Question

我有以下方法在数据库中注册联系人，但在注册之前我检查联系人是否存在：

<asp:FormView ID="fvWebDescription" CssClass="webdescription" runat="server" DataKeyNames="id, type" 
                        DataSourceID="sdsWebVisitorsDescription">
                        <EditItemTemplate>
                            <custom:CustomEditor ID="txtDescription" runat="server" Content='<%# Bind("content") %>' />
                            <br />
                            <asp:LinkButton ID="UpdateButton" runat="server" CausesValidation="True" CommandName="Update" 
                                 Text="Update" /> | <asp:LinkButton ID="UpdateCancelButton" runat="server" 
                                CausesValidation="False" CommandName="Cancel" Text="Cancel" />
                        </EditItemTemplate>
                        <InsertItemTemplate>
                            <custom:CustomEditor ID="txtDescription" runat="server" Content='<%# Bind("content") %>' />
                            <br />
                            <asp:LinkButton ID="InsertButton" runat="server" CausesValidation="True" 
                                CommandName="Insert" Text="Insert" /> | <asp:LinkButton ID="InsertCancelButton" runat="server" 
                                CausesValidation="False" CommandName="Cancel" Text="Cancel" />
                        </InsertItemTemplate>
                        <ItemTemplate>
                            <asp:Label ID="contentLabel" runat="server" Text='<%# Bind("content") %>' />
                            <br />
                            <asp:LinkButton ID="EditButton" runat="server" CausesValidation="False" 
                                CommandName="Edit" Text="Edit" OnCommand="loadDescription" CommandArgument="web" />

                        </ItemTemplate>
                        <EmptyDataTemplate>This business does not have a description for website visitors. Please 
                            <asp:LinkButton ID="NewButton" runat="server" CausesValidation="False" 
                                CommandName="New" Text="click here" /> to add one.</EmptyDataTemplate>
                    </asp:FormView>

此查询包含搜索条件中包含值（非空）的字段（FilesID，EmailAddress，DisplayName）

这种技术在MSSQL中工作正常，今天我将数据库管理器改为PostgreSQL并使用Npgsql。

除了上面的linq查询之外，所有工作都有效，它引发了一个异常消息：“无法确定参数$ 2的数据类型”

我被迫以这种方式解决它：

 $(document).delegate(('.webdescription body'), "click", function () {
                            console.log(this).text();
                        });

这是Npgsql错误还是设计错误？该问题的任何已知解决方案/解决方法？

Answer 1

我目前有同样的情况。我认为问题是NpgSQL缺乏对string.IsNullOrEmpty的认可。

我用空字符串检查替换了测试，始终将输入参数识别为非空。

- 糟糕

        var data = from art in _ctx.Set<Soleo.Model.DLAR>()
                   from iva in _ctx.Set<Soleo.Model.DLAI>().Where(k => k.DITTA == art.DITTA && k.COD == art.CIVA).DefaultIfEmpty()
                   from fam in _ctx.Set<Soleo.Model.DLFA>().Where(k => k.DITTA == art.DITTA && k.COD == art.FAM).DefaultIfEmpty()
                   from mar in _ctx.Set<Soleo.Model.DLMA>().Where(k => k.DITTA == art.DITTA && k.COD == art.MAR).DefaultIfEmpty()
                   from udm in _ctx.Set<Soleo.Model.DLUM>().Where(k => k.DITTA == art.DITTA && k.COD == art.UM).DefaultIfEmpty()
                   where art.DITTA == DLAUTH.Config.Current.DITTA && art.COD.Contains(sel_cod) && art.DES.Contains(sel_des)
                   && (string.IsNullOrEmpty(sel_fam) || string.Compare(art.FAM, sel_fam, true) == 0)
                   && (string.IsNullOrEmpty(sel_mar) || string.Compare(art.MAR, sel_mar, true) == 0)
                   && (art.DIS >= sel_dis_da && art.DIS <= sel_dis_a)
                   select new
                   {
                       COD = art.COD,
                       DES = art.DES,
                       DES_UDM = udm.DES,
                       DES_MAR = mar.DES,
                       DES_FAM = fam.DES,
                       DES_CIVA = iva.DES,
                       MAG1 = art.MAG1,
                       MAG2 = art.MAG2,
                       DES_DIS = art.DIS == 1 ? "Si" : "No"
                   };

- 好：

            var data = from art in _ctx.Set<Soleo.Model.DLAR>()
                   from iva in _ctx.Set<Soleo.Model.DLAI>().Where(k => k.DITTA == art.DITTA && k.COD == art.CIVA).DefaultIfEmpty()
                   from fam in _ctx.Set<Soleo.Model.DLFA>().Where(k => k.DITTA == art.DITTA && k.COD == art.FAM).DefaultIfEmpty()
                   from mar in _ctx.Set<Soleo.Model.DLMA>().Where(k => k.DITTA == art.DITTA && k.COD == art.MAR).DefaultIfEmpty()
                   from udm in _ctx.Set<Soleo.Model.DLUM>().Where(k => k.DITTA == art.DITTA && k.COD == art.UM).DefaultIfEmpty()
                   where art.DITTA == DLAUTH.Config.Current.DITTA && art.COD.Contains(sel_cod) && art.DES.Contains(sel_des)
                   && (string.Compare(sel_fam, "", true) == 0 || string.Compare(art.FAM, sel_fam, true) == 0)
                   && (string.Compare(sel_mar, "", true) == 0 || string.Compare(art.MAR, sel_mar, true) == 0)
                   && (art.DIS >= sel_dis_da && art.DIS <= sel_dis_a)
                   select new
                   {
                       COD = art.COD,
                       DES = art.DES,
                       DES_UDM = udm.DES,
                       DES_MAR = mar.DES,
                       DES_FAM = fam.DES,
                       DES_CIVA = iva.DES,
                       MAG1 = art.MAG1,
                       MAG2 = art.MAG2,
                       DES_DIS = art.DIS == 1 ? "Si" : "No"
                   };

但我不认为这是解决方案。我将把案例报告给NpgSQL。

当param不为null Npgsql时，在linq查询中包含where子句

1 个答案: