C # how to operate SQL dynamically!

Just written to Program You need to add databases and tables to the SQL statements. The information you are looking for on the Internet is not comprehensive. I have sorted it out. The detailed information is as follows:
// __________________ Create a database ____________________
String connectionstring = "Data Source = localhost; Integrated Security = true; pooling = false ";
Sqlconnection conn = new sqlconnection (connectionstring );
Conn. open ();
SQL = "CREATE DATABASE clsky on primary (name = ABC, filename = 'e: \ clsky. MDF ')";
Sqlcommand cmd = new sqlcommand (SQL, Conn );
Cmd. executenonquery ();
MessageBox. Show ("the database is created successfully! ");
//_________________________________________________

// ________________ Create a table ___________________________

String connectionstring1 = "Data Source = localhost; initial catalog = clsky; Integrated Security = true; pooling = false ";
Sqlconnection conn1 = new sqlconnection (connectionstring1 );
Conn1.open ();
SQL = "CREATE TABLE clsky" +
"(ID integer constraint pkeymyid primary key," +
"Name char (50), address char (255), balance float )";
Sqlcommand cmd1 = new sqlcommand (SQL, conn1 );
Statement 1.executenonquery ();
MessageBox. Show ("the database is created successfully! ");
//__________________________________________________

// _______________ Delete a table _____________

SQL = "Drop table clsky ";
Sqlcommand cmd2 = new sqlcommand (SQL, conn1 );
Listen 2.executenonquery ();
MessageBox. Show ("Table deleted! ");
Conn1.close ();
Conn. Close ();
//_________________________________
If you want to delete this database, you can use:
String connectionstring = "Data Source = localhost; Integrated Security = true; pooling = false ";
Sqlconnection conn = new sqlconnection (connectionstring );
Conn. open ();
String SQL = "DROP DATABASE clsky ";
Sqlcommand cmd = new sqlcommand (SQL, Conn );
Cmd. executenonquery ();