Entity Framework 6 Migration to change CLOB column to VARCHAR in Oracle

ef-migrations entity-framework entity-framework-6 oracle

Question

I am trying to change a CLOB column to VARCHAR(2000) in oracle using EF 6 migration. When EF scaffold the migration file, I have the following line of code in my Up() method: 

AlterColumn("MTA.PLAN_SHEETS", "PLANSHEET_NAME", c => c.String(maxLength: 2000, unicode: false));

When I run the migration I get this error

invalid modification of columns

I know that in Oracle we cannot change a Clob to Varchar directly:
How to change a dataype CLOB TO VARCHAR2(sql)

What is the best approach to change a Clob to Varchar in Entity Framework migration?

1
2
5/23/2017 11:53:07 AM

Fastest Entity Framework Extensions

Bulk Insert
Bulk Delete
Bulk Update
Bulk Merge

Popular Answer

There is the same problem in probably all RDBMSs. I always use a code similar to this and I think (I'm quite sure) that this is the only way to do it.

AddColumn("MTA.PLAN_SHEETS", "TMP_COLUMN", c => c.String(maxLength: 2000, unicode: false));
Sql(@"UPDATE MTA.PLAN_SHEETS SET TMP_COLUMN = PLANSHEET_NAME");
DropColumn("MTA.PLAN_SHEETS", "PLANSHEET_NAME");
RenameColumn("MTA.PLAN_SHEETS", "TMP_COLUMN", "PLANSHEET_NAME");
1
1/20/2017 8:41:41 PM

Related Questions

How to create Unique key for a varchar column for entity framework database?

I had watch youtube video tutorial teaching how to create unique key...http://www.youtube.com/watch?v=oqrsfatxTYE&list=PL08903FB7ACA1C2FB&index=9...In the video, he has created a unique key for Email(nvarchar) column, I could create it when I create database manually, but when I try create unique key for a database created with entity framework cod...
entity-framework sql sql-server unique
asked by Lai32290

Entity Framework mapping between ASP Identity user and other tables - change Id column

I have a standard ...Identity... user in my app......public class ApplicationUser : IdentityUser<int, ApplicationUserLogin, ApplicationUserRole, ApplicationUserClaim> {... ......Which has ...Id... as primary key. ...How can I change ...Id... to UserId?... I ask this because I have table that should be connected with ...AspNetUsers... table. And I d...
asp.net asp.net-identity c# entity-framework entity-framework-6
asked by 1110

Entity framework migration - add new column with a value for existing entries

I have an application with Entity Framework Code First....In a table, I have to add a column. So I added it in the model and created a Migration....But during the migration, I would like to update the existing entries and add a value for this new column. This value has to be taken from the database (a constant field in my "Configuration" table)....
c# ef-code-first ef-migrations entity-framework
asked by user3544117

Oracle ODP.Net With Entity Framework 6 - Entity framework database compatible provider could not be found

Just to complement, i've tried everything but in my case it was solved by setting the "...defaultConnectionFactory...", like this:...<entityFramework> <defaultConnectionFactory type="Oracle.ManagedDataAccess.EntityFramework.OracleConnectionFactory, Oracle.ManagedDataAccess.EntityFramework"> </defaultConnectionFactory> <providers> <provider invari...
.net ado.net-entity-data-model entity-framework odac oracle
asked by Fernando Meneses Gomes

Code First Migration - Entity Framework - unable to add column to the table

Because the field is required, you need to specify a default value. Edit your migration file, find the line adding your column, and specify what the default value should be:...public override void Up() { AddColumn("dbo.MyTable", "EmailSubject", c => c.String(nullable: false, defaultValue: "")); } ...For reference: ...Default value for Requ...
asp.net asp.net-mvc c# ef-migrations entity-framework
asked by Will Eddins

ADO.NET Entity Framework - Oracle with Entity Framework 6

I'm trying to add an ADO.NET Entity Data Model to my solution which uses an Oracle database (ODP.NET), but I get the following error:..."Your project references the latest version of Entity Framework; however, an Entity Framework database provider compatible with this version could not be found for your data connection. If you have already i...
asp.net-mvc entity-framework entity-framework-6 oracle
asked by dev0007

EF6 Oracle default value for a column in code first migration

I am trying to write a migration that sets ...Default Value... for a NUMBER column in my ...Oracle... database using ...EntityFramework 6.... Here is my first try that didn't set the default value:... public override void Up() { AddColumn("MTA.PLAN_SHEETS", "QUANTITY_CHANGED", c => c.Decimal(nullable: true, precision: 3, scale: 0, de...
ef-code-first ef-migrations entity-framework-6 oracle
asked by Ehsan

Updating entity framework model after changing the data type of column in database table

I am working with entity framework 6 with database 1st approach. I changed the datatype of my columns in the table and after updating my model I got the following error:...Error 1 Error 2019: Member Mapping specified is not valid. The type 'Edm.Int32[Nullable=False,DefaultValue=]' of member 'Warranty' in type 'pjModel.Bill' is not compatible...
entity-framework-6 mapping member sqldatatypes updatemodel
asked by Amit Kaushal

How would I add new boolean column with default value "false" without changing migration file?

I want to add a new property to an object in my EF model. The property is called "Deleted" and should have default value "false". All previous entries in the database need to be assigned this default value. I am using automatic migration, so changing the Up and Drop functions in the migration is not possible (that i know of, at least)....I have tri...
.net entity-framework-6 postgresql psql
asked by Sigfrid Stjärnholm

Using AutoMapper and Entity Framework to change what columns are fetched from a database table

We have a new requirement where we need to dynamically fetch a list of columns from a table. We have 141 columns in this table, but say we only want to return 2 or 3 of them, we just don't know which 3 until run-time....These columns are passed in as a ...List<string>..., with the hopes I could use reflection to access the property on the source ob...
automapper automapper-8 c# entity-framework-6 iqueryable
asked by bla9x

Fastest Entity Framework Extensions

Bulk Insert
Bulk Delete
Bulk Update
Bulk Merge
View more on Stack Overflow

Prime Library

Performance

Expression Evaluator

More Projects...

Related

Licensed under: CC-BY-SA with attribution
Not affiliated with Stack Overflow
Licensed under: CC-BY-SA with attribution
Not affiliated with Stack Overflow