/// <summary>
/// Creates instance of query aggregate function.
/// </summary>
/// <param name="function">Sql function</param>
/// <param name="parameters">Function parameters and expressions</param>
public QueryFunction(QueryAggregateFunction function, params object[] parameters)
{
// Initialize.
PartOfGroupBy = false;
FunctionName = function.ToString().ToUpper();
SeperateParameters(parameters);
}
public string GenerateAggregateQuery(DatabaseQuery query, QueryAggregateFunction function, string propertyName)
{
var sqlFunction = function.ToString();
var columnValueExpression = MapColumn(propertyName);
if (function == QueryAggregateFunction.Average)
{
sqlFunction = "AVG";
var propertyType = query.EntityType.GetProperty(propertyName).PropertyType;
if (propertyType == typeof(int) || propertyType == typeof(int?))
{
columnValueExpression = $"CAST({columnValueExpression} AS decimal)";
}
}
return($"SELECT {sqlFunction}({columnValueExpression}) FROM {GetTables()}" +
GenerateWhere(query));
}