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authorJoël Cox <joel@joelcox.nl>2011-10-09 18:45:09 +0200
committerJoël Cox <joel@joelcox.nl>2011-10-09 18:45:09 +0200
commit8ffcb2c8c7ef3da54d7e46c29d502533e413c820 (patch)
tree1f94e2e81b4d20f2df827b8a84eeda27032161a1 /user_guide_src/source/database/helpers.rst
parentf4fb1db458fab52d0493ead52c9ea7e01206eaa7 (diff)
parent6858c0753a7221796d6a5a1d7fea93cc2f9feb2e (diff)
Merged develop branch in tutorial.
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+######################
+Query Helper Functions
+######################
+
+$this->db->insert_id()
+=======================
+
+The insert ID number when performing database inserts.
+
+.. note:: If using the PDO driver with PostgreSQL, this function requires
+ a $name parameter, which specifies the appropriate sequence to check
+ for the insert id.
+
+$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->count_all();
+========================
+
+Permits you to determine the number of rows in a particular table.
+Submit the table name in the first parameter. Example::
+
+ echo $this->db->count_all('my_table');
+
+ // Produces an integer, like 25
+
+$this->db->platform()
+=====================
+
+Outputs the database platform you are running (MySQL, MS SQL, Postgres,
+etc...)::
+
+ echo $this->db->platform();
+
+$this->db->version()
+====================
+
+Outputs the database version you are running::
+
+ echo $this->db->version();
+
+$this->db->last_query();
+=========================
+
+Returns the last query that was run (the query string, not the result).
+Example::
+
+ $str = $this->db->last_query();
+
+ // Produces: SELECT * FROM sometable....
+
+The following two functions help simplify the process of writing
+database INSERTs and UPDATEs.
+
+$this->db->insert_string();
+============================
+
+This function simplifies the process of writing database inserts. It
+returns a correctly formatted SQL insert string. Example::
+
+ $data = array('name' => $name, 'email' => $email, 'url' => $url);
+
+ $str = $this->db->insert_string('table_name', $data);
+
+The first parameter is the table name, the second is an associative
+array with the data to be inserted. The above example produces::
+
+ INSERT INTO table_name (name, email, url) VALUES ('Rick', 'rick@example.com', 'example.com')
+
+.. note:: Values are automatically escaped, producing safer queries.
+
+$this->db->update_string();
+============================
+
+This function simplifies the process of writing database updates. It
+returns a correctly formatted SQL update string. Example::
+
+ $data = array('name' => $name, 'email' => $email, 'url' => $url);
+
+ $where = "author_id = 1 AND status = 'active'";
+
+ $str = $this->db->update_string('table_name', $data, $where);
+
+The first parameter is the table name, the second is an associative
+array with the data to be updated, and the third parameter is the
+"where" clause. The above example produces::
+
+ UPDATE table_name SET name = 'Rick', email = 'rick@example.com', url = 'example.com' WHERE author_id = 1 AND status = 'active'
+
+.. note:: Values are automatically escaped, producing safer queries.