コード例 #1
0
        /// <summary>
        /// Expression 转成 Where String
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="predicate"></param>
        /// <param name="databaseType">数据类型(用于字段是否加引号)</param>
        /// <returns></returns>
        public static string GetWhereByLambda <T>(Expression <Func <T, bool> > predicate, string databaseType)
        {
            try
            {
                bool withQuotationMarks = GetWithQuotationMarks(databaseType);

                ConditionBuilder conditionBuilder = new ConditionBuilder();
                conditionBuilder.SetIfWithQuotationMarks(withQuotationMarks); //字段是否加引号(PostGreSql,Oracle)
                conditionBuilder.SetDataBaseType(databaseType);
                conditionBuilder.Build(predicate);

                for (int i = 0; i < conditionBuilder.Arguments.Length; i++)
                {
                    object ce = conditionBuilder.Arguments[i];
                    if (ce == null)
                    {
                        conditionBuilder.Arguments[i] = DBNull.Value;
                    }
                    else if (ce is string || ce is char)
                    {
                        if (ce.ToString().ToLower().Trim().IndexOf(@"in(") == 0 ||
                            ce.ToString().ToLower().Trim().IndexOf(@"not in(") == 0 ||
                            ce.ToString().ToLower().Trim().IndexOf(@" like '") == 0 ||
                            ce.ToString().ToLower().Trim().IndexOf(@"not like") == 0)
                        {
                            conditionBuilder.Arguments[i] = string.Format(" {0} ", ce.ToString());
                        }
                        else
                        {
                            //****************************************
                            conditionBuilder.Arguments[i] = string.Format("'{0}'", ce.ToString());
                        }
                    }
                    else if (ce is DateTime)
                    {
                        conditionBuilder.Arguments[i] = string.Format("'{0}'", ce.ToString());
                    }
                    else if (ce is int || ce is long || ce is short || ce is decimal || ce is double || ce is float || ce is bool || ce is byte || ce is sbyte)
                    {
                        conditionBuilder.Arguments[i] = ce.ToString();
                    }
                    else if (ce is ValueType)
                    {
                        conditionBuilder.Arguments[i] = ce.ToString();
                    }
                    else
                    {
                        conditionBuilder.Arguments[i] = string.Format("'{0}'", ce.ToString());
                    }
                }
                string strWhere = string.Format(conditionBuilder.Condition, conditionBuilder.Arguments);
                return(strWhere);
            }
            catch {
                return(null);
            }
        }
コード例 #2
0
        /// <summary>
        /// Expression 转成 Where String
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="predicate"></param>
        /// <param name="databaseType">数据类型(用于字段是否加引号)</param>
        /// <returns></returns>
        public static string GetWhereByLambda <T>(Expression <Func <T, bool> > predicate, string databaseType)
        {
            try
            {
                bool withQuotationMarks = GetWithQuotationMarks(databaseType);

                ConditionBuilder conditionBuilder = new ConditionBuilder();
                conditionBuilder.SetIfWithQuotationMarks(withQuotationMarks); //字段是否加引号(PostGreSql,Oracle)
                conditionBuilder.SetDataBaseType(databaseType);
                conditionBuilder.Build(predicate);

                for (int i = 0; i < conditionBuilder.Arguments.Length; i++)
                {
                    object ce = conditionBuilder.Arguments[i];
                    if (ce == null)
                    {
                        conditionBuilder.Arguments[i] = "NULL";
                    }
                    else if (ce is string || ce is char)
                    {
                        if (ce.ToString().ToLower().Trim().IndexOf(@"in(") == 0 ||
                            ce.ToString().ToLower().Trim().IndexOf(@"not in(") == 0 ||
                            ce.ToString().ToLower().Trim().IndexOf(@" like '") == 0 ||
                            ce.ToString().ToLower().Trim().IndexOf(@"not like") == 0)
                        {
                            conditionBuilder.Arguments[i] = string.Format(" {0} ", ce.ToString());
                        }
                        else
                        {
                            //****************************************
                            conditionBuilder.Arguments[i] = string.Format("'{0}'", ce.ToString());
                        }
                    }
                    else if (ce is DateTime)
                    {
                        conditionBuilder.Arguments[i] = string.Format("'{0}'", ((DateTime)ce).ToString("yyyy-MM-dd HH:mm:ss")); //将日期格式化
                    }
                    else if (ce is bool)                                                                                        //布尔类型值,转换为1(True)、0(False)
                    {
                        conditionBuilder.Arguments[i] = ((bool)ce) ? 1 : 0;
                    }
                    else if (ce is int || ce is long || ce is short || ce is decimal || ce is double || ce is float || ce is byte || ce is sbyte)
                    {
                        conditionBuilder.Arguments[i] = ce.ToString();
                    }
                    else if (ce is ValueType)
                    {
                        conditionBuilder.Arguments[i] = ce.ToString();
                    }
                    else
                    {
                        conditionBuilder.Arguments[i] = string.Format("'{0}'", ce.ToString());
                    }
                }
                string strWhere = string.Format(conditionBuilder.Condition, conditionBuilder.Arguments);
                strWhere = strWhere.Replace("<> NULL", "IS NOT NULL");
                strWhere = strWhere.Replace("= NULL", "IS NULL");

                return(strWhere);
            }
            catch {
                return(null);
            }
        }