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author | dchill42 <dchill42@gmail.com> | 2012-07-23 16:53:47 +0200 |
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committer | dchill42 <dchill42@gmail.com> | 2012-07-23 16:53:47 +0200 |
commit | c5079de78e5141330c07e990811ef15e998e95aa (patch) | |
tree | 0f39d8c4fc7614246fc185810bfeaa7fad88a33a /user_guide_src/source/database/helpers.rst | |
parent | 00fcb545109d4e61bc14e403ec828749c34a54b3 (diff) | |
parent | ede49ba66b127535f3430e20aac72ceed2c4611a (diff) |
Merge branch develop of github.com:/EllisLab/CodeIgniter into session
Diffstat (limited to 'user_guide_src/source/database/helpers.rst')
-rw-r--r-- | user_guide_src/source/database/helpers.rst | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/user_guide_src/source/database/helpers.rst b/user_guide_src/source/database/helpers.rst new file mode 100644 index 000000000..e8a5ac801 --- /dev/null +++ b/user_guide_src/source/database/helpers.rst @@ -0,0 +1,98 @@ +###################### +Query Helper Functions +###################### + +$this->db->insert_id() +======================= + +The insert ID number when performing database inserts. + +.. note:: If using the PDO driver with PostgreSQL, or using the Interbase + driver, 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. |