entity-framework

问题 I have a problem with booleans returned by an entity framework provider I'm writing. The EF expecting a boolean while the ADO provider returns an Int16 so the EF raises an InvalidOperationException The specified cast from a materialized 'System.Int16' type to the 'System.Boolean' type is not valid. Is there a way to customize the materialization process of the entity framework to make it call a materialization process implemented by the provider? EDIT Partially found a solution... I can't

问题 I started to get this error after marking an ID column on an entity with DatabaseGeneratedOption.Identity (for some reason EF didn't know it was an identity column and was trying to insert a value on that column). I found this question: A dependent property in a ReferentialConstraint is mapped to a store-generated column. However, as far as I can tell, all of my relations are perfectly fine. I checked every single table, and triple checked the tables related to the one on which I added the

问题 I started to get this error after marking an ID column on an entity with DatabaseGeneratedOption.Identity (for some reason EF didn't know it was an identity column and was trying to insert a value on that column). I found this question: A dependent property in a ReferentialConstraint is mapped to a store-generated column. However, as far as I can tell, all of my relations are perfectly fine. I checked every single table, and triple checked the tables related to the one on which I added the

问题 I have an enum public enum Group { Services = 1, Dev = 2, Support = 3 } I am using it in a model public class Invoice { public int ID { get; set; } public DateTime MyDate { get; set; } public string Name { get; set; } public Group? Group { get; set; } } Now I am calling a stored procedure using the above model class: public ... method(Group grp) var Details = this.Context.Database.SqlQuery<Invoice>("spname @ID,@MyDate,@Name,@Group, ...... new SqlParameter("Group", grp), ).ToList(); Group is

问题 I have the following class hirarchy: public class A { public string A_string; public int A_int; public double A_double; public B BInstance; } public class B { public string B_string; public int B_int; public double B_double; public C CInstance; } public class C { public string C_string; public int C_int; public double C_double; } and need a mapping to the following database values: +--------------+-----------+--------------+---------------------+-------------------+----------------------+----

问题 I have the following class hirarchy: public class A { public string A_string; public int A_int; public double A_double; public B BInstance; } public class B { public string B_string; public int B_int; public double B_double; public C CInstance; } public class C { public string C_string; public int C_int; public double C_double; } and need a mapping to the following database values: +--------------+-----------+--------------+---------------------+-------------------+----------------------+----

问题 Forward warning #0: upgrading to EF core is not an option in the near future. Forward warning #1: I can't change the column type to bit because this could potentially break legacy VB apps that employ the very same db I'm developing a new app for. Forward warning #2: I also can't employ the int property ==> hidden bool property approach because the very same model needs to work when targeting an Oracle database (in Oracle decimal(1,0) does indeed get mapped to bool without issues - I need to

问题 Forward warning #0: upgrading to EF core is not an option in the near future. Forward warning #1: I can't change the column type to bit because this could potentially break legacy VB apps that employ the very same db I'm developing a new app for. Forward warning #2: I also can't employ the int property ==> hidden bool property approach because the very same model needs to work when targeting an Oracle database (in Oracle decimal(1,0) does indeed get mapped to bool without issues - I need to

问题 May be, it is not so problematic for you. but i'm trying first time with json serialization. and also read other articles in stackowerflow. I have created Entity Framework data model. then by method get all data from object: private uqsEntities _db = new uqsEntities(); //get all data from table sysMainTableColumns where tableName=paramtableName public List<sysMainTableColumns> getDataAboutMainTable(string tableName) { return (from column in _db.sysMainTableColumns where column.TableName=

问题 May be, it is not so problematic for you. but i'm trying first time with json serialization. and also read other articles in stackowerflow. I have created Entity Framework data model. then by method get all data from object: private uqsEntities _db = new uqsEntities(); //get all data from table sysMainTableColumns where tableName=paramtableName public List<sysMainTableColumns> getDataAboutMainTable(string tableName) { return (from column in _db.sysMainTableColumns where column.TableName=