Query Results
There are several ways to generate query results:
result()
This function returns the query result as an array of objects, or FALSE 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;
}
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;
}
}
result_array()
This function returns the query result as a pure array, or FALSE on failure. 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'];
}
row()
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;
}
If you want a specific row returned you can submit the row number as a digit in the first parameter:
$row = $query->row(5);
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'];
}
If you want a specific row returned you can submit the row number as a digit in the first parameter:
$row = $query->row_array(5);
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()
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')
Query Result Helpers
The following functions provide useful information when dealing with query results.
$query->num_rows()
The number of rows returned by the query. Note: $query is the variable that the query was assigned to:
$query = $this->db->query('SELECT * FROM my_table');
echo $query->num_rows();
$query->num_fields()
The number of FIELDS 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();
$this->db->insert_id()
The insert ID number when performing database inserts.
$this->db->affected_rows()
Displays the number of affected rows, when doing "write" type queries (insert, update, etc.).
Note: In MySQL "DELETE FROM TABLE" returns 0 affected rows. The database class has a small hack that allows it to return the correct number of affected rows. By default this hack is enabled but it can be turned off in the database driver file.$this->db->version()
Outputs the database version you are running:
echo $this->db->version();