MDB_Common::getCol()
Synopsis
array &getCol
(
string $query
,
string $type
= null
,
array
$params = array()
,
array $param_types
= null
,
mixed
$colnum = 0
)
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.
Parameter
-
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])
Return value
array - the first row of results as an array
indexed from 0 or a MDB_Error, if fail
Throws
| Error code | Error message | Reason | Solution |
|---|---|---|---|
| MDB_ERROR_INVALID | NULL | SQL statement for preparing is not valid. | See the prepareQuery() documentation, if you want to use a SQL statemt using wildcards. |
| MDB_ERROR_NEED_MORE_DATA | NULL | To less data for filling the prepared SQL statement. |
Check the number of wild cards given in the SQL statement
prepareQuery()
. Check the count of
entries in the array for $params. The count
of entries have to be equal to the number of wild cards.
|
| MDB_ERROR_NO_DB_SELECTED | NULL | No database was chosen. | Check the DSN in connect() . |
| MDB_ERROR_TRUNCATED | NULL | The result set contains fewer then two columns | Check the SQL query or choose another get*() function |
| every other error code | Database specific error | Check the database related section of PHP-Руководство to detect the reason for this error. In the most cases a misformed SQL statement. Ie. using LIMIT in a SQL-Statement for an Oracle database. |
Замечание
This function can not be called statically.
See
query() , limitQuery() , prepareQuery() , executeQuery() , getRow() , getOne() , getAssoc()