Цитата:
Изначально опубликовано ushastik
Простейший вопрос не могу решить - как определить, пустой ли результат селекта.
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Евгений
Differences between X++ and SQL in handling aggregate functions
Whenever the where clause of a query does not match any rows, the SQL standard stipulates, that one row is to be returned, in which count-columns return the value ‘0’ (zero), and all other aggregated columns return SQL value null.
Since Axapta does not support the concept of null values, a slightly different approach is taken:
Whenever a row returned from the SQL database contains a null value from an aggregated column (e.g. SUM(f)), the row is skipped, and no rows are returned to the user.
However, if count, which does not return null values, is the only aggregate function used, one row is returned (as stated in the SQL standard) with ‘0’ (zero) value(s).
If null, on the other hand, is returned from an ordinary column, an error exception is thrown with the message
“Unsupported null value selected from the database.”.
Although Axapta does not support null values in the DBMS sense, the different data types each have a specific value that is treated like a null value in certain circumstances.
Цитата:
Изначально опубликовано ushastik
- как же жить тогда и не застрелиться ?
Евгений
Может, это поможет Вам жить?
