Linq to SQL 基础篇

LinqtoSqlDataContext Linq = new LinqtoSqlDataContext(ConfigurationManager.ConnectionStrings["sz_imt20131024pmConnectionString"].ConnectionString);

DataContext对象

var query = from usersTable in Linq.UsersTable
                        where usersTable.Uid > &&usersTable.Username.StartsWith("张")
                        orderby usersTable.Uid descending
                        select new
                        {
                            Uid = usersTable.Uid,
                            Username = usersTable.Username
                        };
或者
 
var query= Linq.UsersTable.Where(a => a.Uid >  && a.Username.StartsWith("张"));

查询

UsersTable user = new UsersTable
            {
                Username = "小张",
                Sex = "女",
                Password = ""
            };
 
            Linq.UsersTable.InsertOnSubmit(user);
            Linq.SubmitChanges();

添加

UsersTable UT = Linq.UsersTable.Single(a => a.Uid == );
            UT.Username = "小明";
            Linq.SubmitChanges();

更新

UsersTable UT = Linq.UsersTable.Single(a => a.Uid == );
            Linq.UsersTable.DeleteOnSubmit(UT);
            Linq.SubmitChanges();

删除

//输出参数
string name="";
 
Linq:DataContext对象；PROC_SELECTBYUID:存储过程名称
var query = Linq.PROC_SELECTBYUID(ref name);

调用存储过程

//字符串数组
string[] starts = new string[];
            ParameterExpression c = Expression.Parameter(typeof(K_SysModuleNode), "c");
            Expression condition = Expression.Constant(false);
            foreach (string item in starts)
            {
                Expression con = Expression.Call(
                    Expression.Property(c, typeof(K_SysModuleNode).GetProperty("NodeName")),
                    typeof(string).GetMethod("StartsWith", new Type[] { typeof(string) }),
                    Expression.Constant(item)
                    );
                condition = Expression.Or(con,condition);
            }
            Expression<Func<K_SysModuleNode, bool>> end =
                Expression.Lambda<Func<K_SysModuleNode, bool>>(condition, new ParameterExpression[] { c });
 
            var query = Linq.K_SysModuleNode.Where(end);

Linq之动态条件查询