diff options
Diffstat (limited to 'user_guide_src/source/database/results.rst')
| -rw-r--r-- | user_guide_src/source/database/results.rst | 96 |
1 files changed, 79 insertions, 17 deletions
diff --git a/user_guide_src/source/database/results.rst b/user_guide_src/source/database/results.rst index a85b89bef..4f93c794d 100644 --- a/user_guide_src/source/database/results.rst +++ b/user_guide_src/source/database/results.rst @@ -11,14 +11,31 @@ This function returns the query result as an array of **objects**, or **an empty array** on failure. Typically you'll use this in a foreach loop, like this:: - $query = $this->db->query("YOUR QUERY"); foreach ($query->result() as $row) { echo $row->title; echo $row->name; echo $row->body; } + $query = $this->db->query("YOUR QUERY"); + + foreach ($query->result() as $row) + { + echo $row->title; + echo $row->name; + echo $row->body; + } The above function is an alias of result_object(). If you run queries that might **not** produce a result, you are encouraged to test the result first:: - $query = $this->db->query("YOUR QUERY"); if ($query->num_rows() > 0) { foreach ($query->result() as $row) { echo $row->title; echo $row->name; echo $row->body; } } + $query = $this->db->query("YOUR QUERY"); + + if ($query->num_rows() > 0) + { + foreach ($query->result() as $row) + { + echo $row->title; + echo $row->name; + echo $row->body; + } + } You can also pass a string to result() which represents a class to instantiate for each result object (note: this class must be loaded) @@ -40,7 +57,14 @@ This function returns the query result as a pure array, or an empty array when no result is produced. Typically you'll use this in a foreach loop, like this:: - $query = $this->db->query("YOUR QUERY"); foreach ($query->result_array() as $row) { echo $row['title']; echo $row['name']; echo $row['body']; } + $query = $this->db->query("YOUR QUERY"); + + foreach ($query->result_array() as $row) + { + echo $row['title']; + echo $row['name']; + echo $row['body']; + } row() ===== @@ -49,7 +73,16 @@ This function returns a single result row. If your query has more than one row, it returns only the first row. The result is returned as an **object**. Here's a usage example:: - $query = $this->db->query("YOUR QUERY"); if ($query->num_rows() > 0) { $row = $query->row(); echo $row->title; echo $row->name; echo $row->body; } + $query = $this->db->query("YOUR QUERY"); + + if ($query->num_rows() > 0) + { + $row = $query->row(); + + echo $row->title; + echo $row->name; + echo $row->body; + } If you want a specific row returned you can submit the row number as a digit in the first parameter:: @@ -59,7 +92,11 @@ digit in the first parameter:: You can also add a second String parameter, which is the name of a class to instantiate the row with:: - $query = $this->db->query("SELECT * FROM users LIMIT 1;"); $query->row(0, 'User') echo $row->name; // call attributes echo $row->reverse_name(); // or methods defined on the 'User' class + $query = $this->db->query("SELECT * FROM users LIMIT 1;"); + $query->row(0, 'User'); + + echo $row->name; // call attributes + echo $row->reverse_name(); // or methods defined on the 'User' class row_array() ============ @@ -67,7 +104,16 @@ row_array() Identical to the above row() function, except it returns an array. Example:: - $query = $this->db->query("YOUR QUERY"); if ($query->num_rows() > 0) { $row = $query->row_array(); echo $row['title']; echo $row['name']; echo $row['body']; } + $query = $this->db->query("YOUR QUERY"); + + if ($query->num_rows() > 0) + { + $row = $query->row_array(); + + echo $row['title']; + echo $row['name']; + echo $row['body']; + } If you want a specific row returned you can submit the row number as a digit in the first parameter:: @@ -77,18 +123,18 @@ digit in the first parameter:: In addition, you can walk forward/backwards/first/last through your results using these variations: -**$row = $query->first_row()** - **$row = $query->last_row()** - **$row = $query->next_row()** - **$row = $query->previous_row()** + | **$row = $query->first_row()** + | **$row = $query->last_row()** + | **$row = $query->next_row()** + | **$row = $query->previous_row()** By default they return an object unless you put the word "array" in the parameter: -**$row = $query->first_row('array')** - **$row = $query->last_row('array')** - **$row = $query->next_row('array')** - **$row = $query->previous_row('array')** + | **$row = $query->first_row('array')** + | **$row = $query->last_row('array')** + | **$row = $query->next_row('array')** + | **$row = $query->previous_row('array')** *********************** Result Helper Functions @@ -100,7 +146,9 @@ $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:: - $query = $this->db->query('SELECT * FROM my_table'); echo $query->num_rows(); + $query = $this->db->query('SELECT * FROM my_table'); + + echo $query->num_rows(); $query->num_fields() ===================== @@ -108,7 +156,9 @@ $query->num_fields() The number of FIELDS (columns) returned by the query. Make sure to call the function using your query result object:: - $query = $this->db->query('SELECT * FROM my_table'); echo $query->num_fields(); + $query = $this->db->query('SELECT * FROM my_table'); + + echo $query->num_fields(); $query->free_result() ====================== @@ -120,5 +170,17 @@ particular script you might want to free the result after each query result has been generated in order to cut down on memory consumptions. Example:: - $query = $this->db->query('SELECT title FROM my_table'); foreach ($query->result() as $row) { echo $row->title; } $query->free_result(); // The $query result object will no longer be available $query2 = $this->db->query('SELECT name FROM some_table'); $row = $query2->row(); echo $row->name; $query2->free_result(); // The $query2 result object will no longer be available + $query = $this->db->query('SELECT title FROM my_table'); + + foreach ($query->result() as $row) + { + echo $row->title; + } + $query->free_result(); // The $query result object will no longer be available + + $query2 = $this->db->query('SELECT name FROM some_table'); + + $row = $query2->row(); + echo $row->name; + $query2->free_result();// The $query2 result object will no longer be available |