diff options
Diffstat (limited to 'user_guide_src/source/database/results.rst')
| -rw-r--r-- | user_guide_src/source/database/results.rst | 53 |
1 files changed, 49 insertions, 4 deletions
diff --git a/user_guide_src/source/database/results.rst b/user_guide_src/source/database/results.rst index 865345762..e0a87a851 100644 --- a/user_guide_src/source/database/results.rst +++ b/user_guide_src/source/database/results.rst @@ -99,7 +99,7 @@ to instantiate the row with:: echo $row->reverse_name(); // or methods defined on the 'User' class row_array() -============ +=========== Identical to the above row() function, except it returns an array. Example:: @@ -136,12 +136,39 @@ parameter: | **$row = $query->next_row('array')** | **$row = $query->previous_row('array')** +.. note:: all the functions above will load the whole result into memory (prefetching) use unbuffered_row() for processing large result sets. + +unbuffered_row() +================ + +This method returns a single result row without prefetching the whole +result in memory as ``row()`` does. If your query has more than one row, +it returns the current row and moves the internal data pointer ahead. + +:: + + $query = $this->db->query("YOUR QUERY"); + + while ($row = $query->unbuffered_row()) + { + echo $row->title; + echo $row->name; + echo $row->body; + } + +You can optionally pass 'object' (default) or 'array' in order to specify +the returned value's type:: + + $query->unbuffered_row(); // object + $query->unbuffered_row('object'); // object + $query->unbuffered_row('array'); // associative array + *********************** Result Helper Functions *********************** $query->num_rows() -=================== +================== The number of rows returned by the query. Note: In this example, $query is the variable that the query result object is assigned to:: @@ -157,7 +184,7 @@ is the variable that the query result object is assigned to:: resulting array in order to achieve the same functionality. $query->num_fields() -===================== +==================== The number of FIELDS (columns) returned by the query. Make sure to call the function using your query result object:: @@ -167,7 +194,7 @@ the function using your query result object:: echo $query->num_fields(); $query->free_result() -====================== +===================== It frees the memory associated with the result and deletes the result resource ID. Normally PHP frees its memory automatically at the end of @@ -189,3 +216,21 @@ Example:: $row = $query2->row(); echo $row->name; $query2->free_result(); // The $query2 result object will no longer be available + +data_seek() +=========== + +This method sets the internal pointer for the next result row to be +fetched. It is only useful in combination with ``unbuffered_row()``. + +It accepts a positive integer value, which defaults to 0 and returns +TRUE on success or FALSE on failure. + +:: + + $query = $this->db->query('SELECT `field_name` FROM `table_name`'); + $query->data_seek(5); // Skip the first 5 rows + $row = $query->unbuffered_row(); + +.. note:: Not all database drivers support this feature and will return FALSE. + Most notably - you won't be able to use it with PDO.
\ No newline at end of file |