【发布时间】:2020-05-14 19:20:36
【问题描述】:
我想创建基于迁移的 Visual Basic 应用程序,用于将 MySQL 数据库表迁移到 MS SQL Server 2014,以便通过一键单击事件轻松完成,它将开始迁移您要迁移的任何数据库的数据
这是我编写的主要代码,但是当我想在 MySqlCommand 参数中连接两个连接时,这怎么可能
private void Start_Click(object sender, EventArgs e)
{
//MS SQL Connection server
string connectionString;
SqlConnection MSSQL;
connectionString = @"Data Source=DESKTOP-IF12M9R;Initial Catalog=utility;User ID=sa;Password=mysql";
MSSQL = new SqlConnection(connectionString);
MSSQL.Open();
MessageBox.Show("Connection Open of MS SQL !");
//MySQL server Connectivity
string connStr = "server=localhost;user=root;database=utility;port=3306;password=''";
MySqlConnection conn = new MySqlConnection(connStr);
try
{
MessageBox.Show("Connecting to MySQL...");
conn.Open();
MessageBox.Show("Connection open of MySQL!");
string sql = "SELECT * FROM userial";
MessageBox.Show(sql);
MySqlCommand cmd = new MySqlCommand(sql, conn);
MySqlDataReader rdr = cmd.ExecuteReader();
while (rdr.Read())
{
MessageBox.Show(rdr[0] + " -- " + rdr[1] + " -- " + rdr[2] + " -- " + rdr[3]);
}
rdr.Close();
string mytoms = "IF EXISTS (SELECT * FROM sys.objects so JOIN sys.schemas sc ON so.schema_id = sc.schema_id WHERE so.name = N'userial' AND sc.name = N'utility' AND type in (N'U')) BEGIN DECLARE @drop_statement nvarchar(500) DECLARE drop_cursor CURSOR FOR SELECT 'alter table ' + quotename(schema_name(ob.schema_id)) + '.' + quotename(object_name(ob.object_id)) + ' drop constraint ' + quotename(fk.name) FROM sys.objects ob INNER JOIN sys.foreign_keys fk ON fk.parent_object_id = ob.object_id WHERE fk.referenced_object_id = ( SELECT so.object_id FROM sys.objects so JOIN sys.schemas sc ON so.schema_id = sc.schema_id WHERE so.name = N'userial' AND sc.name = N'utility' AND type in (N'U')) OPEN drop_cursor FETCH NEXT FROM drop_cursor INTO @drop_statement WHILE @@FETCH_STATUS = 0 BEGIN EXEC(@drop_statement) FETCH NEXT FROM drop_cursor INTO @drop_statement END CLOSE drop_cursor DEALLOCATE drop_cursor DROP TABLE[utility].[userial] END GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE TABLE [utility].[userial] ([SerialID] int NOT NULL, [SerialNo] varchar(50) NOT NULL, [DateTime] datetime2(0) NOT NULL, [Result] varchar(4) NOT NULL WITH(DATA_COMPRESSION = NONE) GO IF EXISTS(SELECT* FROM sys.objects so JOIN sys.schemas sc ON so.schema_id = sc.schema_id WHERE so.name = N'PK_userial_SerialID' AND sc.name = N'utility' AND type in (N'PK')) ALTER TABLE[utility].[userial] DROP CONSTRAINT[PK_userial_SerialID] GO ALTER TABLE[utility].[userial] ADD CONSTRAINT[PK_userial_SerialID] PRIMARY KEY CLUSTERED([SerialID] ASC) GO ALTER TABLE[utility].[userial] ADD DEFAULT getdate() FOR[DateTime] GO";
MessageBox.Show(mytoms);
MySqlCommand cmd1 = new MySqlCommand(mytoms , conn, MSSQL);
MySqlDataReader rdr1 = cmd1.ExecuteReader();
while (rdr1.Read())
{
MessageBox.Show(rdr1[0] + " -- " + rdr1[1] + " -- " + rdr1[2] + " -- " + rdr1[3]);
}
rdr.Close();
}
catch (Exception ex)
{
Console.WriteLine(ex.ToString());
}
}
现在主要问题在这里
MySqlCommand cmd1 = new MySqlCommand(mytoms , conn, MSSQL);
有什么解决办法吗?
【问题讨论】:
-
你应该声明一个专用于 sql server 的连接和另一个专用于 mysql 的连接
-
你不应该在
MySqlCommand中有两个连接(我认为这完全不可能)。只需在while (rdr.Read())循环中使用适当的 SQL 命令执行cmd1.ExecuteNonQuery()。
标签: c# mysql sql-server database-migration data-migration