/// EXISTS
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="source"></param>
/// <param name="query"></param>
/// <returns></returns>
public static int Delete<T>(this System.Data.Linq.Table<T> source, Expression<Func<T, bool>> query)
where T : class
{
if (source == null)
throw new ArgumentException("source");
if (query == null)
throw new ArgumentException("query");
//query = t => true;
//为空DELETE FROM [dbo].[test] 全删除;个人觉得为空全删除,很不人道,所以还是抛异常
System.Data.Linq.DataContext db = source.Context;
DbCommand cmd= db.GetCommand(source.Where(query));
string queryStr = cmd.CommandText;
string sql = "DELETE FROM " + source.Context.Mapping.GetTable(typeof(T)).TableName + " WHERE EXISTS(" + queryStr+")";
List<object> dbparams = new List<object>();
foreach (SqlParameter item in cmd.Parameters)
{
SqlParameter p = new SqlParameter(item.ParameterName, item.SqlDbType, item.Size);
p.Value = item.Value;
dbparams.Add(item.Value);
}
cmd = null;
return db.ExecuteCommand(sql, dbparams.ToArray());
}