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author | Joël Cox <joel@joelcox.nl> | 2011-10-09 18:45:09 +0200 |
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committer | Joël Cox <joel@joelcox.nl> | 2011-10-09 18:45:09 +0200 |
commit | 8ffcb2c8c7ef3da54d7e46c29d502533e413c820 (patch) | |
tree | 1f94e2e81b4d20f2df827b8a84eeda27032161a1 /user_guide_src/source/database/examples.rst | |
parent | f4fb1db458fab52d0493ead52c9ea7e01206eaa7 (diff) | |
parent | 6858c0753a7221796d6a5a1d7fea93cc2f9feb2e (diff) |
Merged develop branch in tutorial.
Diffstat (limited to 'user_guide_src/source/database/examples.rst')
-rw-r--r-- | user_guide_src/source/database/examples.rst | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/user_guide_src/source/database/examples.rst b/user_guide_src/source/database/examples.rst new file mode 100644 index 000000000..d1cd48837 --- /dev/null +++ b/user_guide_src/source/database/examples.rst @@ -0,0 +1,136 @@ +################################## +Database Quick Start: Example Code +################################## + +The following page contains example code showing how the database class +is used. For complete details please read the individual pages +describing each function. + +Initializing the Database Class +=============================== + +The following code loads and initializes the database class based on +your :doc:`configuration <configuration>` settings:: + + $this->load->database(); + +Once loaded the class is ready to be used as described below. + +Note: If all your pages require database access you can connect +automatically. See the :doc:`connecting <connecting>` page for details. + +Standard Query With Multiple Results (Object Version) +===================================================== + +:: + + $query = $this->db->query('SELECT name, title, email FROM my_table'); + + foreach ($query->result() as $row) + { + echo $row->title; + echo $row->name; + echo $row->email; + } + + echo 'Total Results: ' . $query->num_rows(); + +The above result() function returns an array of **objects**. Example: +$row->title + +Standard Query With Multiple Results (Array Version) +==================================================== + +:: + + $query = $this->db->query('SELECT name, title, email FROM my_table'); + + foreach ($query->result_array() as $row) + { + echo $row['title']; + echo $row['name']; + echo $row['email']; + } + +The above result_array() function returns an array of standard array +indexes. Example: $row['title'] + +Testing for Results +=================== + +If you run queries that might **not** produce a result, you are +encouraged to test for a result first using the num_rows() function:: + + $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; + } + } + +Standard Query With Single Result +================================= + +:: + + $query = $this->db->query('SELECT name FROM my_table LIMIT 1'); + $row = $query->row(); + echo $row->name; + +The above row() function returns an **object**. Example: $row->name + +Standard Query With Single Result (Array version) +================================================= + +:: + + $query = $this->db->query('SELECT name FROM my_table LIMIT 1'); + $row = $query->row_array(); + echo $row['name']; + +The above row_array() function returns an **array**. Example: +$row['name'] + +Standard Insert +=============== + +:: + + $sql = "INSERT INTO mytable (title, name) VALUES (".$this->db->escape($title).", ".$this->db->escape($name).")"; + $this->db->query($sql); + echo $this->db->affected_rows(); + +Active Record Query +=================== + +The :doc:`Active Record Pattern <active_record>` gives you a simplified +means of retrieving data:: + + $query = $this->db->get('table_name'); + + foreach ($query->result() as $row) + { + echo $row->title; + } + +The above get() function retrieves all the results from the supplied +table. The :doc:`Active Record <active_record>` class contains a full +compliment of functions for working with data. + +Active Record Insert +==================== + +:: + + $data = array( + 'title' => $title, + 'name' => $name, + 'date' => $date + ); + + $this->db->insert('mytable', $data); // Produces: INSERT INTO mytable (title, name, date) VALUES ('{$title}', '{$name}', '{$date}') + |