TableRequestInfo
Overview
TableRequestInfo allows you to specify additional parameters for querying certain schema tables.
With TableRequestInfo you can:
- specify custom parameters for getting data from parametrized schema tables.
- specify if schema information is received inside the encoded schema table data.
- specify the count of records you want to obtain.
Instances of the TableRequestInfo class are usually created on the client side and then passed into certain overloads of the DataAdapter.Fill method. Further TableRequestInfo will be serialized into GetData request that will be sent to the server.
Note: Delphi users do not need to deal with TableRequestInfo directly. It will be created automatically by the TDABaseDataAdapter when working with data tables.
Location
- Unit: DataAbstract4_Intf.pas
- Ancestry: TCollectionItem | TROComplexType | TableRequestInfo
constructor Create reintroduce overload virtual (declared in TROComplexType)
Creates a new instance.
constructor Create
constructor Create (TCollection) override
Creates a new instance with given parameter.
constructor Create(aCollection: TCollection)
Parameters:
- aCollection: collection
Assign override
Copies data from a given source.
procedure Assign(Source: TPersistent)
Parameters:
- Source: Instance whose properties will be copied
AssignTo override (declared in TROComplexType)
Copies the properties of an object to a destination object.
procedure AssignTo(iDest: TPersistent)
Parameters:
- iDest: destination object.
Clone (declared in TROComplexType)
Creates and returns a second copy of the struct.
The new instance will be a deep copy of the original struct, all nested members that are arrays, structs or binaries will be duplicated as part of the cloning process, so that the new instance and its members will be completely independent from the original class.
function Clone: TROComplexType
ContentAsJson (declared in TROComplexType)
property ContentAsJson: UnicodeString read
ContentAsString (declared in TROComplexType)
Returns the structure of the type in a string format.
property ContentAsString: string read
ContentAsXml (declared in TROComplexType)
Returns the XML structure of the type in a string format.
property ContentAsXml: ROUTF8String read
FieldCount (declared in TROComplexType)
property FieldCount: Integer read
FieldInfo (declared in TROComplexType)
property FieldInfo[Index: Integer]: PTypeInfo read
FieldName (declared in TROComplexType)
property FieldName[Index: Integer]: string read
FreeInternalProperties protected override
procedure FreeInternalProperties
GetAttributeCount virtual (declared in TROComplexType)
Returns the number of custom attributes defined for the class.
class function GetAttributeCount: Integer
GetAttributeName virtual (declared in TROComplexType)
Returns the name of custom attribute defined for the class, with the specified index.
class function GetAttributeName(aIndex: Integer): string
Parameters:
- aIndex: The index of attribute.
GetAttributeValue virtual (declared in TROComplexType)
Returns the value of custom attribute defined for the class, with the specified index.
class function GetAttributeValue(aIndex: Integer): string
Parameters:
- aIndex: The index of attribute.
GetContentAsJson (declared in TROComplexType)
function GetContentAsJson(aIncludeExtraInfo: Boolean): UnicodeString
Parameters:
- aIncludeExtraInfo:
GetContentAsXml (declared in TROComplexType)
function GetContentAsXml(aOffset: Integer): ROUTF8String
Parameters:
- aOffset:
GetFieldNames (declared in TROComplexType)
procedure GetFieldNames(aList: TStrings)
Parameters:
- aList:
GetFieldValue (declared in TROComplexType)
function GetFieldValue(const aFieldName: string): Variant
Parameters:
- aFieldName:
IncludeSchema
Boolean property that specifies if table schema info s needed inside the result stream (true) or not (false, default). Usually, the client side already knows the schema, so passing the schema with the table data will cause some overhead, but if you need to update table schema info on the client side, you need to set that property to true.
For example, in DA for .NET you can create a new DataTable and try to fill it with data from a specified table. Since the structure for the new DataTable is not defined yet, you can establish to put the schema info with the table data, thus giving the data table a proper structure before it will be filled.
property IncludeSchema: Boolean read write
MaxRecords
This property allows to limit the count of rows of the request. Put it as -1 to receive all available records. 0 value will update the table schema without receiving any data.
Limiting the amount of transferred rows can reduce traffic between the DataAbstract server (middle tier) and the DataAbstract client (front-end tier). It will not affect traffic between the database and the DataAbstract server. For reducing traffic between the database and the DataAbstract server, you have to use other approaches, like Dynamic Where.
property MaxRecords: Integer read write
Parameters
Represents the array of the DataParameters for getting data from parametrized schema tables.
property Parameters: DataParameterArray read write
ReadComplex override
Deserializes current class instance using provided serializer.
procedure ReadComplex(aSerializer: TObject)
Parameters:
- aSerializer: Data source (type TROSerializer).
SaveToJson protected virtual (declared in TROComplexType)
procedure SaveToJson(const aRoot: TROJSONValue; aIncludeExtraInfo: Boolean)
Parameters:
- aRoot:
- aIncludeExtraInfo:
SaveToXml protected virtual (declared in TROComplexType)
procedure SaveToXml(const aNode: TROConverterNode)
Parameters:
- aNode:
SetFieldValue (declared in TROComplexType)
procedure SetFieldValue(const aFieldName: string; const aValue: Variant)
Parameters:
- aFieldName:
- aValue:
SmartAssign (declared in TROComplexType)
Copies specific data from a given source.
procedure SmartAssign(Source: TPersistent; TypeKinds: TTypeKinds)
Parameters:
- Source: Instance whose properties will be copied
- TypeKinds: Specifies which properties should be copied
TryGetAttribute (declared in TROComplexType)
class function TryGetAttribute(aName: string; out aValue: string): Boolean
Parameters:
- aName:
- aValue:
UserFilter
Uses for specifying custom conditions for returning rows. For example, "CustomerType < 100". Note that all records will be read from the database, but only those that fit the custom condition will be passed to the client.
