这篇文章转载自：阴立坤的QQ空间 [csharp] public class SqlCode { ///

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public static SqlConnection DBCon() { return new SqlConnection(@“server=JACK-PCSQLEXPRESS;database=test;uid=sa;pwd=jack123”); //Sql身份验证 //Integrated Security = SSPI/Windwos 身份验证 } ///

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Sql查询语句（Select） ///

public static DataSet Query(string SQLString) { using (SqlConnection conn = DBCon()) { DataSet ds = new DataSet(); try { conn.Open(); SqlDataAdapter command = new SqlDataAdapter(SQLString, conn); command.Fill(ds, “ds”); command.Dispose(); conn.Close(); } catch (System.Data.SqlClient.SqlException ex) { throw new Exception(ex.Message); } return ds; }//当connection对象执行到这里时，即被释放，帮助内存回收 } ///

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包括 Insert、Delete、Update public static void InOrDelOrUp(string Sql)//插入数据/删除数据/更新数据 { SqlConnection conn = DBCon(); conn.Open(); SqlCommand cmd = new SqlCommand(Sql, conn); cmd.ExecuteNonQuery(); cmd.Dispose(); conn.Close(); } ///

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public static bool CheckName(string Username) { SqlConnection conn = DBCon(); conn.Open(); SqlCommand cmd = new SqlCommand(“select * from stu where sName="" + Username + """, conn); cmd.ExecuteNonQuery(); if (null != cmd.ExecuteScalar()) { cmd.Dispose(); conn.Close(); return false; } else { cmd.Dispose(); conn.Close(); return true; } } } [/csharp]