public static void Fetch <T>(this IQueryable <T> querable, Action <FetchResult <T> > action, FetchOptions <T> options) where T : class, new()
{
var dbContext = querable.GetDbContext();
var sqlQuery = SqlBuilder.Parse(querable.ToQueryString());
if (options.InputColumns != null || options.IgnoreColumns != null)
{
var tableMapping = dbContext.GetTableMapping(typeof(T));
IEnumerable <string> columnNames = options.InputColumns != null?options.InputColumns.GetObjectProperties() : tableMapping.GetColumns(true);
IEnumerable <string> columnsToFetch = CommonUtil.FormatColumns(columnNames.Where(o => !options.IgnoreColumns.GetObjectProperties().Contains(o)));
sqlQuery.SelectColumns(columnsToFetch);
}
var command = dbContext.Database.GetDbConnection().CreateCommand();
command.CommandText = sqlQuery.Sql;
command.Parameters.AddRange(sqlQuery.Parameters.ToArray());
var reader = command.ExecuteReader();
List <PropertyInfo> propertySetters = new List <PropertyInfo>();
var entityType = typeof(T);
for (int i = 0; i < reader.FieldCount; i++)
{
propertySetters.Add(entityType.GetProperty(reader.GetName(i)));
}
//Read data
int batch = 1;
int count = 0;
int totalCount = 0;
var entities = new List <T>();
while (reader.Read())
{
var entity = new T();
for (int i = 0; i < reader.FieldCount; i++)
{
var value = reader.GetValue(i);
if (value == DBNull.Value)
{
value = null;
}
propertySetters[i].SetValue(entity, value);
}
entities.Add(entity);
count++;
totalCount++;
if (count == options.BatchSize)
{
action(new FetchResult <T> {
Results = entities, Batch = batch
});
entities.Clear();
count = 0;
batch++;
}
}
if (entities.Count > 0)
{
action(new FetchResult <T> {
Results = entities, Batch = batch
});
}
//close the DataReader
reader.Close();
}
public static void Fetch <T>(this IQueryable <T> querable, Action <FetchResult <T> > action, FetchOptions options) where T : class, new()
{
var dbContext = GetDbContextFromIQuerable(querable);
var dbConnection = dbContext.GetSqlConnection();
//Open datbase connection
if (dbConnection.State == ConnectionState.Closed)
{
dbConnection.Open();
}
var command = new SqlCommand(querable.ToQueryString(), dbConnection);
var reader = command.ExecuteReader();
List <PropertyInfo> propertySetters = new List <PropertyInfo>();
var entityType = typeof(T);
for (int i = 0; i < reader.FieldCount; i++)
{
propertySetters.Add(entityType.GetProperty(reader.GetName(i)));
}
//Read data
int batch = 1;
int count = 0;
int totalCount = 0;
var entities = new List <T>();
while (reader.Read())
{
var entity = new T();
for (int i = 0; i < reader.FieldCount; i++)
{
var value = reader.GetValue(i);
if (value == DBNull.Value)
{
value = null;
}
propertySetters[i].SetValue(entity, value);
}
entities.Add(entity);
count++;
totalCount++;
if (count == options.BatchSize)
{
action(new FetchResult <T> {
Results = entities, Batch = batch
});
entities.Clear();
count = 0;
batch++;
}
}
if (entities.Count > 0)
{
action(new FetchResult <T> {
Results = entities, Batch = batch
});
}
//close the DataReader
reader.Close();
}
