I want to change the database name in SqlMapConfig.xml file from the application, does any one help me?
You can override the database when you instantiate the Ibatis mapper instance; I do this for switching between debug and release builds of the application and hence accessing a different target database.
If your xml file is in an assembly called DatalayerAssembly for example, you might have a method for returning your new Ibatis instance based on a database name like this:
public IBatisNet.DataMapper.ISqlMapper CreateNewIbatis(
String serverName,
String databaseName)
{
// Load the config file (embedded resource in assembly).
System.Xml.XmlDocument xmlDoc = IBatisNet.Common.Utilities.Resources.GetEmbeddedResourceAsXmlDocument("SqlMapConfig.xml, DatalayerAssembly");
// Overwrite the connectionString in the XmlDocument, hence changing database.
// NB if your connection string needs extra parameters,
// such as `Integrated Security=SSPI;` for user authentication,
// then append that to InnerText too.
xmlDoc["sqlMapConfig"]["database"]["dataSource"]
.Attributes["connectionString"]
.InnerText = "Server=" + serverName + ";Database=" + databaseName;
// Instantiate Ibatis mapper using the XmlDocument via a Builder,
// instead of Ibatis using the config file.
IBatisNet.DataMapper.Configuration.DomSqlMapBuilder builder = new IBatisNet.DataMapper.Configuration.DomSqlMapBuilder();
IBatisNet.DataMapper.ISqlMapper ibatisInstance = builder.Configure(xmlDoc);
// Now use the ISqlMapper instance ("ibatisInstance") as normal.
return ibatisInstance;
}
I'm using this approach in Ibatis 1.6.2.0 on .Net but the exact SqlMap config file might vary depending by version. Either way the approach is the same; you just might need a different Xml path (i.e. the bit that reads ["sqlMapConfig"]["database"] etc may need changing for your config file)
Hope that helps.
Related
I want to know whether a particular database file exists in my codenameone app.
Here's the code I have:
if (CN.existsInFileSystem(Display.getInstance()
.getDatabasePath("my.db")))
overwriteDb = false;
It seems that the getDatabasePath method will create the database if it doesn't already exist, at least on the windows/eclipse simulator. (I haven't tried on any devices).
The javadocs say that getDatabasePath will return null when the database doesn't exist, however it returns the path of the newly created db file.
Is there a way to get the path without actually creating a zero byte file?
No it doesn't create the database, I just verified it in the code. The JavaDoc is incorrect and I fixed it for the next update. The code you have should work just fine.
This is the Android implementation of the method:
public String getDatabasePath(String databaseName) {
if (databaseName.startsWith("file://")) {
return databaseName;
}
File db = new File(getContext().getApplicationInfo().dataDir + "/databases/" + databaseName);
return db.getAbsolutePath();
}
You will notice null is never returned and nothing is created. The fixed docs look like this:
Returns the file path of the Database if support for database exists on the platform.
#param databaseName the name of the database with out / or path elements e.g. mydatabase.db
#return the file path of the database or null if database isn't supported
I have following C# code in a console application.
Whenever I debug the application and run the query1 (which inserts a new value into the database) and then run query2 (which displays all the entries in the database), I can see the new entry I inserted clearly. However, when I close the application and check the table in the database (in Visual Studio), it is gone. I have no idea why it is not saving.
using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Data.SqlServerCe;
using System.Data;
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
try
{
string fileName = "FlowerShop.sdf";
string fileLocation = "|DataDirectory|\\";
DatabaseAccess dbAccess = new DatabaseAccess();
dbAccess.Connect(fileName, fileLocation);
Console.WriteLine("Connected to the following database:\n"+fileLocation + fileName+"\n");
string query = "Insert into Products(Name, UnitPrice, UnitsInStock) values('NewItem', 500, 90)";
string res = dbAccess.ExecuteQuery(query);
Console.WriteLine(res);
string query2 = "Select * from Products";
string res2 = dbAccess.QueryData(query2);
Console.WriteLine(res2);
Console.ReadLine();
}
catch (Exception e)
{
Console.WriteLine(e);
Console.ReadLine();
}
}
}
class DatabaseAccess
{
private SqlCeConnection _connection;
public void Connect(string fileName, string fileLocation)
{
Connect(#"Data Source=" + fileLocation + fileName);
}
public void Connect(string connectionString)
{
_connection = new SqlCeConnection(connectionString);
}
public string QueryData(string query)
{
_connection.Open();
using (SqlCeDataAdapter da = new SqlCeDataAdapter(query, _connection))
using (DataSet ds = new DataSet("Data Set"))
{
da.Fill(ds);
_connection.Close();
return ds.Tables[0].ToReadableString(); // a extension method I created
}
}
public string ExecuteQuery(string query)
{
_connection.Open();
using (SqlCeCommand c = new SqlCeCommand(query, _connection))
{
int r = c.ExecuteNonQuery();
_connection.Close();
return r.ToString();
}
}
}
EDIT: Forgot to mention that I am using SQL Server Compact Edition 4 and VS2012 Express.
