Jan
4
1. 先using System.Data.SqlClient;
2. 在函数中,定义SqlConnection:
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- SqlConnection conn = new SqlConnection("...连接字串...");
3. 紧接着,定义SqlCommand来执行SQL语句:
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- string s = "select * from tableA";
- SqlCommand q = new SqlCommand(s, conn);
- conn.Open();
4. 定义SqlDataReader来接受返回的记录,除了用ExecuteReader返回SqlDataReader,还有ExecuteNonQuery,ExecuteScalar返回简单值的应用,详见MSDN.用完以后,记得Close这个SqlDataReader,不然以后使用SqlCommand时会有麻烦.
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- SqlDataReader r = q.ExecuteReader();
- if (r.Read())
- {
- Response.Write(r[0].ToString().Trim());
- }
- r.Close();
5.如果需要再次查询,可以使用同一个SqlCommand,只要记得前面关闭了SqlDataReader,使SqlCommand重获自由.
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- q.CommandText = "update tableA set ColA='A' where ColB='B'";
- q.ExecuteNonQuery();
6. 全部用完以后,关闭SqlConnection
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- conn.Close();
