diff options
Diffstat (limited to 'user_guide_src/source/database')
| -rw-r--r-- | user_guide_src/source/database/index.rst | 1 | ||||
| -rw-r--r-- | user_guide_src/source/database/query_builder.rst | 178 | ||||
| -rw-r--r-- | user_guide_src/source/database/query_builder_reference.rst | 23 |
3 files changed, 63 insertions, 139 deletions
diff --git a/user_guide_src/source/database/index.rst b/user_guide_src/source/database/index.rst index 4612daf9d..14a871aed 100644 --- a/user_guide_src/source/database/index.rst +++ b/user_guide_src/source/database/index.rst @@ -16,6 +16,7 @@ patterns. The database functions offer clear, simple syntax. Generating Query Results <results> Query Helper Functions <helpers> Query Builder Class <query_builder> + Query Builder API <query_builder_reference> Transactions <transactions> Getting MetaData <metadata> Custom Function Calls <call_function> diff --git a/user_guide_src/source/database/query_builder.rst b/user_guide_src/source/database/query_builder.rst index 3203ff103..701c489d6 100644 --- a/user_guide_src/source/database/query_builder.rst +++ b/user_guide_src/source/database/query_builder.rst @@ -23,14 +23,17 @@ system. :local: :depth: 1 +.. note:: This page describes how to use the Query Builder class. + API reference information is found on the + `Query Builder API <query_builder_reference.html>`_ page. + ************** Selecting Data ************** The following functions allow you to build SQL **SELECT** statements. -$this->db->get() ----------------- +**$this->db->get()** Runs the selection query and returns the result. Can be used by itself to retrieve all records from a table:: @@ -57,11 +60,7 @@ $query, which can be used to show the results:: Please visit the :doc:`result functions <results>` page for a full discussion regarding result generation. -:returns: DB_Result for a successful "read", - TRUE for a successful "write", FALSE if an error - -$this->db->get_compiled_select() --------------------------------- +**$this->db->get_compiled_select()** Compiles the selection query just like **$this->db->get()** but does not *run* the query. This method simply returns the SQL query as a string. @@ -90,10 +89,7 @@ parameter. The reason for this outcome is because the query has not been executed using **$this->db->get()** which resets values or reset directly using **$this->db->reset_query()**. -:returns: The SQL select string - -$this->db->get_where() ----------------------- +**$this->db->get_where()** Identical to the above function except that it permits you to add a "where" clause in the second parameter, instead of using the db->where() @@ -105,11 +101,7 @@ Please read the about the where function below for more information. .. note:: get_where() was formerly known as getwhere(), which has been removed -:returns: DB_Result for a successful "read", - TRUE for a successful "write", FALSE if an error - -$this->db->select() -------------------- +**$this->db->select()** Permits you to write the SELECT portion of your query:: @@ -129,10 +121,7 @@ with backticks. This is useful if you need a compound select statement. $this->db->select('(SELECT SUM(payments.amount) FROM payments WHERE payments.invoice_id=4') AS amount_paid', FALSE); $query = $this->db->get('mytable'); -:returns: The query builder object - -$this->db->select_max() ------------------------ +**$this->db->select_max()** Writes a "SELECT MAX(field)" portion for your query. You can optionally include a second parameter to rename the resulting field. @@ -181,11 +170,7 @@ the resulting field. $this->db->select_sum('age'); $query = $this->db->get('members'); // Produces: SELECT SUM(age) as age FROM members -:returns: The query builder object - - -$this->db->from() ------------------ +**$this->db->from()** Permits you to write the FROM portion of your query:: @@ -196,10 +181,7 @@ Permits you to write the FROM portion of your query:: .. note:: As shown earlier, the FROM portion of your query can be specified in the $this->db->get() function, so use whichever method you prefer. -:returns: The query builder object - -$this->db->join() ------------------ +**$this->db->join()** Permits you to write the JOIN portion of your query:: @@ -223,14 +205,11 @@ outer, and right outer. $this->db->join('comments', 'comments.id = blogs.id', 'left'); // Produces: LEFT JOIN comments ON comments.id = blogs.id -:returns: The query builder object - ************************* Looking for Specific Data ************************* -$this->db->where() ------------------- +**$this->db->where()** This function enables you to set **WHERE** clauses using one of four methods: @@ -306,10 +285,7 @@ instances are joined by OR:: .. note:: or_where() was formerly known as orwhere(), which has been removed. -:returns: The query builder object - -$this->db->where_in() ---------------------- +**$this->db->where_in()** Generates a WHERE field IN ('item', 'item') SQL query joined with AND if appropriate @@ -332,10 +308,7 @@ appropriate $this->db->or_where_in('username', $names); // Produces: OR username IN ('Frank', 'Todd', 'James') -:returns: The query builder object - -$this->db->where_not_in() -------------------------- +**$this->db->where_not_in()** Generates a WHERE field NOT IN ('item', 'item') SQL query