本篇文章給大家帶來的內容是關于MySQL如何通過實例化對象參數查詢數據 ？（源代碼），有一定的參考價值，有需要的朋友可以參考一下，希望對你有所幫助。
public static string QueryByEntity<T>(T t) where T : new(){ string resultstr = string.Empty; MySqlDataReader reader = null; try { Type type = typeof(T); PropertyInfo[] properties = type.GetProperties(); string select = string.Format("Select * from {0} {1}", type.Name, "{0}"); string where = string.Empty; foreach (PropertyInfo property in properties) { var value = t.GetPropertyValue<T>(property); if (value != null && !value.Equals(property.GetDefaultValue())) { if (string.IsNullOrEmpty(where)) { where = string.Format(" where {0}='{1}' ", property.Name, value); } else { where = string.Format(" {0} and {1} = '{2}' ", where, property.Name, value); } } } select = string.Format(select, where); MySqlConnection connection = OpenConnection(); if (connection == null) return resultstr; MySqlCommand _sqlCom = new MySqlCommand(select, connection); reader = _sqlCom.ExecuteReader(); List<T> tList = new List<T>(); while (reader.Read()) { T t1 = new T(); foreach (PropertyInfo property in properties) { if (!string.IsNullOrEmpty(reader[property.Name].ToString())) { property.SetMethod.Invoke(t1, new object[] { reader[property.Name] }); } } tList.Add(t1); } resultstr = JsonConvert.SerializeObject(tList); } catch (Exception ex) { Logging.Error(string.Format("查詢數據庫失敗，{0}", ex.Message)); } finally { if (reader != null) { reader.Close(); reader.Dispose(); } } return resultstr;}internal static class ObjectExtend{ public static object GetPropertyValue<T>(this object obj, PropertyInfo property) { Type type = typeof(T); PropertyInfo propertyInfo = type.GetProperty(property.Name); if (propertyInfo != null) { return propertyInfo.GetMethod.Invoke(obj, null); } return null; } public static object GetDefaultValue(this PropertyInfo property) { return property.PropertyType.IsValueType ? Activator.CreateInstance(property.PropertyType) : null; }}通過實例化參數，對屬性賦值，將對象作為參數傳入，反射獲取對象名稱，列名，列值。要求對象名與表名一致，屬性與列名一致，感謝大家對VeVb武林網的支持。
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