Fill table in Entity Framework Migration
-
21-12-2019 - |
Question
One of my EF migrations creates a table and as part of the migration Up
method I would like to fill this table with initial data.
Here's my migration class:
public partial class Objects : DbMigration
{
void Fill(string table, string path, string fieldTerminator = ",", string rowTerminator = @"\n")
{
Sql(string.Format("BULK INSERT {0} FROM '{1}' WITH (FIELDTERMINATOR = '{2}', ROWTERMINATOR = '{3}')", table, path, fieldTerminator, rowTerminator));
}
public override void Up()
{
CreateTable(
"dbo.Objects",
c => new
{
ObjectId = c.Int(nullable: false),
Name = c.String(),
Location_X = c.Double(nullable: false),
Location_Y = c.Double(nullable: false),
Location_Z = c.Double(nullable: false),
})
.PrimaryKey(t => t.ObjectId);
Fill("dbo.Objects", @"C:\temp\Scratch\Junk\ConsoleApplication3\data\objects.csv");
}
public override void Down()
{
DropTable("dbo.Objects");
}
}
This works correctly on my machine from the Package Manager Console. However I would like to use a relative path for the file so that the entire development team can use this easily.
When I simply wrote the file name the update failed. When I tried concatenating the current directory to the file name I saw that the current directory was c:\windows\system32.
How can I make the update run from the project or solution directory?
Alternatively, is there a better way to fill the table during an update? I don't want to use the Seed
method becasue it doesn't do exactly what I want. For instance, there's only a single Seed
method while I want to write different code for different migrations.
Solution
As a workaround you may get path to the current source file and then to enter to relative path of the CSV file with data.
Meaning instead of:
dataFile = @"C:\temp\Scratch\Junk\ConsoleApplication3\data\objects.csv";
Have something like:
currentFile = GetSourceFilePath(); // See below hints for implementation
dataFile = Path.Combine(
Path.GetDirectoryName(currentFile),
@"..\data\objects.csv"
);
Here are some examples of how exactly to get access to source file path - Print the source filename and linenumber in C#.