小编Moo*_*ozz的帖子

背景

我有一个只包含一列的表:名称.比方说,它只有四行

| Name      |
| test1.com |
| test2.com |
| test3.com |
| test4.com |

问题

如果我查询

var email = "a@test2.com";
Table.Where(x => email.EndsWith(x.Name));

我会得到一个空列表.但如果我先查询所有行并计算内存中的这样

var email = "a@test2.com";
Table.ToList().Where(x => email.EndsWith(x.Name));

我会得到一个只包含test2.com的列表,这是正确的.

为第一个查询生成的SQL是

SELECT "Extent1"."Name" AS "Name"
FROM "USER"."Table" "Extent1"
WHERE (( NVL(INSTR(REVERSE(:p__linq__0), REVERSE("Extent1"."Name")), 0) ) = 1)

我尝试用'a@test2.com'替换:p__linq__0并在SQLDeveloper中运行查询,结果是正确的.

更多信息

如果我将EndsWith()更改为Contains(),问题就会消失.这是为Contains()生成的SQL

SELECT "Extent1"."Name" AS "Name"
FROM "USER"."Table" "Extent1"
WHERE (( NVL(INSTR(:p__linq__0, "Extent1"."Name"), 0) ) > 0)

你知道EndsWith或REVERSE方法有什么问题吗？

环境

• EF5.0
• .NET4.5
• Oracle11g中
• ODP.NET11.2第3版

我想从一个视图查询数据,这是一个包含583,000条记录的表的视图.所以我写了一个简单的查询来从这个视图中查询

var uuid = "AB1-23456";
dbSet.SingleOrDefault(x => x.UserKey == uuid);

这是生成的sql

SELECT "Extent1"."UserKey" AS "UserKey", 
       CAST("Extent1"."IsDeleted" AS number(3,0)) AS "C1", 
       "Extent1"."FirstName" AS "FirstName", 
       "Extent1"."LastName" AS "LastName", 
       "Extent1"."UserLogin" AS "UserLogin", 
       "Extent1"."AccLocationKey" AS "AccLocationKey", 
       "Extent1"."CompanyKey" AS "CompanyKey"
FROM "UsersView" "Extent1"
WHERE ('AB1-23456' = "Extent1"."UserKey")

我运行了5次查询.第一次调用花了我350ms,下次调用平均花了我150ms这个查询太慢了,所以我把查询更改为这样

var queryString = 
    "SELECT \"Extent1\".\"UserKey\" AS \"UserKey\", " +
            "CAST( \"Extent1\".\"IsDeleted\" AS number(3,0)) AS \"IsDeleted\", " +
            "\"Extent1\".\"FirstName\" AS \"FirstName\", " +
            "\"Extent1\".\"LastName\" AS \"LastName\", " +
            "\"Extent1\".\"UserLogin\" AS \"UserLogin\", " +
            "\"Extent1\".\"AccLocationKey\" …

问题

我有这样一张桌子:

MyModel
MyShortField Number(1,0)
MyBoolField Number(1,0)

我想MyBoolField只存储0和1,但我想MyShortField存储1-9.所以,在EDMX,我定MyBoolField要Boolean和MyShortField到Int16

我配置这样的映射

<oracle.manageddataaccess.client>
  <version number="*">
    <edmMappings>
      <edmNumberMapping>
        <add NETType="bool" MinPrecision="1" MaxPrecision="1" DBType="Number"/>
        <add NETType="int16" MinPrecision="1" MaxPrecision="5" DBType="Number"/>
      </edmNumberMapping>
    </edmMappings>
  </version>
</oracle.manageddataaccess.client>

它没用.好像我的bool映射被覆盖了int16.有运行时异常

Models.MyTestApp.msl(21,12):错误2019:指定的成员映射无效.类型'Model.MyModel'中成员'MyBoolField'的类型'Edm.Boolean [Nullable = True,DefaultValue =]'与'OracleEFProvider.number不兼容[Nullable = True,DefaultValue =,Precision = 1,Scale = 0 ''成员'MyBoolField'在'Model.Store.MyModel'类型中.

我尝试交换这两行

<add NETType="int16" MinPrecision="1" MaxPrecision="5" DBType="Number"/>
<add NETType="bool" MinPrecision="1" MaxPrecision="1" DBType="Number"/>

这一次,上面的错误消失了,但是出现了新的错误.

Models.MyTestApp.msl(42,12):错误2019:指定的成员映射无效.类型'Model.MyModel'中成员'MyShortField'的类型'Edm.Int16 [Nullable = True,DefaultValue =]'与'OracleEFProvider.number不兼容[Nullable = True,DefaultValue =,Precision = 1,Scale = …