C# 创建通用增删改查代码

//引入命名空间
using System.Data;
public static Dictionary select(string sql)
    {
        string conn = Create();//方法见上文
        SqlDataAdapter da = new SqlDataAdapter(sql, conn);
        DataTable dt = new DataTable();
        da.Fill(dt);
        if (dt.Rows.Count == 0)
        {
            return null;
        }
        DataRow row = dt.Rows[0];
        Dictionary dic = new Dictionary();
        foreach (dataColumn item in dt.Columns)
        {
            dic.add(item.ColumnsName, row[item.ColumnsName])
        }
        return dic;
    }

    //查询多条数据
    public static Datable Selects(string sql)
    {
        try
        {
            SqlConnection conn = Create();
            SqlCommand com = new SqlCommand();
            com.Connection = conn;
            com.Command = sql;
            SqlDataAdpter da = new SqlDataAdapter(com);
            Dataset ds = new DataSet();
            da.Fill(ds);
            return ds.Tables[0];
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }
    //执行一条SQL语句，增删改都可以用
    public static int ExecutionSQl(string sql，Sqlconnection conn = null)
    {
        conn = conn = null ? Create() : conn;
        try
        {
            conn.open();
            SqlCommand com = new SqlCommand(sql, conn);
            return com.ExecutionNonQuery()；
}
        catch (Exception ex)
        {
            console.write(ex.Message);
            return -1;
        }
        finally
        {
            conn.colse();
        }
    }
    //保存修改带参数可用此方法
    public static int ExecutionPar(string sql, SqlParameter[] sqlparameter)
    {
        SqlConnection conn = Create();
        SqlCommand com = null;
        try
        {
            conn.open();
            com = new SqlCommand();
            com.Connection = conn;
            com.CommandText = sql;
            return com.ExexutionNonQuery();
        }
        catch (Execption ex)
        {
            console.WriteLine(ex, Message);
            return -1;
        }
        finlly{
            com.Parameter.Clear();
            conn.Close();
        }
    }