/// <summary>
/// performs a single update operation on a table
/// </summary>
/// <param name="tableName">name of the table to perform the updates within</param>
/// <param name="values">the columns to update and the values to update them to</param>
/// <param name="conjunction">defines how the predicates should be joined in the query</param>
/// <param name="predicates">the predicates for the update operation, all of which must be true for the operation to succeed</param>
public void Update(string tableName, List <DBPredicate> values, List <DBPredicate> predicates, DBConjunction conjunction = DBConjunction.AND)
{
lock ( m_databaseLock )
{
_VerifyConnection();
try
{
m_sqlConnection.Open();
SQLiteCommandBuilder builder = new SQLiteCommandBuilder();
using (SQLiteCommand command = m_sqlConnection.CreateCommand())
{
command.CommandText = $"UPDATE {builder.QuoteIdentifier(tableName)} SET(";
_AppendPredicates(command, values, ",");
command.CommandText += ") WHERE(";
_AppendPredicates(command, predicates, conjunction.ToString());
command.CommandText += ");";
Debug.WriteLine("Executing update query: " + command.CommandText);
command.ExecuteNonQuery();
}
m_sqlConnection.Close();
}
catch (Exception crap)
{
m_sqlConnection.Close();
throw crap;
}
}
}
/// <summary>
/// Selects all rows from a table where all of a list of predicates are true
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="tableName">name of the table to select from</param>
/// <param name="predicates">list of predicates, all of which must evaluate to true</param>
/// <param name="predicateConjunction">how the list of predicates should be joined when performing the query</param>
/// <returns>a list of data containers, each containing one row of the results, or null if there were no results</returns>
public List <T> Select <T>(string tableName, List <DBPredicate> predicates, DBDataContainerCreator <T> dataContainerCreator, DBConjunction predicateConjunction) where T : DBDataContainer <T>
{
lock ( m_databaseLock )
{
_VerifyConnection();
List <T> queryResults = new List <T>();
try
{
m_sqlConnection.Open();
using (SQLiteCommand command = m_sqlConnection.CreateCommand())
{
SQLiteCommandBuilder builder = new SQLiteCommandBuilder();
command.CommandText = $"SELECT * FROM {builder.QuoteIdentifier(tableName)} WHERE ";
_AppendPredicates(command, predicates, predicateConjunction.ToString());
command.CommandText += ";";
queryResults = _ExecuteSelectCommand <T>(command, dataContainerCreator);
}
}
catch (Exception crap)
{
m_sqlConnection.Close();
throw crap;
}
finally
{
m_sqlConnection.Close();
}
return(queryResults);
}
}