joined with AND if appropriate @@ -358,15 +331,11 @@ if appropriate $this->db->or_where_not_in('username', $names); // Produces: OR username NOT IN ('Frank', 'Todd', 'James') -:returns: The query builder object - - ************************ Looking for Similar Data ************************ -$this->db->like() ------------------ +**$this->db->like()** This method enables you to generate **LIKE** clauses, useful for doing searches. @@ -432,10 +401,7 @@ instances are joined by OR:: $this->db->or_not_like('body', 'match'); // WHERE `title` LIKE '%match% OR `body` NOT LIKE '%match%' ESCAPE '!' -:returns: The query builder object - -$this->db->group_by() ---------------------- +**$this->db->group_by()** Permits you to write the GROUP BY portion of your query:: @@ -448,10 +414,7 @@ You can also pass an array of multiple values as well:: .. note:: group_by() was formerly known as groupby(), which has been removed. -:returns: The query builder object - -$this->db->distinct() ---------------------- +**$this->db->distinct()** Adds the "DISTINCT" keyword to a query @@ -460,10 +423,7 @@ Adds the "DISTINCT" keyword to a query $this->db->distinct(); $this->db->get('table'); // Produces: SELECT DISTINCT * FROM table -:returns: The query builder object - -$this->db->having() -------------------- +**$this->db->having()** Permits you to write the HAVING portion of your query. There are 2 possible syntaxes, 1 argument or 2:: @@ -491,14 +451,11 @@ setting it to FALSE. Identical to having(), only separates multiple clauses with "OR". -:returns: The query builder object - **************** Ordering results **************** -$this->db->order_by() ---------------------- +**$this->db->order_by()** Lets you set an ORDER BY clause. @@ -542,14 +499,11 @@ be ignored, unless you specify a numeric seed value. .. note:: Random ordering is not currently supported in Oracle and will default to ASC instead. -:returns: The query builder object - **************************** Limiting or Counting Results **************************** -$this->db->limit() ------------------- +**$this->db->limit()** Lets you limit the number of rows you would like returned by the query:: @@ -561,10 +515,7 @@ The second parameter lets you set a result offset. $this->db->limit(10, 20); // Produces: LIMIT 20, 10 (in MySQL. Other databases have slightly different syntax) -:returns: The query builder object - -$this->db->count_all_results() ------------------------------- +**$this->db->count_all_results()** Permits you to determine the number of rows in a particular Active Record query. Queries will accept Query Builder restrictors such as @@ -575,18 +526,13 @@ where(), or_where(), like(), or_like(), etc. Example:: $this->db->from('my_table'); echo $this->db->count_all_results(); // Produces an integer, like 17 -:returns: Count of all the records returned by a query - -$this->db->count_all() ----------------------- +**$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 $this->db->count_all('my_table'); // Produces an integer, like 25 -:returns: Count of all the records in the specified table - ************** Query grouping ************** @@ -630,14 +576,11 @@ Starts a new group by adding an opening parenthesis to the WHERE clause of the q Ends the current group by adding an closing parenthesis to the WHERE clause of the query. -:returns: The query builder object - ************** Inserting Data ************** -$this->db->insert() -------------------- +**$this->db->insert()** Generates an insert string based on the data you supply, and runs the query. You can either pass an **array** or an **object** to the @@ -674,12 +617,9 @@ object. .. note:: All values are escaped automatically producing safer queries. -:returns: DB_Query on success, FALSE on failure - -$this->db->get_compiled_insert() --------------------------------- +**$this->db->get_compiled_insert()** -Compiles the insertion query just like `$this->db->insert()`_ but does not +Compiles the insertion query just like $this->db->insert() but does not *run* the query. This method simply returns the SQL query as a string. Example:: @@ -696,7 +636,7 @@ Example:: // Produces string: INSERT INTO mytable (title, name, date) VALUES ('My title', 'My name', 'My date') The second parameter enables you to set whether or not the query builder query -will be reset (by default it will be--just like `$this->db->insert()`_):: +will be reset (by default it will be--just like $this->db->insert()):: echo $this->db->set('title', 'My Title')->get_compiled_insert('mytable', FALSE); @@ -714,10 +654,7 @@ using `$this->db->insert()` which resets values or reset directly using .. note:: This method doesn't work for batched inserts. -:returns: The SQL insert string - -$this->db->insert_batch() -------------------------- +**$this->db->insert_batch()** Generates an insert string based on the data you supply, and runs the query. You can either pass an **array** or an **object** to the @@ -744,14 +681,11 @@ associative array of values. .. note:: All values are escaped automatically producing safer queries. -:returns: Count of the number of records inserted on success, FALSE on failure - ************* Updating Data ************* -$this->db->replace() --------------------- +**$this->db->replace()** This