private void AppendSelectFrom(List <Expression <Func <TEntity, object> > > propertySelections)
{
propertySelections?.ForEach(PropertySelectionResolver.ValidatePropertyExpression);
var table = MetadataResolver.TableName <TEntity>();
var selections = PropertySelectionResolver.GetSelectionsFromProperties(propertySelections);
string selectFrom = $"SELECT {selections} FROM {table}";
_sqlBuilder.Append(selectFrom);
}
public SelectFromBuilder <TEntity> Property(Expression <Func <TEntity, TResult> > selection)
{
if (selection == null)
{
throw new ArgumentNullException(nameof(selection), "Property selection expression must be provided.");
}
// validate expression
PropertySelectionResolver.ValidatePropertyExpression(selection);
_selection = selection;
return(this);
}
public (Type propertyType, PostgresDataType dataType) GetMetadata()
{
if (_selection == null)
{
throw new InvalidOperationException("Selection must be configured to get metadata.");
}
if (!PropertySelectionResolver.TryGetColumnFromExpression(_selection, out TableColumn column))
{
throw new InvalidOperationException("Failed to resolve metadata from selection expression.");
}
return(column.PropertyType, column.DataType);
}
public string BuildQuery()
{
var table = MetadataResolver.TableName <TEntity>();
var selection = PropertySelectionResolver.GetSelectionFromProperty(_selection);
string selectFrom = $"SELECT {selection} FROM {table}";
_sqlBuilder.Append(selectFrom);
if (_where != null)
{
var whereCondition = WhereConditionBuilder <TEntity> .FromExpression(_where);
_sqlBuilder.Append($"WHERE {whereCondition}");
}
return(_sqlBuilder.GetResult(omitTerminatingSemiColon: true));
}
