public JoinRecordProvider(IRecordProvider leftProvider, IRecordProvider rightProvider, string leftField,
string rightField)
{
this.leftProvider = leftProvider;
this.rightProvider = rightProvider;
this.leftField = leftField;
this.rightField = rightField;
if (!leftProvider.MetaData.ColumnDescriptors.ContainsKey(leftField))
{
throw new MalformedQueryException($"No field named {leftField} found.");
}
if (!rightProvider.MetaData.ColumnDescriptors.ContainsKey(rightField))
{
throw new MalformedQueryException($"No field named {rightField} found.");
}
var leftDescriptor = leftProvider.MetaData.ColumnDescriptors[leftField];
var rightDescriptor = rightProvider.MetaData.ColumnDescriptors[rightField];
if (leftDescriptor.Type !=
rightDescriptor.Type)
{
throw new MalformedQueryException($"Field types {leftDescriptor.Type} and {rightDescriptor.Type} dont't match.");
}
var allKeys =
leftProvider.MetaData.ColumnDescriptors.Keys.Union(rightProvider.MetaData.ColumnDescriptors.Keys);
MetaData = new RecordMetaData();
foreach (var key in allKeys)
{
if (leftProvider.MetaData.ColumnDescriptors.Keys.Contains(key))
{
MetaData.AddField(
key,
leftProvider.MetaData.ColumnDescriptors[key].Type,
leftProvider.MetaData.ColumnDescriptors[key].Width
);
}
else
{
MetaData.AddField(
key,
rightProvider.MetaData.ColumnDescriptors[key].Type,
rightProvider.MetaData.ColumnDescriptors[key].Width
);
}
}
}
public PracticeDatabaseReader(string filename, IndexManager indexManager,
IEnumerable<IWhereQueryConstraint> constraints, QueryMode queryMode = QueryMode.Auto)
: base(filename, indexManager, constraints, queryMode)
{
recordMetaData = new RecordMetaData();
recordMetaData.AddField("date", ColumnType.Int);
recordMetaData.AddField("id", ColumnType.String, 6);
recordMetaData.AddField("name", ColumnType.String, 40);
recordMetaData.AddField("center_name", ColumnType.String, 40);
recordMetaData.AddField("address", ColumnType.String, 40);
recordMetaData.AddField("city", ColumnType.String, 40);
recordMetaData.AddField("region", ColumnType.String, 40);
recordMetaData.AddField("postal_code", ColumnType.String, 10);
RecordWidth = recordMetaData.RecordWitdh;
}
public SelectionRecordProvider(IEnumerable<string> fields, IRecordProvider provider) : base(provider)
{
this.fields = fields;
MetaData = new RecordMetaData();
foreach (string field in fields)
{
try
{
var underlyingColumn = provider.MetaData.ColumnDescriptors[field];
MetaData.AddField(field, underlyingColumn.Type, underlyingColumn.Width);
}
catch (Exception e)
{
throw new MalformedQueryException($"No field named {field} found.");
}
}
}
protected AggregateRecordProvider(string groupBy, string aggregatedField, IRecordProvider provider)
: base(provider)
{
this.groupBy = groupBy;
this.aggregatedField = aggregatedField;
if (!provider.MetaData.ColumnDescriptors.ContainsKey(groupBy))
{
throw new MalformedQueryException($"Aggregated table does not contain a field '{groupBy}'");
}
if (!provider.MetaData.ColumnDescriptors.ContainsKey(aggregatedField))
{
throw new MalformedQueryException($"Aggregated table does not contain a field '{aggregatedField}'");
}
MetaData = new RecordMetaData();
MetaData.AddField(groupBy, ColumnType.String, provider.MetaData.ColumnDescriptors[groupBy].Width);
if (provider.MetaData.ColumnDescriptors.Count > 2)
{
this.provider = new SelectionRecordProvider(new List<string> {groupBy, aggregatedField}, provider);
}
}