.net 如何在 Linq 中执行 SQL Like %？
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How to do SQL Like % in Linq?
提问by Matt Dell
I have a procedure in SQL that I am trying to turn into Linq:
我在 SQL 中有一个过程，我试图将其转换为 Linq：
SELECT O.Id, O.Name as Organization
FROM Organizations O
JOIN OrganizationsHierarchy OH ON O.Id=OH.OrganizationsId
where OH.Hierarchy like '%/12/%'
The line I am most concerned with is:
我最关心的一行是：
where OH.Hierarchy like '%/12/%'
I have a column that stores the hierarchy like /1/3/12/ for example so I just use %/12/% to search for it.
例如，我有一列存储像 /1/3/12/ 这样的层次结构，所以我只使用 %/12/% 来搜索它。
My question is, what is the Linq or .NET equivalent to using the percent sign?
我的问题是，Linq 或 .NET 相当于使用百分号是什么？
回答by andleer
.Where(oh => oh.Hierarchy.Contains("/12/"))
You can also use .StartsWith()or .EndsWith().
您也可以使用.StartsWith()或.EndsWith()。
回答by L P
Use this:
用这个：
from c in dc.Organization
where SqlMethods.Like(c.Hierarchy, "%/12/%")
select *;
回答by KristoferA
I'm assuming you're using Linq-to-SQL* (see note below). If so, use string.Contains, string.StartsWith, and string.EndsWith to generate SQL that use the SQL LIKE operator.
我假设您使用的是 Linq-to-SQL*（请参阅下面的注释）。如果是，请使用 string.Contains、string.StartsWith 和 string.EndsWith 生成使用 SQL LIKE 运算符的 SQL。
from o in dc.Organization
join oh in dc.OrganizationsHierarchy on o.Id equals oh.OrganizationsId
where oh.Hierarchy.Contains(@"/12/")
select new { o.Id, o.Name }
or
或者
from o in dc.Organization
where o.OrganizationsHierarchy.Hierarchy.Contains(@"/12/")
select new { o.Id, o.Name }
Note:* = if you are using the ADO.Net Entity Framework (EF / L2E) in .net 3.5, be aware that it will not do the same translation as Linq-to-SQL. Although L2S does a proper translation, L2E v1 (3.5) will translate into a t-sql expression that will force a full table scan on the table you're querying unless there is another better discriminator in your where clause or join filters.
Update:This is fixed in EF/L2E v4 (.net 4.0), so it will generate a SQL LIKE just like L2S does.
注意：* = 如果您在 .net 3.5 中使用 ADO.Net 实体框架 (EF / L2E)，请注意它不会执行与 Linq-to-SQL 相同的转换。尽管 L2S 进行了适当的转换，但 L2E v1 (3.5) 将转换为 t-sql 表达式，该表达式将强制对您正在查询的表进行全表扫描，除非您的 where 子句或连接过滤器中有另一个更好的鉴别器。
更新：这在 EF/L2E v4 (.net 4.0) 中已修复，因此它会像 L2S 一样生成 SQL LIKE。
回答by robertz
If you are using VB.NET, then the answer would be "*". Here is what your where clause would look like...
如果您使用的是 VB.NET，那么答案将是“*”。这是您的 where 子句的样子...
Where OH.Hierarchy Like '*/12/*'
Note: "*" Matches zero or more characters. Here is the msdn article for the Like operator.
注意：“*”匹配零个或多个字符。这是 Like 运算符的 msdn 文章。
回答by Rumplin
Well indexOf works for me too
好吧 indexOf 也适用于我
var result = from c in SampleList
where c.LongName.IndexOf(SearchQuery) >= 0
select c;
回答by Ernesto
Use such code
使用这样的代码
try
{
using (DatosDataContext dtc = new DatosDataContext())
{
var query = from pe in dtc.Personal_Hgo
where SqlMethods.Like(pe.nombre, "%" + txtNombre.Text + "%")
select new
{
pe.numero
,
pe.nombre
};
dgvDatos.DataSource = query.ToList();
}
}
catch (Exception ex)
{
string mensaje = ex.Message;
}
回答by kofifus
.NET core now has EF.Functions.Like
.NET 核心现在有 EF.Functions.Like
回答by ComeIn
In case you are not matching numeric strings, always good to have common case:
如果您不匹配数字字符串，使用常见情况总是好的：
.Where(oh => oh.Hierarchy.ToUpper().Contains(mySearchString.ToUpper()))
回答by H. Pauwelyn
I do always this:
我总是这样做：
from h in OH
where h.Hierarchy.Contains("/12/")
select h
I know I don't use the like statement but it's work fine in the background is this translated into a query with a like statement.
我知道我不使用 like 语句，但它在后台工作正常，将其转换为带有 like 语句的查询。
回答by isuruAb
Try this, this works fine for me
试试这个，这对我来说很好用
from record in context.Organization where record.Hierarchy.Contains(12) select record;
