Entity Framework - How to check if table exists?

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I'm using the Entity Framework with Code First approach. The base class DbContext has functions to create and delete the database as well as to check for its existence.

I want to check if a special table (entity) is existing or not. Is it possible with an framework implementation or do I need to write custom methods? If I need to write my own implementation, what would be the most generic approach to do that?

Thanks for any help.

If you need to check existence of the table you must call custom SQL code:

bool exists = context.Database
                     .SqlQuery<int?>(@"
                         SELECT 1 FROM sys.tables AS T
                         INNER JOIN sys.schemas AS S ON T.schema_id = S.schema_id
                         WHERE S.Name = 'SchemaName' AND T.Name = 'TableName'")
                     .SingleOrDefault() != null;

Table name is defined by default as the name of DbSet exposed on your derived context but the default name can be overriden either by fluent API's ToTable method or Table data annotation.

Doing this in the generic way is not something supposed in code first approach. That will require browsing metadata and manually explore to which table is the entity mapped - this can be pretty complex because entity can be mapped to multiple tables. Code first doesn't offer access to metadata. You must convert DbContext to ObjectContext and browse MetadataWorkspace.

Edit:

To convert DbContext to ObjectContext use this:

ObjectContext objContext = ((IObjectContextAdapter)dbContext).ObjectContext;

Entity Framework - How to check if table exists?, If you need to check existence of the table you must call custom SQL code: bool exists = context. Database . SqlQuery<int?>(@" SELECT 1 FROM sys. Check if Record Exists in Entity Framework [duplicate] Ask Question Asked 6 years, 3 months ago. Active 10 months ago. Viewed 87k times 19. 3. This question

I can't add comment to previous post. I'm using SQL Compact and I don't know schema of the table. I'm using this code to check for table It's pretty the same that in previous post but It works for any table.

    /// <summary>
    /// Check if data table is exist in application
    /// </summary>
    /// <typeparam name="T">Class of data table to check</typeparam>
    /// <param name="db">DB Object</param>
    public static bool CheckTableExists<T>(this ModelLocker db) where T : class
    {
        try
        {
            db.Set<T>().Count();
            return true;

        }
        catch (Exception)
        {
            return false;
        }
    }

[SOLVED], There is ExecuteSqlCommand . context.Database.ExecuteSqlCommand("") However, it's limited to returning an integer indicating how many� Check if a table exists within a database using LINQ asp.net-mvc c# entity-framework linq. (with entity framework) whether a table exists in the database (I can

An alternative method; it's not as efficient as Ladislav's, but it's not tied to SQL Server (edited to add Where clause to address performance issue):

bool CheckTableExists()
{
    try
    {
        context.YourTable.Where(s => s.<yourKeyField> = <impossible value>).Count();
        return true;
    }
    catch (Exception)
    {
        return false;
    }
}

Check if a table exists within a database using LINQ, A much better option would be to store the version differences as configuration. This could be stored in the database itself, a configuration file or� Do you want generic way to check if entity was loaded by context or generic way to query database if entity exists? For the former case use: public bool Exists<T>(T entity) where T: class { return this.Set<T>().Local.Any(e => e == entity); } For the latter case use (it will check loaded entities as well):

Assumption: SQL Server

Catching any old exception when querying the DbSet does not mean the table does not exist.

Querying a DbSet where the table does not exist will throw an EntityCommandExecutionException with an inner exception of type SqlException. That inner exception has an ErrorNumber property.

Error number 208 reads (source):

Invalid object name '%.*ls'.

model.IsNew is used for different purpose, to find if it is a insert or update and hasData is used for different purpose, to check entity exists in database. You can not combine them both here. Member 11838038 16-Oct-15 3:37am

I think following code is a little bit more understandable.

using(YourDbEntities db = new YourDbEntities()) 
{
  bool IsExists = db.Database
   .SqlQuery <int?> (@"
    SELECT COUNT(*) FROM INFORMATION_SCHEMA.TABLES 
    WHERE TABLE_NAME = '" + yourTableName + "'
    ")
    .FirstOrDefault() > 0;

    return IsExists;
}

Check if Record Exists in Entity Framework c# entity-framework. English (en) Could somebody please tell me how I check to see if a record exists, if it does

ASP.NET Forums / Data Access / ADO.NET, Entity Framework, LINQ to SQL, Check if a table column value exists in another table column using linq. Jan 29,

I am doing this to determine if the record does not exist in the database table: bool exists = db.table.Any(t => t.EntityID != list.EntityID) But can not seem to manage the reverse. The list and the database table have 1 to 1 mapping using Entity Framework. If record exists in database but not in list then delete.

How to check if an object exists in the database? What is the best way performance wise to check if the object exists in the database. StackOverflow Related Questions. Best way to check if object exists in Entity Framework? Answer. For IEnumerable, using Any() method is the fastest way to check if the object exists in the database. It only has

Comments
  • How can I convert DbContext to ObjectContext? I've seend diffrent approaches to check for the existence of a table. Is there any difference between your solutin an a) SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = 'TheSchema' AND TABLE_NAME = 'TheTable')) or b) SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[TableName]') AND type in (N'U')? Could you explain advantages/disadvantages? I would prefer to use a most standard conform way.
  • Generally all these SQL selects query the same information - that is just different way to get the same result.
  • What does type in (N'U') mean? Your version does ignore the table schema, right?
  • I modified query to work with schema as well. Here you have list of types: msdn.microsoft.com/en-us/library/ms190324.aspx U means user defined table.
  • This doesn't work for me (maybe due to MS changing SQL server?). All my S.Name are "dbo", so there are no results.
  • catching any random exception doesn't necessarily mean the table doesn't exist.
  • Also, using Any may improve the query in case it exists
  • Dont use exceptions for flow control, its an anti pattern
  • Agree Exceptions are used only for 'exceptions' not to normal operations.
  • The property is actually named Number.