.net SQLite EF6在运行时以编程方式设置连接字符串
我尝试将表单EF3.5迁移到6(使用SQLite作为数据库)。我们无法在app config文件中设置连接字符串(这在ef6中没有问题)。我们必须在运行时以编程方式设置连接字符串(在用户选择SQLite文件之后) 这是我们的app.config.net SQLite EF6在运行时以编程方式设置连接字符串,.net,sqlite,runtime,entity-framework-6,connection-string,.net,Sqlite,Runtime,Entity Framework 6,Connection String,我尝试将表单EF3.5迁移到6(使用SQLite作为数据库)。我们无法在app config文件中设置连接字符串(这在ef6中没有问题)。我们必须在运行时以编程方式设置连接字符串(在用户选择SQLite文件之后) 这是我们的app.config <?xml version="1.0" encoding="utf-8"?> <configuration> <configSections> <!-- For more information on
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<configSections>
<!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
<section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
</configSections>
<connectionStrings>
<add name="testContext" connectionString="data source=Data\testdb.sqlite;Foreign Keys=True"
providerName="System.Data.SQLite" />
</connectionStrings>
<entityFramework>
<defaultConnectionFactory type="System.Data.Entity.Infrastructure.LocalDbConnectionFactory, EntityFramework">
<parameters>
<parameter value="v11.0" />
</parameters>
</defaultConnectionFactory>
<providers>
<provider invariantName="System.Data.SQLite" type="System.Data.SQLite.EF6.SQLiteProviderServices, System.Data.SQLite.EF6" />
</providers>
</entityFramework>
<system.data>
<DbProviderFactories>
<remove invariant="System.Data.SQLite" />
<remove invariant="System.Data.SQLite.EF6" />
<add name="System.Data.SQLite" invariant="System.Data.SQLite" description=".Net Framework Data Provider for SQLite (Entity Framework 6)" type="System.Data.SQLite.EF6.SQLiteProviderFactory, System.Data.SQLite.EF6" />
</DbProviderFactories>
</system.data>
</configuration>
如果使用app.config中的连接名称连接,则所有连接都可以正常工作。如果我尝试用第二个构造函数传递连接字符串,则会失败
这里有一个小例子
SQLiteConnectionStringBuilder builder =
factory.CreateConnectionStringBuilder() as SQLiteConnectionStringBuilder;
builder.DataSource = dataSource; // Path to file name of the user
builder.ForeignKeys = true;
var context = new FirmwareContext(builder.ToString());
var context = new FirmwareContext(builder.ToString());
var test = context.Firmware.FirstOrDefault();
我得到了以下异常(“Schlüsselwort wird nicht unterstützt:“外键”。”=>不支持键“外键”。如果删除外键集,则会出现以下异常(“提供程序未返回ProviderManifestToken字符串”)和一些内部异常
bas(connectionString)似乎为SQLite构建了MSSQL连接字符串和
如何使我的第二个构造函数与sqlite兼容?我也遇到了同样的问题。我找到了一个解决方法,使用了与基本DbContext类不同的构造函数:
public DbContext(DbConnection existingConnection, bool contextOwnsConnection);
使用此覆盖,您可以传递一个SQLiteConnection,而不是设置连接字符串的连接。例如,您可以向FirmwareContext添加一个新的构造函数
public FirmwareContext(string connectionString)
: base(new SQLiteConnection() { ConnectionString = connectionString }, true)
{
}
甚至
public FirmwareContext(string filename)
: base(new SQLiteConnection() { ConnectionString =
new SQLiteConnectionStringBuilder()
{ DataSource = filename, ForeignKeys = true }
.ConnectionString }, true)
{
}
进一步研究之后,问题似乎是没有为SQLite定义IDbConnectionFactory。因此,另一种方法是定义自己的工厂实现
public class SQLiteConnectionFactory : IDbConnectionFactory
{
public DbConnection CreateConnection(string connectionString)
{
return new SQLiteConnection(connectionString);
}
}
然后将“app.config”中的defaultConnectionFactory
条目替换为如下内容:
<defaultConnectionFactory type="MyDAL.SQLiteConnectionFactory, MyDAL" />
通常配置中的连接字符串如下所示
<add name="MuthootOneClientEntities" connectionString="metadata=res://*/LocalData.MuthootClientContext.csdl|res://*/LocalData.MuthootClientContext.ssdl|res://*/LocalData.MuthootClientContext.msl;provider=System.Data.SQLite;provider connection string="data source=D:\LocalRepo\trunk\dev\Muthoot.MuthootOne.API\src\Muthoot.MuthootOne.API.Services\LocalData\FD1CBA65-1B68-449F-8E6D-A652137466D4.db"" providerName="System.Data.EntityClient" />
太棒了。非常感谢。天哪,非常感谢。过了一会儿,我注意到使用了普通的SqlConnectionFactory,但我没有考虑创建自己的,因为它是一个基本组件。。。
<add name="MuthootOneClientEntities" connectionString="metadata=res://*/LocalData.MuthootClientContext.csdl|res://*/LocalData.MuthootClientContext.ssdl|res://*/LocalData.MuthootClientContext.msl;provider=System.Data.SQLite;provider connection string="data source=D:\LocalRepo\trunk\dev\Muthoot.MuthootOne.API\src\Muthoot.MuthootOne.API.Services\LocalData\FD1CBA65-1B68-449F-8E6D-A652137466D4.db"" providerName="System.Data.EntityClient" />
public partial class MuthootClientEntities : DbContext
{
public MuthootClientEntities()
: base(@"metadata=res://*/LocalData.MuthootClientContext.csdl|res://*/LocalData.MuthootClientContext.ssdl|res://*/LocalData.MuthootClientContext.msl;provider=System.Data.SQLite;provider connection string=""data source=" + System.Environment.CurrentDirectory + @"\LocalData\FD1CBA65-1B68-449F-8E6D-A652137466D4.db""")
{
var test = System.Environment.CurrentDirectory;
}