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首先创建了一个SQL Server数据库作为测试的数据库，建立表并填入测试数据
数据库：SQL Server
数据库名：Blog
表名：Test
注：数据库的连接可以使用“dbl”文件测试，具体使用百度即可。
1.将数据库的数据全部查询到datagridview
语句：select * from Test
1 private void button1_Click(object sender, EventArgs e) 2 { 3 string connstr = "Data Source=LONG-PC\\LONG;Initial Catalog=Blog;User ID=long;Password=longtao"; 4 string cmdstr="select * from Test"; 5 6 SqlConnection conn = new SqlConnection(connstr); 7 conn.Open(); 8 9 SqlCommand cmd = new SqlCommand(); 10 cmd.CommandText = cmdstr; 11 cmd.Connection = conn; 12 SqlDataAdapter adap = new SqlDataAdapter(cmd); 13 DataSet ds = new DataSet(); 14 adap.Fill(ds); 15 dataGridView1.DataSource = ds.Tables[0].DefaultView; 16 }
2.查询数据库的部分数据并显示到datagridview
语句： string cmdstr = "select 姓名,年龄 from Test";
1 private void button2_Click(object sender, EventArgs e) 2 { 3 string connstr = "Data Source=LONG-PC\\LONG;Initial Catalog=Blog;User ID=long;Password=longtao"; 4 string cmdstr = "select 姓名,年龄 from Test"; 5 6 SqlConnection conn = new SqlConnection(connstr); 7 conn.Open(); 8 9 SqlCommand cmd = new SqlCommand(); 10 cmd.CommandText = cmdstr; 11 cmd.Connection = conn; 12 SqlDataAdapter adap = new SqlDataAdapter(cmd); 13 DataSet ds = new DataSet(); 14 adap.Fill(ds); 15 dataGridView1.DataSource = ds.Tables[0].DefaultView; 16 }
3.使用列别名显示数据
语句： string cmdstr = "select 姓名 as name,年龄 as age from Test";
注：语句中的“as”关键词，可以使用空格代替
1 private void button3_Click(object sender, EventArgs e) 2 { 3 string connstr = "Data Source=LONG-PC\\LONG;Initial Catalog=Blog;User ID=long;Password=longtao"; 4 string cmdstr = "select 姓名 as name,年龄 as age from Test"; 5 6 SqlConnection conn = new SqlConnection(connstr); 7 conn.Open(); 8 9 SqlCommand cmd = new SqlCommand(); 10 cmd.CommandText = cmdstr; 11 cmd.Connection = conn; 12 SqlDataAdapter adap = new SqlDataAdapter(cmd); 13 DataSet ds = new DataSet(); 14 adap.Fill(ds); 15 dataGridView1.DataSource = ds.Tables[0].DefaultView; 16 }
4.使用列计算
语句：string cmdstr = "select 姓名,年龄,语文,数学,英语,语文+数学+英语 as 总分 from Test";
1 private void button4_Click(object sender, EventArgs e) 2 { 3 string connstr = "Data Source=LONG-PC\\LONG;Initial Catalog=Blog;User ID=long;Password=longtao"; 4 string cmdstr = "select 姓名,年龄,语文,数学,英语,语文+数学+英语 as 总分 from Test"; 5 6 SqlConnection conn = new SqlConnection(connstr); 7 conn.Open(); 8 9 SqlCommand cmd = new SqlCommand(); 10 cmd.CommandText = cmdstr; 11 cmd.Connection = conn; 12 SqlDataAdapter adap = new SqlDataAdapter(cmd); 13 DataSet ds = new DataSet(); 14 adap.Fill(ds); 15 dataGridView1.DataSource = ds.Tables[0].DefaultView; 16 }
5.限定查询数值范围大小
语句：string cmdstr = "select 姓名,年龄,语文,数学,英语,语文+数学+英语 as 总分 from Test where (语文+数学+英语)>215";
1 private void button5_Click(object sender, EventArgs e) 2 { 3 string connstr = "Data Source=LONG-PC\\LONG;Initial Catalog=Blog;User ID=long;Password=longtao"; 4 string cmdstr = "select 姓名,年龄,语文,数学,英语,语文+数学+英语 as 总分 from Test where (语文+数学+英语)>215"; 5 6 SqlConnection conn = new SqlConnection(connstr); 7 conn.Open(); 8 9 SqlCommand cmd = new SqlCommand(); 10 cmd.CommandText = cmdstr; 11 cmd.Connection = conn; 12 SqlDataAdapter adap = new SqlDataAdapter(cmd); 13 DataSet ds = new DataSet(); 14 adap.Fill(ds); 15 dataGridView1.DataSource = ds.Tables[0].DefaultView; 16 }
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原文地址：http://www.cnblogs.com/imstrive/p/4563799.html
