public static IEnumerable <T> IncludeRelation <T>(this IEnumerable <T> source, string dataSourceName,
params Expression <Func <T, object> >[] path) where T : DataModel, new()
{
var schema = new DataSourceSchema <T>();
//Table Relations Map
//To be sent to the DB Lib for SQL Query generation
var tableRelationsMap = new List <SqlJoinRelation>();
//This will hold the information about the sub joins object types
var expressionLookup = new Dictionary <string, string>();
foreach (var t in path)
{
var memberExpression = t.Body as MemberExpression;
if (memberExpression != null)
{
expressionLookup.Add(memberExpression.Member.Name, t.Body.Type.Name);
}
}
var dbRelationsList = schema.DataFields.Where(field => field.Relation != null &&
expressionLookup.Values.Contains(
field.Relation.WithDataModel.Name) &&
expressionLookup.Keys.Contains(field.Name)
).
Select(field => field.Relation).
ToList();
//Start processing the list of table relations
if (dbRelationsList.Any())
{
//Foreach relation in the relations list, process it and construct the big TablesRelationsMap
foreach (var relation in dbRelationsList)
{
//Create a temporary map for this target table relation
var joinedTableInfo = new SqlJoinRelation();
//Get the data model we're in relation with.
var relationType = relation.WithDataModel;
//Build a data source schema for the data model we're in relation with.
var generalModelSchemaType = typeof(DataSourceSchema <>);
var specialModelSchemaType = generalModelSchemaType.MakeGenericType(relationType);
dynamic joinedModelSchema = Activator.CreateInstance(specialModelSchemaType);
//Get it's Data Fields.
List <DataField> joinedModelFields = joinedModelSchema.GetDataFields();
//Get the table column names - exclude the ID field name.
var joinedModelTableColumns = joinedModelFields
.Where(field => field.TableField != null)
.Select(field => field.TableField.ColumnName)
.ToList();
//Get the field that describes the relation key from the target model schema
var joinedModelKey =
joinedModelFields.Find(item => item.TableField != null && item.Name == relation.OnDataModelKey);
//Get the field that describes our key on which we are in relation with the target model
var thisKey =
schema.DataFields.Find(item => item.TableField != null && item.Name == relation.ThisKey);
if (thisKey != null && joinedModelKey != null)
{
//Initialize the temporary map and add it to the original relations map
joinedTableInfo.RelationName = relation.RelationName;
joinedTableInfo.RelationType = relation.RelationType;
joinedTableInfo.MasterTableName = dataSourceName;
joinedTableInfo.MasterTableKey = thisKey.TableField.ColumnName;
joinedTableInfo.JoinedTableName = joinedModelSchema.GetDataSourceName();
joinedTableInfo.JoinedTableKey = joinedModelKey.TableField.ColumnName;
joinedTableInfo.JoinedTableColumns = joinedModelTableColumns;
//Add the relation keys to the TableRelationsMap
tableRelationsMap.Add(joinedTableInfo);
}
} //end-foreach
} //end-outer-if
//Get our table columns from the schema
var thisModelTableColumns = schema.DataFields
.Where(field => field.TableField != null)
.Select(
field => field.TableField.ColumnName)
.ToList();
var dt = DbRoutines.SELECT_WITH_JOIN(dataSourceName, thisModelTableColumns, null, tableRelationsMap, 0);
return(dt.ConvertToList(path));
}
public static T GetWithRelations <T>(this T source, params Expression <Func <T, object> >[] path)
where T : DataModel, new()
{
var schema = new DataSourceSchema <T>();
// Table Relations Map
// To be sent to the DB Lib for SQL Query generation
var tableRelationsMap = new List <SqlJoinRelation>();
//
// Database related
// Where conditions dictionary
//var finalDataSourceName = string.Empty;
var whereConditions = new Dictionary <string, object>();
// This will hold the information about the sub joins object types
var expressionLookup = path.ToDictionary(t =>
{
var memberExpression = t.Body as MemberExpression;
return(memberExpression != null ? memberExpression.Member.Name : null);
}, t => t.Body.Type.Name);
//
// Get the Relations Fields from the Schema
var dbRelationsList = schema.DataFields
.Where(field =>
field.Relation != null &&
expressionLookup.Values.Contains(field.Relation.WithDataModel.Name) &&
expressionLookup.Keys.Contains(field.Name))
.Select(field => field.Relation).
ToList();
//
// Start processing the list of table relations
if (dbRelationsList.Any())
{
//Foreach relation in the relations list, process it and construct the big TablesRelationsMap
foreach (var relation in dbRelationsList)
{
//Create a temporary map for this target table relation
var joinedTableInfo = new SqlJoinRelation();
//Get the data model we're in relation with.
var relationType = relation.WithDataModel;
//Build a data source schema for the data model we're in relation with.
var generalModelSchemaType = typeof(DataSourceSchema <>);
var specialModelSchemaType = generalModelSchemaType.MakeGenericType(relationType);
dynamic joinedModelSchema = Activator.CreateInstance(specialModelSchemaType);
//Get it's Data Fields.
List <DataField> joinedModelFields = joinedModelSchema.GetDataFields();
//Get the table column names - exclude the ID field name.
var joinedModelTableColumns = joinedModelFields
.Where(field => field.TableField != null)
.Select(field => field.TableField.ColumnName)
.ToList();
//Get the field that describes the relation key from the target model schema
var joinedModelKey =
joinedModelFields.Find(item => item.TableField != null && item.Name == relation.OnDataModelKey);
//Get the field that describes our key on which we are in relation with the target model
var thisKey =
schema.DataFields.Find(item => item.TableField != null && item.Name == relation.ThisKey);
if (thisKey != null && joinedModelKey != null)
{
//Initialize the temporary map and add it to the original relations map
joinedTableInfo.RelationName = relation.RelationName;
joinedTableInfo.RelationType = relation.RelationType;
joinedTableInfo.MasterTableName = schema.DataSourceName;
joinedTableInfo.MasterTableKey = thisKey.TableField.ColumnName;
joinedTableInfo.JoinedTableName = joinedModelSchema.GetDataSourceName();
joinedTableInfo.JoinedTableKey = joinedModelKey.TableField.ColumnName;
joinedTableInfo.JoinedTableColumns = joinedModelTableColumns;
//Add the relation keys to the TableRelationsMap
tableRelationsMap.Add(joinedTableInfo);
}
} //end-foreach
} //end-outer-if
//
// Get the ID Field to find the relations for.
// If the ID Field was not found, return an empty instance of the object.
var idField = schema.DataFields.Find(field => field.TableField != null && field.TableField.IsIdField);
if (idField != null)
{
var dataObjectAttr = source.GetType().GetProperty(idField.Name);
var dataObjectAttrValue = dataObjectAttr.GetValue(source, null);
// Put the ID Field in the WHERE CONDITIONS
if (dataObjectAttrValue != null)
{
whereConditions.Add(idField.TableField.ColumnName,
Convert.ChangeType(dataObjectAttrValue, idField.TableField.FieldType));
}
else
{
return(source);
}
}
else
{
return(source);
}
//
// Get our table columns from the schema
var thisModelTableColumns = schema.DataFields
.Where(field => field.TableField != null)
.Select(
field => field.TableField.ColumnName)
.ToList();
//
// Query the data-srouce
var dt = DbRoutines.SELECT_WITH_JOIN(schema.DataSourceName, thisModelTableColumns, whereConditions,
tableRelationsMap, 1);
// Return data
var data = dt.ConvertToList(path);
if (data != null && data.Count > 0)
{
return(data.First());
}
return(source);
}