It is a quite common problem. You use the |DataDirectory| substitution string. This means that, while debugging your app in the Visual Studio environment, the database used by your application is located in the subfolder BIN\DEBUG folder (or x86 variant) of your project. And this works well as you don't have any kind of error connecting to the database and making update operations.
But then, you exit the debug session and you look at your database through the Visual Studio Server Explorer (or any other suitable tool). This window has a different connection string (probably pointing to the copy of your database in the project folder). You search your tables and you don't see the changes.
Then the problem get worse. You restart VS to go hunting for the bug in your app, but you have your database file listed between your project files and the property Copy to Output directory is set to Copy Always. At this point Visual Studio obliges and copies the original database file from the project folder to the output folder (BIN\DEBUG) and thus your previous changes are lost.
Now, your application inserts/updates again the target table, you again can't find any error in your code and restart the loop again until you decide to post or search on StackOverflow.
You could stop this problem by clicking on the database file listed in your Solution Explorer and changing the property Copy To Output Directory to Copy If Newer or Never Copy. Also you could update your connectionstring in the Server Explorer to look at the working copy of your database or create a second connection. The first one still points to the database in the project folder while the second one points to the database in the BIN\DEBUG folder. In this way you could keep the original database ready for deployment purposes and schema changes, while, with the second connection you could look at the effective results of your coding efforts.
EDIT Special warning for MS-Access database users. The simple act of looking at your table changes the modified date of your database ALSO if you don't write or change anything. So the flag Copy if Newer kicks in and the database file is copied to the output directory. With Access better use Copy Never.
Committing changes / saving changes across debug sessions is a familiar topic in SQL CE forums. It is something that trips up quite a few people. I'll post links to source articles below, but I wanted to paste the answer that seems to get the best results to the most people:
You have several options to change this behavior. If your sdf file is part of the content of your project, this will affect how data is persisted. Remember that when you debug, all output of your project (including the sdf) if in the bin/debug folder.
You can decide not to include the sdf file as part of your project and manage the file location runtime.
If you are using "copy if newer", and project changes you make to the database will overwrite any runtime/debug changes.
If you are using "Do not copy", you will have to specify the location in code (as two levels above where your program is running).
If you have "Copy always", any changes made during runtime will always be overwritten
Answer Source
Here is a link to some further discussion and how to documentation.
Our team's application development involves using Effort Testing Tool to mock our Entity Framework's DbContext. However, it seems that Effort Testing Tool needs to be see the actual SQL Server Database that the application uses in order to mock our Entity Framework's DbContext which seems to going against proper Unit Testing principles.
The reason being that in order to unit test our application code by mocking anything related to Database connectivity ( for example Entity Framework's DbContext), we should Never need a Database to be up and running.
How would I configure Effort Testing Tool to mock Entity Framework's DbContext withOut the actual SQL Server Database up and running?
*
Update:
#gert-arnold We are using Entity Framework Model First approach to implement the back-end model and database.
The following excerpt is from the test code:
connection = Effort.EntityConnectionFactory.CreateTransient("name=NorthwindModel");
jsAudtMppngPrvdr = new BlahBlahAuditMappingProvider();
fctry = new BlahBlahDataContext(jsAudtMppngPrvdr, connection, false);
qryCtxt = new BlahBlahDataContext(connection, false);
audtCtxt = new BlahBlahAuditContext(connection, false);
mockedReptryCtxt = new BlahBlahDataContext(connection, false);
_repository = fctry.CreateRepository<Account>(mockedReptryCtxt, null);
_repositoryAccountRoleMaps = fctry.CreateRepository<AccountRoleMap>(null, _repository);
The "name=NorthwindModel" pertains to our edmx file which contains information about our Database tables
and their corresponding relationships.
If I remove the "name=NorthwindModel" by making the connection like the following line of code, I get an error stating that it expects an argument:
connection = Effort.EntityConnectionFactory.CreateTransient(); // throws error
Could you please explain how the aforementioned code should be rewritten?
You only need that connection string because Effort needs to know where the EDMX file is.
The EDMX file contains all information required for creating an inmemory store with an identical schema you have in your database. You have to specify a connection string only because I thought it would be convenient if the user didn't have to mess with EDMX paths.
If you check the implementation of the CreateTransient method you will see that it merely uses the connection string to get the metadata part of it.
public static EntityConnection CreateTransient(string entityConnectionString, IDataLoader dataLoader)
{
var metadata = GetEffortCompatibleMetadataWorkspace(ref entityConnectionString);
var connection = DbConnectionFactory.CreateTransient(dataLoader);
return CreateEntityConnection(metadata, connection);
}
private static MetadataWorkspace GetEffortCompatibleMetadataWorkspace(ref string entityConnectionString)
{
entityConnectionString = GetFullEntityConnectionString(entityConnectionString);
var connectionStringBuilder = new EntityConnectionStringBuilder(entityConnectionString);
return MetadataWorkspaceStore.GetMetadataWorkspace(
connectionStringBuilder.Metadata,
metadata => MetadataWorkspaceHelper.Rewrite(
metadata,
EffortProviderConfiguration.ProviderInvariantName,
EffortProviderManifestTokens.Version1));
}
I have a WinForms project, which consists of 10 forms. Forms are called to each other, each shape is drawn to the database
(I'm using LINQ to SQL) how best to create a database connection, I set up the connection when loading the main form
string path = "Data Source = | DataDirectory | \ \ Database.sdf";
Database db = new Database (path);
and then loading each window is transmitted through an object constructor db, then work with the database,
Window1 win1 = new Window1(db)
there may be a better way?
