List <List <string> > GetKeysInternal(ISqlTableSource tableSource)
{
//TODO: needed mechanism to define unique indexes. Currently only primary key is used
// only from tables we can get keys
if (!(tableSource is SqlTable))
{
return(null);
}
var keys = tableSource.GetKeys(false);
if (keys == null || keys.Count == 0)
{
return(null);
}
var fields = keys.Select(GetUnderlayingField)
.Where(f => f != null)
.Select(f => f.Name).ToList();
if (fields.Count != keys.Count)
{
return(null);
}
var knownKeys = new List <List <string> >();
knownKeys.Add(fields);
return(knownKeys);
}
private void AddConditions(SqlWhereClause where, ISqlTableSource table)
{
var keys = table.GetKeys(true);
if (keys == null)
{
return;
}
foreach (var key in keys.OfType <SqlField>())
{
var maxValue = GetMaxValue(key.DataType);
if (maxValue == null)
{
continue;
}
var cond = new SqlSearchCondition();
cond = cond.Expr(key).IsNull.Or;
if (maxValue is string)
{
cond.Expr(key).GreaterOrEqual.Expr(new SqlValue(maxValue));
}
else
{
cond.Expr(key).LessOrEqual.Expr(new SqlValue(maxValue));
}
where.ConcatSearchCondition(cond);
// only one field is enough
break;
}
}