/// <summary>
/// Gets a cql UPDATE statement based on the current state
/// </summary>
public string GetUpdate(Expression expression, out object[] values, int?ttl, DateTimeOffset?timestamp,
MapperFactory mapperFactory)
{
Visit(expression);
var query = new StringBuilder(DefaultQueryStringCapacity);
var parameters = new List <object>();
query.Append("UPDATE ");
query.Append(GetEscapedTableName());
if (ttl != null || timestamp != null)
{
query.Append(" USING ");
}
if (ttl != null)
{
query.Append("TTL ?");
parameters.Add(ttl.Value);
if (timestamp != null)
{
query.Append(" AND ");
}
}
if (timestamp != null)
{
query.Append("TIMESTAMP ? ");
parameters.Add((timestamp.Value - CqlQueryTools.UnixStart).Ticks / 10);
}
query.Append(" SET ");
var setStatements = new List <string>();
foreach (var projection in _projections)
{
var column = projection.Item1;
var columnName = Escape(column.ColumnName);
var value = mapperFactory.AdaptValue(_pocoData, column, projection.Item2);
string operation;
switch (projection.Item3)
{
case ExpressionType.AddAssign:
operation = " = " + columnName + " + ?";
parameters.Add(value);
break;
case ExpressionType.PreIncrementAssign:
operation = " = ? + " + columnName;
parameters.Add(value);
break;
case ExpressionType.SubtractAssign:
operation = " = " + columnName + " - ?";
parameters.Add(value);
break;
case ExpressionType.Increment:
//Counter
operation = " = " + columnName + " + ?";
parameters.Add(projection.Item2);
break;
case ExpressionType.Decrement:
//Counter
operation = " = " + columnName + " - ?";
parameters.Add(projection.Item2);
break;
default:
operation = " = ?";
parameters.Add(value);
break;
}
setStatements.Add(columnName + operation);
}
if (setStatements.Count == 0)
{
throw new CqlArgumentException("Nothing to update");
}
query.Append(string.Join(", ", setStatements));
GenerateConditions(_where, "WHERE", query, parameters, expression);
GenerateConditions(_ifClause, "IF", query, parameters, expression);
values = parameters.ToArray();
return(query.ToString());
}