怎么用c#代码在sql中建立新的数据库

首先，我们在程序中动态地创建SQL Server数据库。
我们将数据库创建在C:\mysql目录下，所以读者要练习该实例的话得先在C:下创建一个名为mysql的文件夹，否则会出错！创建数据库的关键是函数中的sql对象，通过该对象我们指定了数据库文件的一些基本属性。之后，我们新创建了一个SqlCommand对象，通过该对象我们 就实际完成了对数据库的操作。函数的实现如下：
private void button1_Click(object sender, System.EventArgs e)
{
// 打开数据库连接
if( conn.State != ConnectionState.Open)
conn.Open();
string sql = "CREATE DATABASE mydb ON PRIMARY"
+"(name=test_data, filename = 'C:\\mysql\\mydb_data.mdf', size=3,"
+"maxsize=5, filegrowth=10%) log on"
+"(name=mydbb_log, filename='C:\\mysql\\mydb_log.ldf',size=3,"
+"maxsize=20,filegrowth=1)";
cmd = new SqlCommand(sql, conn);
try { cmd.ExecuteNonQuery(); }
catch(SqlException ae)
{
MessageBox.Show(ae.Message.ToString());
}
}
其次，我们通过CREATE TABLE语句创建基本表，并向该表中添加4条数据。函数的实现如下：
private void button2_Click(object sender, System.EventArgs e)
{
// 打开数据库连接
if( conn.State == ConnectionState.Open)
conn.Close();
ConnectionString ="Integrated Security=SSPI;" + "Initial Catalog=mydb;" + "Data Source=localhost;";
conn.ConnectionString = ConnectionString;
conn.Open();
sql = "CREATE TABLE myTable"+ "(myId INTEGER CONSTRAINT PKeyMyId PRIMARY KEY,"
+ "myName CHAR(50), myAddress CHAR(255), myBalance FLOAT)";
cmd = new SqlCommand(sql, conn);
try {
cmd.ExecuteNonQuery(); // 向表中添加记录
sql = "INSERT INTO myTable(myId, myName, myAddress, myBalance) "+ "VALUES (1001, 'Puneet Nehra', 'A 449 Sect 19, DELHI', 23.98 ) " ;
cmd = new SqlCommand(sql, conn);
cmd.ExecuteNonQuery();
sql = "INSERT INTO myTable(myId, myName,myAddress, myBalance) "+ "VALUES (1002, 'Anoop Singh', 'Lodi Road, DELHI', 353.64) " ;
cmd = new SqlCommand(sql, conn);
cmd.ExecuteNonQuery();
sql = "INSERT INTO myTable(myId, myName, myAddress, myBalance) "+ "VALUES (1003, 'Rakesh M', 'Nag Chowk, Jabalpur M.P.', 43.43) " ;
cmd = new SqlCommand(sql, conn);
cmd.ExecuteNonQuery();
sql = "INSERT INTO myTable(myId, myName, myAddress, myBalance) "+ "VALUES (1004, 'Madan Kesh', '4th Street, Lane 3, DELHI', 23.00) " ;
cmd = new SqlCommand(sql, conn);
cmd.ExecuteNonQuery(); }
catch(SqlException ae) { MessageBox.Show(ae.Message.ToString()); }
}
完成此操作后，我们可以打开SQL SERVER的企业管理器，查看是否有我们创建的数据库和基本表。

一般建数据库都是在数据库软件中新建的，然后再连接数据库