관계는 두 데이터 테이블 간의 연결입니다. 이 관계는 두 테이블의 데이터를 상호 연결하는 방법을 설정합니다.
관계 표현을 만들고 조작하는 방법에 대한 자세한 설명은 관계 표현(테이블 형식) 을 참조하세요.
관계 표현
테이블 형식 모델에서는 두 테이블 간에 여러 관계를 정의할 수 있습니다. 두 테이블 간의 여러 관계가 정의된 경우 하나의 관계만 모델의 기본 관계로 정의할 수 있으며 활성 관계로 이름이 지정됩니다. 다른 모든 관계는 비활성으로 이름이 지정됩니다.
AMO의 관계
AMO 개체의 관점에서 모든 비활성 관계는 1 대 1 매핑 관계의 Relationship 표현을 가지며 다른 주요 AMO 개체는 필요하지 않습니다. 활성 관계에 대한 다른 요구 사항이 존재하고 ReferenceMeasureGroupDimension 매핑도 필요합니다.
다음 코드 조각은 테이블 형식 모델에서 관계를 만드는 방법, 관계를 활성화하는 방법 및 테이블에서 기본 키를 정의하는 방법("RowNumber" 이외의)을 보여 줍니다. 활성 관계를 만들려면 기본 키가 관계의 기본 키 테이블인 PKTableName(관계의 한쪽)에 정의되어야 합니다. 여기에 표시된 샘플은 이 열에 기본 키가 정의되지 않은 경우 PKColumnName에 기본 키를 만듭니다. 기본 키 열에 기본 키가 없어도 비활성 관계를 만들 수 있습니다.
private Boolean createRelationship(string PKTableName, string PKColumnName, string MVTableName, string MVColumnName, AMO.Database tabularDb, string cubeName, Boolean forceActive)
{
//verify input parameters
if( string.IsNullOrEmpty(PKTableName) || string.IsNullOrWhiteSpace(PKTableName)
|| string.IsNullOrEmpty(PKColumnName) || string.IsNullOrWhiteSpace(PKColumnName)
|| string.IsNullOrEmpty(MVTableName) || string.IsNullOrWhiteSpace(MVTableName)
|| string.IsNullOrEmpty(MVColumnName) || string.IsNullOrWhiteSpace(MVColumnName)
|| (tabularDb == null)
) return false;
if(!tabularDb.Dimensions.ContainsName(PKTableName) || !tabularDb.Dimensions.ContainsName(MVTableName)) return false;
if(!tabularDb.Dimensions[PKTableName].Attributes.ContainsName(PKColumnName) || !tabularDb.Dimensions[MVTableName].Attributes.ContainsName(MVColumnName)) return false;
//Verify underlying cube structure
if (!tabularDb.Cubes[cubeName].Dimensions.ContainsName(PKTableName) || !tabularDb.Cubes[cubeName].Dimensions.ContainsName(MVTableName)) return false; //Should return an exception!!
if (!tabularDb.Cubes[cubeName].MeasureGroups.ContainsName(PKTableName) || !tabularDb.Cubes[cubeName].MeasureGroups.ContainsName(MVTableName)) return false; //Should return an exception!!
//Make sure PKTableName.PKColumnName is set as PK ==> <attribute>.usage == AMO.AttributeUsage.Key
if (tabularDb.Dimensions[PKTableName].Attributes[PKColumnName].Usage != AMO.AttributeUsage.Key)
{
//... here we are 'fixing', if there is an issue with PKTableName.PKColumnName not being the PK of the table
setPKColumn(tabularDb, PKTableName, PKColumnName);
}
//Terminology note:
// - the many side of the relationship is named the From end in AMO
// - the PK side of the relationship in named the To end in AMO
//
//It seems relationships flow FROM the many side of the relationship in TO the primary key side of the relationship in AMO
//
//Verify the relationship we are creating does not exist, regardless of name.
