
{
if (con.State == ConnectionState.Open)
con.Close();
try
{
con.Open();
}
catch (MySqlException ex)
{
msgErr(ex.Message + " connection error.");
return;
}
try
{
command.CommandText = @"CREATE DATABASE IF NOT EXISTS @database";
command.Parameters.AddWithValue("@database", database);
command.ExecuteNonQuery();//Execute your command
}
catch (MySqlException ex)
{
msgErr(ex.Message + " sql query error.");
return;
}
}
}
}
这在VS2013中有效吗?还是必须先附加一些Dll?我在c#程序中尝试过,但没有成功。必须在数据库名称周围使用“而不是”。感谢您在VS 2013中完成这项工作,还是您必须先附加一些Dll?没有格式。这根本无助于解决问题。请删除或改进您的答案,谢谢。
Imports MySql.Data.MySqlClient
Public Class Form1
Private dBf As String = "Empresa"
Private str As String = "Server = localhost; uid=root; pwd=;Database=mysql; pooling=false;"
Private Cmd As MySqlCommand
Private Con As New MySqlConnection(str)
Private Sub Form1_Load() Handles MyBase.Load
Try
Con.Open()
Cmd = New MySqlCommand("Create Database If Not exists " + dBf, Con)
Cmd.ExecuteNonQuery() : Con.ChangeDatabase(dBf)
Cmd = Con.CreateCommand
Cmd.CommandText = "CREATE TABLE Empleado" &
"(Id Char(10) COLLATE utf8_spanish_ci Not Null," &
"name VarChar(50) COLLATE utf8_spanish_ci Not Null," &
"email VarChar(50) COLLATE utf8_spanish_ci Not Null," &
"website VarChar(50) COLLATE utf8_spanish_ci Not Null," &
"Primary Key(id)) ENGINE=MyISAM"
Cmd.ExecuteNonQuery()
MsgBox("Registros, ok!!!") : Con.Close()
Catch ex As Exception
MsgBox(Err.Description)
End Try
End Sub
End Class