method executes a REPLACE statement, which is basically the SQL standard for (optional) DELETE + INSERT, using *PRIMARY* and *UNIQUE* @@ -779,10 +713,7 @@ will be deleted with our new row data replacing it. Usage of the ``set()`` method is also allowed and all fields are automatically escaped, just like with ``insert()``. -:returns: DB_query object on success, FALSE on failure - -$this->db->set() ----------------- +**$this->db->set()** This function enables you to set values for inserts or updates. @@ -840,10 +771,7 @@ Or an object:: $this->db->set($object); $this->db->insert('mytable'); -:returns: The query builder object - -$this->db->update() -------------------- +**$this->db->update()** Generates an update string and runs the query based on the data you supply. You can pass an **array** or an **object** to the function. Here @@ -889,10 +817,7 @@ Or as an array:: You may also use the $this->db->set() function described above when performing updates. -:returns: DB_query object on success, FALSE on failure - -$this->db->update_batch() -------------------------- +**$this->db->update_batch()** Generates an update string based on the data you supply, and runs the query. You can either pass an **array** or an **object** to the function. @@ -933,10 +858,7 @@ array of values, the third parameter is the where key. due to the very nature of how it works. Instead, ``update_batch()`` returns the number of rows affected. -:returns: Count of the number of records affected on success, FALSE on failure - -$this->db->get_compiled_update() --------------------------------- +**$this->db->get_compiled_update()** This works exactly the same way as ``$this->db->get_compiled_insert()`` except that it produces an UPDATE SQL string instead of an INSERT SQL string. @@ -945,14 +867,11 @@ For more information view documentation for `$this->db->get_compiled_insert()`. .. note:: This method doesn't work for batched updates. -:returns: The SQL update string - ************* Deleting Data ************* -$this->db->delete() -------------------- +**$this->db->delete()** Generates a delete SQL string and runs the query. @@ -985,21 +904,14 @@ delete data from more than 1 table. If you want to delete all data from a table, you can use the truncate() function, or empty_table(). -:returns: DB_Query on success, FALSE on failure - -$this->db->empty_table() ------------------------- +**$this->db->empty_table()** Generates a delete SQL string and runs the query.:: $this->db->empty_table('mytable'); // Produces: DELETE FROM mytable -:returns: DB_Query on success, FALSE on failure - - -$this->db->truncate() ---------------------- +**$this->db->truncate()** Generates a truncate SQL string and runs the query. @@ -1018,19 +930,12 @@ Generates a truncate SQL string and runs the query. .. note:: If the TRUNCATE command isn't available, truncate() will execute as "DELETE FROM table". -:returns: DB_Query on success, FALSE on failure - -$this->db->get_compiled_delete() --------------------------------- +**$this->db->get_compiled_delete()** This works exactly the same way as ``$this->db->get_compiled_insert()`` except that it produces a DELETE SQL string instead of an INSERT SQL string. -For more information view documentation for `$this->db->get_compiled_insert()`_. - -:returns: The SQL delete string - - +For more information view documentation for $this->db->get_compiled_insert(). *************** Method Chaining @@ -1074,8 +979,6 @@ This function can be called to stop caching. This function deletes all items from the Query Builder cache. -:returns: void - An example of caching --------------------- @@ -1105,8 +1008,7 @@ Here's a usage example:: Resetting Query Builder *********************** -$this->db->reset_query() ------------------------- +**$this->db->reset_query()** Resetting Query Builder allows you to start fresh with your query without executing it first using a method like $this->db->get() or $this->db->insert(). @@ -1135,6 +1037,4 @@ run the query:: .. note:: Double calls to ``get_compiled_select()`` while you're using the Query Builder Caching functionality and NOT resetting your queries will results in the cache being merged twice. That in turn will - i.e. if you're caching a ``select()`` - select the same field twice. - -:returns: void + i.e. if you're caching a ``select()`` - select the same field twice.
\ No newline at end of file diff --git a/user_guide_src/source/database/query_builder_reference.rst b/user_guide_src/source/database/query_builder_reference.rst new file mode 100644 index 000000000..f20a1e70d --- /dev/null +++ b/user_guide_src/source/database/query_builder_reference.rst @@ -0,0 +1,23 @@ +################# +Query Builder API +################# + +.. note:: This page provides a complete API reference for the Query Builder + class. For information on how to use the class, see the + `Query Builder Class <query_builder.html>`_ page. + +*************** +Class Reference +*************** + +.. class:: CI_DB_query_builder + + .. method:: count_all_results($table = '') + + :param string $table: Table name to query + :returns: Number of rows in the query result + :rtype: int + + Generates a platform-specific query string that counts + all records returned by an Query Builder query. + |