//if it exists, return true (no need to recreate it)
//if it doesn't exists it will be created after this validation
//
foreach (AMO.Relationship currentRelationship in tabularDb.Dimensions[MVTableName].Relationships)
{
if ((currentRelationship.FromRelationshipEnd.Attributes[0].AttributeID == MVColumnName)
&& (currentRelationship.ToRelationshipEnd.DimensionID == PKTableName)
&& (currentRelationship.ToRelationshipEnd.Attributes[0].AttributeID == PKColumnName))
{
if (forceActive)
{
//Activate the relationship
setActiveRelationship(tabularDb.Cubes[cubeName], MVTableName, MVColumnName, PKTableName, currentRelationship.ID);
//Update server with changes made here
tabularDb.Update(AMO.UpdateOptions.ExpandFull, AMO.UpdateMode.CreateOrReplace);
tabularDb.Cubes[cubeName].MeasureGroups[MVTableName].Process(AMO.ProcessType.ProcessFull);
}
return true;
}
}
//A relationship like the one to be created does not exist; ergo, let's create it:
//First, create the INACTIVE relationship definitions in the MultipleValues end of the relationship
#region define unique name for relationship
string newRelationshipID = string.Format("Relationship _{0}_{1}_ to _{2}_{3}_", MVTableName, MVColumnName, PKTableName, PKColumnName);
int rootLen = newRelationshipID.Length;
for (int i = 0; tabularDb.Dimensions[MVTableName].Relationships.Contains(newRelationshipID); )
{
newRelationshipID = string.Format("{0}_{1,8:0}", newRelationshipID.Substring(0, rootLen), i);
}
#endregion
AMO.Relationship newRelationship = tabularDb.Dimensions[MVTableName].Relationships.Add(newRelationshipID);
newRelationship.FromRelationshipEnd.DimensionID = MVTableName;
newRelationship.FromRelationshipEnd.Attributes.Add(MVColumnName);
newRelationship.FromRelationshipEnd.Multiplicity = AMO.Multiplicity.Many;
newRelationship.FromRelationshipEnd.Role = string.Empty;
newRelationship.ToRelationshipEnd.DimensionID = PKTableName;
newRelationship.ToRelationshipEnd.Attributes.Add(PKColumnName);
newRelationship.ToRelationshipEnd.Multiplicity = AMO.Multiplicity.One;
newRelationship.ToRelationshipEnd.Role = string.Empty;
//Update server to create relationship
tabularDb.Update(AMO.UpdateOptions.ExpandFull, AMO.UpdateMode.UpdateOrCreate);
tabularDb.Dimensions[MVTableName].Process(AMO.ProcessType.ProcessDefault);
tabularDb.Dimensions[PKTableName].Process(AMO.ProcessType.ProcessDefault);
//Second, activate the relationship if relationship is to be set as the active relationship: 'forceActive==true'
//... an inactive relationship needs only to be created on the dimensions object
if (forceActive)
{
//Activate the relationship
setActiveRelationship(tabularDb.Cubes[cubeName], MVTableName, MVColumnName, PKTableName, newRelationshipID);
}
return true;
}
private void setActiveRelationship(AMO.Cube currentCube, string MVTableName, string MVColumnName, string PKTableName, string relationshipID)
{
if (!currentCube.MeasureGroups.Contains(MVTableName))
{
throw new AMO.AmoException(string.Format("Cube [{0}] does not contain Measure Group [{1}]\nError activating relationship [{2}]: [{4}] <--- [{1}].[{3}]"
, currentCube.Name, MVTableName, relationshipID, MVColumnName, PKTableName));
}
AMO.MeasureGroup currentMG = currentCube.MeasureGroups[MVTableName];
if (!currentMG.Dimensions.Contains(PKTableName))
{
AMO.ReferenceMeasureGroupDimension newReferenceMGDim = new AMO.ReferenceMeasureGroupDimension();
newReferenceMGDim.CubeDimensionID = PKTableName;
newReferenceMGDim.IntermediateCubeDimensionID = MVTableName;
newReferenceMGDim.IntermediateGranularityAttributeID = MVColumnName;
newReferenceMGDim.Materialization = AMO.ReferenceDimensionMaterialization.Regular;
newReferenceMGDim.RelationshipID = relationshipID;
foreach (AMO.CubeAttribute PKAttribute in currentCube.Dimensions[PKTableName].Attributes)
{
AMO.MeasureGroupAttribute PKMGAttribute = newReferenceMGDim.Attributes.Add(PKAttribute.AttributeID);
OleDbType PKMGAttributeType = PKAttribute.Attribute.KeyColumns[0].DataType;
PKMGAttribute.KeyColumns.Add(new AMO.DataItem(PKTableName, PKAttribute.AttributeID, PKMGAttributeType));
