DbExpressionBuilder.CreateRef Method
Creates a new DbRefExpression that encodes a reference to a specific entity based on key values.
Assembly: EntityFramework (in EntityFramework.dll)
Name | Description | |
---|---|---|
![]() ![]() | CreateRef(EntitySet, DbExpression[]) | Creates a new DbRefExpression that encodes a reference to a specific entity based on key values. |
![]() ![]() | CreateRef(EntitySet, EntityType, DbExpression[]) | Creates a new DbRefExpression that encodes a reference to a specific entity of a given type based on key values. |
![]() ![]() | CreateRef(EntitySet, EntityType, IEnumerable<DbExpression>) | Creates a new DbRefExpression that encodes a reference to a specific entity of a given type based on key values. |
![]() ![]() | CreateRef(EntitySet, IEnumerable<DbExpression>) | Creates a new DbRefExpression that encodes a reference to a specific entity based on key values. |
DbExpressionBuilder.CreateRef Method (EntitySet, DbExpression[])
Creates a new DbRefExpression that encodes a reference to a specific entity based on key values.
public static DbRefExpression CreateRef( this EntitySet entitySet, params DbExpression[] keyValues )
Parameters
- entitySet
-
Type:
System.Data.Entity.Core.Metadata.Edm.EntitySet
The entity set in which the referenced element resides.
- keyValues
-
Type:
System.Data.Entity.Core.Common.CommandTrees.DbExpression[]
A collection of DbExpression s that provide the key values. These expressions must match (in number, type, and order) the key properties of the referenced entity type.
Return Value
Type: System.Data.Entity.Core.Common.CommandTrees.DbRefExpressionA new DbRefExpression that references the element with the specified key values in the given entity set.
Exception | Condition |
---|---|
ArgumentNullException | entitySet is null, or keyValues is null or contains null. |
ArgumentException | The count of keyValues does not match the count of key members declared by the entitySet’s element type, or keyValues contains an expression with a result type that is not compatible with the type of the corresponding key member. |
DbExpressionBuilder.CreateRef Method (EntitySet, EntityType, DbExpression[])
Creates a new DbRefExpression that encodes a reference to a specific entity of a given type based on key values.
public static DbRefExpression CreateRef( this EntitySet entitySet, EntityType entityType, params DbExpression[] keyValues )
Parameters
- entitySet
-
Type:
System.Data.Entity.Core.Metadata.Edm.EntitySet
The entity set in which the referenced element resides.
- entityType
-
Type:
System.Data.Entity.Core.Metadata.Edm.EntityType
The specific type of the referenced entity. This must be an entity type from the same hierarchy as the entity set's element type.
- keyValues
-
Type:
System.Data.Entity.Core.Common.CommandTrees.DbExpression[]
A collection of DbExpression s that provide the key values. These expressions must match (in number, type, and order) the key properties of the referenced entity type.
Return Value
Type: System.Data.Entity.Core.Common.CommandTrees.DbRefExpressionA new DbRefExpression that references the element with the specified key values in the given entity set.
Exception | Condition |
---|---|
ArgumentNullException | entitySet or entityType is null, or keyValues is null or contains null. |
ArgumentException | entityType is not from the same type hierarchy (a subtype, supertype, or the same type) as entitySet’s element type. |
ArgumentException | The count of keyValues does not match the count of key members declared by the entitySet’s element type, or keyValues contains an expression with a result type that is not compatible with the type of the corresponding key member. |
DbExpressionBuilder.CreateRef Method (EntitySet, EntityType, IEnumerable<DbExpression>)
Creates a new DbRefExpression that encodes a reference to a specific entity of a given type based on key values.
public static DbRefExpression CreateRef( this EntitySet entitySet, EntityType entityType, IEnumerable<DbExpression> keyValues )
Parameters
- entitySet
-
Type:
System.Data.Entity.Core.Metadata.Edm.EntitySet
The entity set in which the referenced element resides.
- entityType
-
Type:
System.Data.Entity.Core.Metadata.Edm.EntityType
The specific type of the referenced entity. This must be an entity type from the same hierarchy as the entity set's element type.
- keyValues
-
Type:
System.Collections.Generic.IEnumerable<DbExpression>
A collection of DbExpression s that provide the key values. These expressions must match (in number, type, and order) the key properties of the referenced entity type.
Return Value
Type: System.Data.Entity.Core.Common.CommandTrees.DbRefExpressionA new DbRefExpression that references the element with the specified key values in the given entity set.
Exception | Condition |
---|---|
ArgumentNullException | entitySet or entityType is null, or keyValues is null or contains null. |
ArgumentException | entityType is not from the same hierarchy (a subtype, supertype, or the same type) as entitySet’s element type. |
ArgumentException | The count of keyValues does not match the count of key members declared by the entitySet’s element type, or keyValues contains an expression with a result type that is not compatible with the type of the corresponding key member. |
DbExpressionBuilder.CreateRef Method (EntitySet, IEnumerable<DbExpression>)
Creates a new DbRefExpression that encodes a reference to a specific entity based on key values.
public static DbRefExpression CreateRef( this EntitySet entitySet, IEnumerable<DbExpression> keyValues )
Parameters
- entitySet
-
Type:
System.Data.Entity.Core.Metadata.Edm.EntitySet
The entity set in which the referenced element resides.
- keyValues
-
Type:
System.Collections.Generic.IEnumerable<DbExpression>
A collection of DbExpression s that provide the key values. These expressions must match (in number, type, and order) the key properties of the referenced entity type.
Return Value
Type: System.Data.Entity.Core.Common.CommandTrees.DbRefExpressionA new DbRefExpression that references the element with the specified key values in the given entity set.
Exception | Condition |
---|---|
ArgumentNullException | entitySet is null, or keyValues is null or contains null. |
ArgumentException | The count of keyValues does not match the count of key members declared by the entitySet's element type, or keyValues contains an expression with a result type that is not compatible with the type of the corresponding key member. |