T-SQL的基础代码

1、建立连接数据库

1 using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.Data.SqlClient;

namespace 连接数据库
{
class Program
{
static void Main(string[] args)
{    //要连接数据库就要一个连接字符串，连接数据库的实例名，数据库名，用户名和密码
//string sqlConn = @"server=.\sqlexpress;database=MyDataBase;uid=sa;pwd=123";
//string sqlConn = @"server=.;database=MyDataBase;Integrated security=true";//Windonws集成登录

//打开连接
string sqlConn = @"server=.\sqlexpress;database=MyDataBase;uid=sa;pwd=123";
SqlConnection conn = new SqlConnection(sqlConn);

conn.Open();
Console.WriteLine("OKS");
string sts = @"create table UseLogin (id int identity(1,1) primary key,name nvarchar(10),pwd nvarchar(16) check(len(pwd) between 6 and 16))";
SqlCommand cmd = new SqlCommand(sts, conn);
using (cmd)
{
//cmd.ExecuteNonQuery();
}
using (conn)
{
SqlCommand cmd1 = new SqlCommand("insert into UseLogin (name,pwd) values('找2','1231234');",conn);
using (cmd)
{
int res = cmd1.ExecuteNonQuery();
Console.WriteLine("{0}行受影响",res);
}
}
Console.ReadKey();
}
}
}

2、查询

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.SqlClient;

namespace 查找
{
class Program
{
static void Main(string[] args)
{
string sqlConn = @"server=.;database=MyDataBase;Integrated security=true";
string sql = @"select count(*) from uselogin where name='张三'";
using (SqlConnection conn = new SqlConnection(sqlConn))
{
using (SqlCommand cmd = new SqlCommand(sql, conn))
{
if (conn.State == System.Data.ConnectionState.Closed)
{
conn.Open();
}
int res = Convert.ToInt32(cmd.ExecuteScalar());
Console.WriteLine("找到{0}个", res);
}
}
Console.ReadKey();
}
}