public object ExecuteScalar(SqlTemplate sqlTemplate)
{
lock (_dbLocker)
{
SqliteSqlTemplate wrapper = GetSqliteSqlTemplate(sqlTemplate);
string sqlExpression = wrapper.SqlExpression;
using (var conn = new SQLiteConnection(_connectionString))
{
conn.SetPassword(_password);
conn.Open();
using (SQLiteCommand cmd = new SQLiteCommand(sqlExpression, conn))
{
if (wrapper.Params != null && wrapper.Params.Length > 0)
{
cmd.Parameters.AddRange(wrapper.Params.ToArray());
}
return(cmd.ExecuteScalar());
}
}
}
}
private SqliteSqlTemplate GetSqliteSqlTemplate(SqlTemplate sqlTemplate)
{
if (sqlTemplate == null || string.IsNullOrWhiteSpace(sqlTemplate.SqlExpression))
{
// no need to execute value
return(null);
}
SqliteSqlTemplate result = new SqliteSqlTemplate();
result.SqlExpression = sqlTemplate.SqlExpression;
List <SQLiteParameter> newParams = new List <SQLiteParameter>();
if (string.IsNullOrWhiteSpace(sqlTemplate.SqlExpression) || sqlTemplate.Params == null || sqlTemplate.Params.Length == 0)
{
return(result);
}
string sqlExpression = sqlTemplate.SqlExpression;
String[] sqlPieces = sqlExpression.Split('?');
sqlExpression = string.Join("", sqlPieces.Select((d, i) => d + (i == sqlPieces.Length - 1 ? "" : "{" + i + "}")));
for (int i = 0; i < sqlTemplate.Params.Length; i++)
{
object value = sqlTemplate.Params[i];
string name = string.Format("p{0}", i);
SQLiteParameter sQLiteParameter = new SQLiteParameter(name, value);
newParams.Add(sQLiteParameter);
sqlExpression = sqlExpression.Replace("{" + i + "}", "@" + name);
}
result.SqlExpression = sqlExpression;
result.Params = newParams.ToArray();
return(result);
}