property UserFilter: ROUTF8String read write
WriteComplex override
Serializes current class instance using provided serializer.
procedure WriteComplex(aSerializer: TObject)
Parameters:
- aSerializer: Data sink (type TROSerializer)
ContentAsJson (declared in TROComplexType)
property ContentAsJson: UnicodeString read
ContentAsString (declared in TROComplexType)
Returns the structure of the type in a string format.
property ContentAsString: string read
ContentAsXml (declared in TROComplexType)
Returns the XML structure of the type in a string format.
property ContentAsXml: ROUTF8String read
FieldCount (declared in TROComplexType)
property FieldCount: Integer read
FieldInfo (declared in TROComplexType)
property FieldInfo[Index: Integer]: PTypeInfo read
FieldName (declared in TROComplexType)
property FieldName[Index: Integer]: string read
IncludeSchema
Boolean property that specifies if table schema info s needed inside the result stream (true) or not (false, default). Usually, the client side already knows the schema, so passing the schema with the table data will cause some overhead, but if you need to update table schema info on the client side, you need to set that property to true.
For example, in DA for .NET you can create a new DataTable and try to fill it with data from a specified table. Since the structure for the new DataTable is not defined yet, you can establish to put the schema info with the table data, thus giving the data table a proper structure before it will be filled.
property IncludeSchema: Boolean read write
MaxRecords
This property allows to limit the count of rows of the request. Put it as -1 to receive all available records. 0 value will update the table schema without receiving any data.
Limiting the amount of transferred rows can reduce traffic between the DataAbstract server (middle tier) and the DataAbstract client (front-end tier). It will not affect traffic between the database and the DataAbstract server. For reducing traffic between the database and the DataAbstract server, you have to use other approaches, like Dynamic Where.
property MaxRecords: Integer read write
Parameters
Represents the array of the DataParameters for getting data from parametrized schema tables.
property Parameters: DataParameterArray read write
UserFilter
Uses for specifying custom conditions for returning rows. For example, "CustomerType < 100". Note that all records will be read from the database, but only those that fit the custom condition will be passed to the client.
property UserFilter: ROUTF8String read write
GetAttributeCount virtual (declared in TROComplexType)
Returns the number of custom attributes defined for the class.
class function GetAttributeCount: Integer
GetAttributeName virtual (declared in TROComplexType)
Returns the name of custom attribute defined for the class, with the specified index.
class function GetAttributeName(aIndex: Integer): string
Parameters:
- aIndex: The index of attribute.
GetAttributeValue virtual (declared in TROComplexType)
Returns the value of custom attribute defined for the class, with the specified index.
class function GetAttributeValue(aIndex: Integer): string
Parameters:
- aIndex: The index of attribute.
TryGetAttribute (declared in TROComplexType)
class function TryGetAttribute(aName: string; out aValue: string): Boolean
Parameters:
- aName:
- aValue:
constructor Create reintroduce overload virtual (declared in TROComplexType)
Creates a new instance.
constructor Create
constructor Create (TCollection) override
Creates a new instance with given parameter.
constructor Create(aCollection: TCollection)
Parameters:
- aCollection: collection
Assign override
Copies data from a given source.
procedure Assign(Source: TPersistent)
Parameters:
- Source: Instance whose properties will be copied
AssignTo override (declared in TROComplexType)
Copies the properties of an object to a destination object.
procedure AssignTo(iDest: TPersistent)
Parameters:
- iDest: destination object.
Clone (declared in TROComplexType)
Creates and returns a second copy of the struct.
The new instance will be a deep copy of the original struct, all nested members that are arrays, structs or binaries will be duplicated as part of the cloning process, so that the new instance and its members will be completely independent from the original class.
function Clone: TROComplexType
FreeInternalProperties protected override
procedure FreeInternalProperties
GetContentAsJson (declared in TROComplexType)
function GetContentAsJson(aIncludeExtraInfo: Boolean): UnicodeString
Parameters:
- aIncludeExtraInfo:
GetContentAsXml (declared in TROComplexType)
function GetContentAsXml(aOffset: Integer): ROUTF8String
Parameters:
- aOffset:
GetFieldNames (declared in TROComplexType)
procedure GetFieldNames(aList: TStrings)
Parameters:
- aList:
GetFieldValue (declared in TROComplexType)
function GetFieldValue(const aFieldName: string): Variant
Parameters:
- aFieldName:
ReadComplex override
Deserializes current class instance using provided serializer.
procedure ReadComplex(aSerializer: TObject)
Parameters:
- aSerializer: Data source (type TROSerializer).
SaveToJson protected virtual (declared in TROComplexType)
procedure SaveToJson(const aRoot: TROJSONValue; aIncludeExtraInfo: Boolean)
Parameters:
- aRoot:
- aIncludeExtraInfo:
SaveToXml protected virtual (declared in TROComplexType)
procedure SaveToXml(const aNode: TROConverterNode)
Parameters:
- aNode:
SetFieldValue (declared in TROComplexType)
procedure SetFieldValue(const aFieldName: string; const aValue: Variant)
Parameters:
- aFieldName:
- aValue:
SmartAssign (declared in TROComplexType)
Copies specific data from a given source.
procedure SmartAssign(Source: TPersistent; TypeKinds: TTypeKinds)
Parameters:
- Source: Instance whose properties will be copied
- TypeKinds: Specifies which properties should be copied
WriteComplex override
Serializes current class instance using provided serializer.
procedure WriteComplex(aSerializer: TObject)
Parameters:
- aSerializer: Data sink (type TROSerializer)
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TableRequestInfo Class:
- .NET
- Xcode
- Delphi