Default convention for entity framework code first
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This document lists default code first conventions used by Entity Framework (EF) to map .NET entity classes to database tables and columns. It describes conventions for schema, table and column names, primary keys, foreign keys, data types, nullability, and column ordering. Properties will map to columns by default, and cascade deletes are enabled for relationships.
![table lists default code first conventions
Default
Convention For
Description
Schema By default, EF creates all the DB objects into the dbo schema.
Table Name <Entity Class Name> + 's'
EF will create a DB table with the entity class name suffixed by 's' e.g. Student domain class (entity) would
map to the Students table.
Primary key
Name
1) Id
2) <Entity Class Name> + "Id" (case insensitive)
EF will create a primary key column for the property named Id or <Entity Class Name> + "Id" (case
insensitive).
Foreign key
property Name
By default, EF will look for the foreign key property with the same name as the principal entity primary key
name.
If the foreign key property does not exist, then EF will create an FK column in the Db table with <Dependent
Navigation Property Name> + "_" + <Principal Entity Primary Key Property Name>
e.g. EF will create Grade_GradeId foreign key column in the Students table if the Student entity does not
contain foreignkey property for Grade.
Null column EF creates a null column for all reference type properties and nullable primitive properties e.g. string,
Nullable<int>, Student, Grade (all class type properties)
Not Null Column EF creates NotNull columns for Primary Key properties and non-nullable value type properties e.g. int, float,
decimal, datetime etc.
DB Columns
order
EF will create DB columns in the same order like the properties in an entity class. However, primary key
columns would be moved first.
Properties
mapping to DB
By default, all properties will map to the database. Use the [NotMapped] attribute to exclude property or
class from DB mapping.
Cascade delete Enabled by default for all types of relationships.](https://image.slidesharecdn.com/defaultconventionforentityframeworkcodefirst-180628033927/85/Default-convention-for-entity-framework-code-first-1-320.jpg)
![The following table list C# data type mapped with SQL Server data type.
C# Data Type Mapping to SQL Server Data Type
int int
string nvarchar(Max)
decimal decimal(18,2)
float real
byte[] varbinary(Max)
datetime datetime
bool bit
byte tinyint
short smallint
long bigint
double float
char No mapping
sbyte No mapping
(throws exception)
object No mapping](https://image.slidesharecdn.com/defaultconventionforentityframeworkcodefirst-180628033927/85/Default-convention-for-entity-framework-code-first-2-320.jpg)
Default convention for entity framework code first
- 1. table lists default code first conventions Default Convention For Description Schema By default, EF creates all the DB objects into the dbo schema. Table Name <Entity Class Name> + 's' EF will create a DB table with the entity class name suffixed by 's' e.g. Student domain class (entity) would map to the Students table. Primary key Name 1) Id 2) <Entity Class Name> + "Id" (case insensitive) EF will create a primary key column for the property named Id or <Entity Class Name> + "Id" (case insensitive). Foreign key property Name By default, EF will look for the foreign key property with the same name as the principal entity primary key name. If the foreign key property does not exist, then EF will create an FK column in the Db table with <Dependent Navigation Property Name> + "_" + <Principal Entity Primary Key Property Name> e.g. EF will create Grade_GradeId foreign key column in the Students table if the Student entity does not contain foreignkey property for Grade. Null column EF creates a null column for all reference type properties and nullable primitive properties e.g. string, Nullable<int>, Student, Grade (all class type properties) Not Null Column EF creates NotNull columns for Primary Key properties and non-nullable value type properties e.g. int, float, decimal, datetime etc. DB Columns order EF will create DB columns in the same order like the properties in an entity class. However, primary key columns would be moved first. Properties mapping to DB By default, all properties will map to the database. Use the [NotMapped] attribute to exclude property or class from DB mapping. Cascade delete Enabled by default for all types of relationships.
- 2. The following table list C# data type mapped with SQL Server data type. C# Data Type Mapping to SQL Server Data Type int int string nvarchar(Max) decimal decimal(18,2) float real byte[] varbinary(Max) datetime datetime bool bit byte tinyint short smallint long bigint double float char No mapping sbyte No mapping (throws exception) object No mapping