/// <summary>
/// Create a representation of the creation of a data relation.
/// </summary>
/// <param name="relationSchema">The description of a relationship between two tables.</param>
public CodeDataRelation(RelationSchema relationSchema)
{
// Collect the key fields in the parent table.
List <CodeExpression> parentFieldList = new List <CodeExpression>();
foreach (ColumnSchema columnSchema in relationSchema.ParentColumns)
{
parentFieldList.Add(new CodePropertyReferenceExpression(new CodeFieldReferenceExpression(new CodeTypeReferenceExpression(relationSchema.ParentTable.DataModel.Name), String.Format("table{0}", relationSchema.ParentTable.Name)), String.Format("{0}Column", columnSchema.Name)));
}
// Collect the referenced fields in the child table.
List <CodeExpression> childFieldList = new List <CodeExpression>();
foreach (ColumnSchema columnSchema in relationSchema.ChildColumns)
{
childFieldList.Add(new CodePropertyReferenceExpression(new CodeFieldReferenceExpression(new CodeTypeReferenceExpression(relationSchema.ChildTable.DataModel.Name), String.Format("table{0}", relationSchema.ChildTable.Name)), String.Format("{0}Column", columnSchema.Name)));
}
// new System.Data.ForeignKeyConstraint("FK_Object_Department", new Teraque.DataModelGenerator.Column[] {
// Teraque.UnitTest.Server.DataModel.tableObject.ObjectIdColumn}, new Teraque.DataModelGenerator.Column[] {
// Teraque.UnitTest.Server.DataModel.tableDepartment.DepartmentIdColumn});
this.CreateType = new CodeGlobalTypeReference(typeof(DataRelation));
this.Parameters.Add(new CodePrimitiveExpression(relationSchema.Name));
this.Parameters.Add(new CodeArrayCreateExpression(new CodeGlobalTypeReference(typeof(DataColumn)), parentFieldList.ToArray()));
this.Parameters.Add(new CodeArrayCreateExpression(new CodeGlobalTypeReference(typeof(DataColumn)), childFieldList.ToArray()));
this.Parameters.Add(new CodePrimitiveExpression(false));
}
/// <summary>
/// The foreign constraints can only be evaluated after all the tables, keys and unique constraints have been evaluated.
/// </summary>
/// <param name="xmlSchema"></param>
private void SecondPass(XmlSchemaSet xmlSchemaSet)
{
// This is the second pass through the schemas. Once the tables, keys and unique constraints have been evaluated,
// then the foreign constraints can be constructed and applied to the parent and child tables.
foreach (XmlSchemaElement xmlSchemaElement in xmlSchemaSet.GlobalElements.Values)
{
// Only the Microsoft DataSet element is evaluated for foreign keys.
if (ObjectSchema.IsDataSetElement(xmlSchemaElement))
{
// This will examine each of the constraints looking for a foreign key description.
foreach (XmlSchemaIdentityConstraint xmlSchemaIdentityConstraint in xmlSchemaElement.Constraints)
{
// Evaluate the foreign keys in the data model.
if (xmlSchemaIdentityConstraint is XmlSchemaKeyref)
{
// This object can be used as a foreign key constraint and, optionally, can be used to describe a
// parent/child relationship.
XmlSchemaKeyref xmlSchemaKeyref = xmlSchemaIdentityConstraint as XmlSchemaKeyref;
// This creates a foreign key.
ForeignKeyConstraintSchema foreignKeyConstraintSchema = new ForeignKeyConstraintSchema(this, xmlSchemaIdentityConstraint as XmlSchemaKeyref);
// Foreign constraint schemas are always added to the list of constraints on a table. They can also
// conditionally become the source for a relationship between two tables.
foreignKeyConstraintSchema.Table.Add(foreignKeyConstraintSchema);
// Unless specifically instructed to supress the relation, it will be created add added to both the
// parent and child tables as well as the data model.
XmlAttribute isConstraintOnlyAttribute = ObjectSchema.GetUnhandledAttribute(xmlSchemaIdentityConstraint, QualifiedName.ConstraintOnly);
if (isConstraintOnlyAttribute == null || !Convert.ToBoolean(isConstraintOnlyAttribute.Value))
{
RelationSchema relationSchema = new RelationSchema(this, xmlSchemaKeyref);
relationSchema.ParentTable.ChildRelations.Add(relationSchema.Name, relationSchema);
relationSchema.ChildTable.ParentRelations.Add(relationSchema.Name, relationSchema);
this.Relations.Add(relationSchema.Name, relationSchema);
}
}
}
}
}
}
