/// <summary>
///
/// </summary>
public long Count <ItemType>(MatchExpression matchExpression)
where ItemType : class, IDBPersistent
{
TracerHelper.TraceEntry(typeof(ItemType).Name);
string tableName = _tablesTypeNames[typeof(ItemType)];
StringBuilder commandText = new StringBuilder();
commandText.Append("SELECT count(*) FROM " + tableName);
if (matchExpression != null && matchExpression.ClauseCount > 0)
{
commandText.Append(" WHERE ");
}
_countMutex.WaitOne();
SQLiteCommand command;
long result = 0;
try
{
using (SQLiteConnection connection = GenerateConnection())
{
using (command = new SQLiteCommand(connection))
{
if (matchExpression != null)
{
matchExpression.SetupCommandParameters(command, commandText);
}
command.CommandText = commandText.ToString();
connection.Open();
result = (long)command.ExecuteScalar();
}
}
}
finally
{
_countMutex.ReleaseMutex();
}
TracerHelper.TraceExit();
return(result);
}
/// <summary>
///
/// </summary>
public DataSet Select(string[] tablesNames, MatchExpression matchExpression, int?limit)
{
string names = "";
for (int i = 0; i < tablesNames.Length; i++)
{
names += tablesNames[i];
if (i != tablesNames.Length - 1)
{
names += ",";
}
}
TracerHelper.TraceEntry(names);
StringBuilder commandText = new StringBuilder();
commandText.Append("SELECT * FROM " + names);
if (matchExpression != null && matchExpression.ClauseCount > 0)
{
commandText.Append(" WHERE ");
}
_selectMutex.WaitOne();
DataSet set = new DataSet();
try
{
using (SQLiteConnection connection = GenerateConnection())
{
using (SQLiteCommand command = new SQLiteCommand(connection))
{
if (matchExpression != null)
{
matchExpression.SetupCommandParameters(command, commandText);
}
if (limit.HasValue)
{
commandText.Append(" LIMIT " + limit.Value);
}
SQLiteDataAdapter adapter = new SQLiteDataAdapter();
command.CommandText = commandText.ToString();
connection.Open();
adapter.SelectCommand = command;
adapter.Fill(set);
}
}
}
finally
{
_selectMutex.ReleaseMutex();
}
TracerHelper.TraceExit();
return(set);
}