Try to use static class for your db operations.
Well for one, you should abstract your database logic / connections into their own class or assembly. The connection string shouldn't be hard coded, but come from the app.config file.
I don't think you should be passing around the connection object.
As I stated above, abstract our your database code and wrap your the context in a Using statement.
I've searched the stackoverflow for a long time and didn't find a solution fit my situation, so I asked here.
I have a single asp.net website, and need the web app to access different SQL Server database by the subdomain name.
According to the url request subdomian to determine the access the different database.
prj1.test.com prj1--->use the prj1_DB
prj2.test.com prj2 use the prj2_DB
I couldn't find a better practice to solve the issue.
My intuition solution:
when the url request coming, get the url subdomain, get the subdomain's db connection string stored in the main db, passing the connection string to the DAL to get the data.
Index.aspx.cs
DataTable dt = ProjectObject.GetProjectIndexNotice(new object[] { 0, CurrentProject.DbConnectionString });
ProjectObject.cs
public static DataTable GetProjectIndexNotice(object[] param)
{
ProjectDLC obj = new ProjectDLC();
return obj.GetProjectIndexNotice(param);
}
ProjectDAL.cs
public DataTable GetProjectIndexNotice(object[] param)
{
return base.GetDataTableFromDatabase(param, "NEMP_GetProjectIndexNotice");
}
DALBase.cs
DataBase db = new Microsoft.Practices.EnterpriseLibrary.Data.Sql.SqlDatabase(CurrentProject.DbConnectionString);
I want to find a better way to solve this problem.
The solution I using above is:
get the dbConnectionString from main DB,
passing it over the Index.page ->BusinessObject Layer -->DAL Layer
It's so bad that passing the DB connection string from UI page to the DAL layer.
Any ideas?
Update 1:
What I really want is: don't pass the db connection string from UI to DAL layer.
I want to find a solution that don't do pass the db connstr from UI to DAL linearly.
Is there some pattern in asp.net to share some variable for UI layer and DAL Layer?
Update 2:
if I stored the project db info in a xml file or in the main db, it looks like this
it's a key-value part for the project. here is the question, I get the values all in the main DB or a xml file. How I get the key when I need to access the DB in DAL layer?
in the DAL layer, how to get the correct key for the currnet url request?
it's back to the above, pass the key from UI to DAL. that's I want to avoid.
the real problem is, I can get the key from url request in the UI layer, and I can get the value for that key in the DAL layer. but there is a gap between the two layers, How to conquer this gap?
If you can compute your connection string from a base connection string, then you could do something like this:
store the base connection string in your web.config
<connectionStrings>
<add name="BaseConnString"
connectionString="server=MyServer;database=master;Integrated Security=SSPI;" />
</connectionStrings>
load the base connection string into a SqlConnectionStringBuilder in your code:
string baseConnStr = WebConfigurationManager.ConnectionString["BaseConnString"].ConnectionString;
SqlConnectionStringBuilder scsBuilder =
new SqlConnectionStringBuilder(baseConnStr);
now, just define the database you want to connect to, e.g. based on something in your URL
scsBuilder.InitialCatalog = "ProjectDatabase" + ........ ;
use the resulting complete connection string for your SqlConnection:
using(SqlConnection _con = new SqlConnection(scsBuilder.ConnectionString))
{
// do something
}
Check out the MSDN docs on SqlConnectionStringBuilder.
With this approach, you'd store a single "base" connection string in your web.config and this wouldn't be changing, and using SqlConnectionStringBuilder, you can safely and efficiently define and "compute" your real, "dynamic" connection strings at runtime.
How about adding add the connection strings in web.config as:
Subdomain_connectionString
Now read the subdomain from Request:
Reading connection string from web.config in your DL:
ConfigurationManager.ConnectionStrings[Subdomain_connectionString].ConnectionString
Update:
You can also use xml files to store connection string values:
<ROOT>
<Project_1>
<IPAddress></IPAddress>
<DBName></DBName>
...
</Project_1>
<Project_2>
....
</ROOT>
Anytime a new project is added/removed this xml file would be updated. Use XPath expressions to parse the xml file.
#Passing Connection string from UI to DAL: Just try to add the System.web namespace to DAL layer. This would give access to Request object in DAL. Now you can get the subdomain and build the connectionstring in DAL itself. Not sure whether this is a right approach, but might work in your case.