MDB_Common::queryCol()
Описание
Fetch a single column from a result set of a query. The function takes care of doing the query and freeing the results when finished.
Параметр
- string $query
the SQL query
- string $type
if supplied, the type of the column in the result set will be set for fetching
- array $params
if supplied, prepareQuery()/ executeQuery() will be used with this array as execute parameters
- array $param_types
if supplied, the values in $param will automatically set to the passed datatypes
- mixed $colnum
which column to return (integer [column number, starting at 0] or string [column name])
Возвращаемое значение
array - the first row of results as an array indexed from 0 or a MDB_Error, if fail
Throws
Таблица 35-1. Возможные значения PEAR_Error
| Error code | Error message | Reason | Solution |
|---|---|---|---|
| MDB_ERROR_NO_DB_SELECTED | NULL | No database was choosen. | Check the DSN in connect() . |
| MDB_ERROR_TRUNCATED | NULL | The result set contains fewer then two columns | Check the SQL query or choose another query*() function |
| every other error code | Database specific error | Check the database related section of PHP-Manual to detect the reason for this error. In the most cases a misformed SQL statment. Ie. using LIMIT in a SQL-Statment for an Oracle database. |
См. также
query() , limitQuery() , prepareQuery() , executeQuery() , queryRow() , queryOne() , queryAll()
| Пред. | Начало | След. |
| MDB_Common::queryAll() | Уровень выше | MDB_Common::queryOne() |