PKMGAttribute.KeyColumns[0].Source = new AMO.ColumnBinding(PKTableName, PKAttribute.AttributeID);
}
currentMG.Dimensions.Add(newReferenceMGDim);
AMO.ValidationErrorCollection errors = new AMO.ValidationErrorCollection();
newReferenceMGDim.Validate(errors, true);
if (errors.Count > 0)
{
StringBuilder errorMessages = new StringBuilder();
foreach (AMO.ValidationError err in errors)
{
errorMessages.AppendLine(string.Format("At {2}: # {0} : {1}", err.ErrorCode, err.FullErrorText, err.Source));
}
throw new AMO.AmoException(errorMessages.ToString());
}
//Update changes in the server
currentMG.Update(AMO.UpdateOptions.ExpandFull, AMO.UpdateMode.CreateOrReplace);
}
else
{
AMO.ReferenceMeasureGroupDimension currentReferenceMGDim = (AMO.ReferenceMeasureGroupDimension)currentMG.Dimensions[PKTableName];
currentReferenceMGDim.RelationshipID = relationshipID;
currentReferenceMGDim.IntermediateGranularityAttributeID = MVColumnName;
//Update changes in the server
currentMG.Update(AMO.UpdateOptions.ExpandFull, AMO.UpdateMode.UpdateOrCreate);
}
//process MG to activate relationship
currentMG.Process(AMO.ProcessType.ProcessFull);
}
private void setPKColumn(AMO.Database tabularDb, string PKTableName, string PKColumnName)
{
//Find all 'unwanted' Key attributes, remove their Key definitions and include the attributes in the ["RowNumber"].AttributeRelationships
foreach (AMO.DimensionAttribute currentDimAttribute in tabularDb.Dimensions[PKTableName].Attributes)
{
if ((currentDimAttribute.Usage == AMO.AttributeUsage.Key) && (currentDimAttribute.ID != PKColumnName))
{
currentDimAttribute.Usage = AMO.AttributeUsage.Regular;
if (currentDimAttribute.ID != "RowNumber")
{
currentDimAttribute.KeyColumns[0].NullProcessing = AMO.NullProcessing.Preserve;
currentDimAttribute.AttributeRelationships.Clear();
if (!tabularDb.Dimensions[PKTableName].Attributes["RowNumber"].AttributeRelationships.ContainsName(currentDimAttribute.ID))
{
AMO.DimensionAttribute currentAttribute = tabularDb.Dimensions[PKTableName].Attributes[currentDimAttribute.ID];
AMO.AttributeRelationship currentAttributeRelationship = tabularDb.Dimensions[PKTableName].Attributes["RowNumber"].AttributeRelationships.Add(currentAttribute.ID);
currentAttributeRelationship.OverrideBehavior = AMO.OverrideBehavior.None;
}
tabularDb.Dimensions[PKTableName].Attributes["RowNumber"].AttributeRelationships[currentDimAttribute.ID].Cardinality = AMO.Cardinality.Many;
}
}
}
//Remove PKColumnName from ["RowNumber"].AttributeRelationships
int PKAtribRelationshipPosition = tabularDb.Dimensions[PKTableName].Attributes["RowNumber"].AttributeRelationships.IndexOf(PKColumnName);
if (PKAtribRelationshipPosition != -1) tabularDb.Dimensions[PKTableName].Attributes["RowNumber"].AttributeRelationships.RemoveAt(PKAtribRelationshipPosition, true);
//Define PKColumnName as Key and add ["RowNumber"] to PKColumnName.AttributeRelationships with cardinality of One
tabularDb.Dimensions[PKTableName].Attributes[PKColumnName].Usage = AMO.AttributeUsage.Key;
tabularDb.Dimensions[PKTableName].Attributes[PKColumnName].KeyColumns[0].NullProcessing = AMO.NullProcessing.Error;
if (!tabularDb.Dimensions[PKTableName].Attributes[PKColumnName].AttributeRelationships.ContainsName("RowNumber"))
{
AMO.DimensionAttribute currentAttribute = tabularDb.Dimensions[PKTableName].Attributes["RowNumber"];
AMO.AttributeRelationship currentAttributeRelationship = tabularDb.Dimensions[PKTableName].Attributes[PKColumnName].AttributeRelationships.Add(currentAttribute.ID);
currentAttributeRelationship.OverrideBehavior = AMO.OverrideBehavior.None;
}
tabularDb.Dimensions[PKTableName].Attributes[PKColumnName].AttributeRelationships["RowNumber"].Cardinality = AMO.Cardinality.One;
//Update Table before going creating the relationship
tabularDb.Update(AMO.UpdateOptions.ExpandFull, AMO.UpdateMode.UpdateOrCreate);
tabularDb.Dimensions[PKTableName].Process(AMO.ProcessType.ProcessDefault);
}
AMO2Tabular 샘플
그러나 AMO를 사용하여 관계 표현을 만들고 조작하는 방법을 이해하려면 AMO에서 테이블 형식으로의 소스 코드를 참조하세요. 샘플은 Codeplex에서 사용할 수 있습니다. 코드에 대한 중요한 참고 사항: 코드는 여기에 설명된 논리적 개념에 대한 지원으로만 제공되며 프로덕션 환경에서 사용하면 안 됩니다. 교육학 이외의 다른 용도로 사용해서는 안 됩니다.