[英]Include where clause on linq query when param is not null Npgsql
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:
bool RegisterContact(Contact contactInfo) {
bool entityExists =
_dbContext.Contacts.FirstOrDefault(
p => (p.FilesID.Equals(contactInfo.FilesID))
&& (p.EmailAddress ==
(string.IsNullOrEmpty(
contactInfo.EmailAddress)
? p.EmailAddress
: contactInfo.EmailAddress))
&&
(p.DisplayName ==
(string.IsNullOrEmpty(
contactInfo.DisplayName)
? p.DisplayName
: contactInfo.DisplayName)));
}
此查询包括搜索条件中包含值(非空)的字段(FilesID,EmailAddress,DisplayName)
这种技术在MSSQL中运行良好,今天我将数据库管理器改为PostgreSQL并使用Npgsql。
所有的东西都工作,除了上面的linq查询,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:
bool RegisterContact(Contact contactInfo)
{
Contact entityExists = null;
if (string.IsNullOrEmpty(contactInfo.EmailAddress) &&
(string.IsNullOrEmpty(contactInfo.DisplayName)))
entityExists =
_dbContext.Contacts.FirstOrDefault(
p => p.FilesID.Equals(contactInfo.FilesID));
if (!string.IsNullOrEmpty(contactInfo.EmailAddress) && string.IsNullOrEmpty(contactInfo.DisplayName))
entityExists =
_dbContext.Contacts.FirstOrDefault(
p =>
p.FilesID.Equals(contactInfo.FilesID) &&
p.EmailAddress == contactInfo.EmailAddress);
if (string.IsNullOrEmpty(contactInfo.EmailAddress) && !string.IsNullOrEmpty(contactInfo.DisplayName))
entityExists =
_dbContext.Contacts.FirstOrDefault(
p =>
p.FilesID.Equals(contactInfo.FilesID) &&
p.DisplayName == contactInfo.DisplayName);
if (!string.IsNullOrEmpty(contactInfo.EmailAddress) &&
!string.IsNullOrEmpty(contactInfo.DisplayName))
entityExists =
_dbContext.Contacts.FirstOrDefault(
p =>
p.FilesID.Equals(contactInfo.FilesID) &&
p.EmailAddress == contactInfo.EmailAddress &&
p.DisplayName == contactInfo.DisplayName);
}
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?
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NULL。
- 不好
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.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。 我将向NpgSQL报告此案。
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