public IEnumerable <T> ExecuteCollection <T>(QueryModel queryModel)
{
this.visitor.VisitQueryModel(queryModel);
var cmd = this.visitor.BuildSqlQuery();
var projector = this.GetSelectProj <T>(queryModel);
cmd.Connection = ExcelHelperClass.GetConnection(this.args);
if (cmd.Connection.State == System.Data.ConnectionState.Closed)
{
cmd.Connection.Open();
}
cmd.Parameters.AddRange(this.visitor.Builder.Params.ToArray());
var data = cmd.ExecuteReader();
var objData = this.GetDataObj(queryModel, data);
var resultObject = objData.Cast(projector);
return(resultObject);
}
protected override Expression VisitMemberExpression(MemberExpression expression)
{
var prop = expression.Member as PropertyInfo;
var columns = ExcelHelperClass.GetColumnNames(args);
if (prop == null)
{
return(expression);
}
var columnNameProp = prop.GetCustomAttribute <ExcelColumnAttribute>();
if (!columns.Contains(columnNameProp.ColumnName))
{
throw new MappingException(columnNameProp.ColumnName, this.args);
}
this.whereClause.Append($" {columnNameProp.ColumnName} ");
return(expression);
}
private IEnumerable <object> GetDataObj(QueryModel queryModel, IDataReader data)
{
var results = new List <object>();
while (data.Read())
{
var obj = Activator.CreateInstance(queryModel.MainFromClause.ItemType);
var props = obj.GetType().GetProperties();
var columns = ExcelHelperClass.GetColumnNames(this.args);
foreach (var prop in props)
{
var columnNameProp = prop.GetCustomAttribute <ExcelColumnAttribute>();
if (!columns.Contains(columnNameProp.ColumnName))
{
throw new MappingException(columnNameProp.ColumnName, this.args);
}
prop.SetValue(obj, data[columnNameProp.ColumnName]);
}
results.Add(obj);
}
return(results);
}