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App-Framework-1.02
River stage one • 1 direct dependent • 1 total dependent
/ App::Framework::Feature::Sql

NAME

Sql - MySql interface

SYNOPSIS

use App::Framework '+Sql' ;

DESCRIPTION

Provides a simplified interface to MySQL via DBI.

DOCUMENTATION TO BE COMPLETED

FIELDS

The following fields should be defined either in the call to 'new()', as part of a 'set()' call, or called by their accessor method (which is the same name as the field):

host - MySql host [default=localhost]
database - Database name (required)
table - Table name
user - User name
password - Password
trace - Sql debug trace level [default=0]
trace_file - If specified, output trace information to file (default=STDOUT)
sql_vars - Default HASH used to store 'prepare' values
prepare - Create one or more queries

CONSTRUCTOR

new([%args])

Create a new Sql object.

The %args are specified as they would be in the set method, for example:

'mmap_handler' => $mmap_handler

The full list of possible arguments are :

'fields'	=> Either ARRAY list of valid field names, or HASH of field names with default values

CLASS METHODS

init_class([%args])

Initialises the Sql object class variables.

OBJECT DATA METHODS

set(%args)

Set one or more settable parameter.

The %args are specified as a hash, for example

set('mmap_handler' => $mmap_handler)

Sets field values. Field values are expressed as part of the HASH (i.e. normal field => value pairs).

OBJECT METHODS

sql([%args])

Returns the sql object. If %args are specified they are used to set the "FIELDS"

Sql([%args])

Alias to "sql"

prepare($prepare_href)

Use HASH ref to create 1 or more STHs

trace(@args)

Change trace level

trace_file(@args)

Change trace file

connect(%args)

Connects to database. Either uses pre-set values for user/password/database, or can use optionally specified args

disconnect()

Disconnect from database (if connected)

sth_create($name, $spec)

Prepare a named SQL query & store it for later execution by query_sth()

Name is saved as $name. Certain names are 'special':

ins*	- Create an 'insert' type command
upd*	- Create an 'update' type command
sel*	- Create a 'select' type command
check* - Create a 'select' type command

The $spec is either a SCALAR or HASH ref

If $spec is a SCALAR then it is in the form of sql. Note, when the query is executed the values (if required) must be specified.

If $spec is a HASH ref then it can contain the following fields:

'cmd'	=> Command type: 'insert', 'update', 'select'
'vars'	=> ARRAY ref list of variable names (used for 'insert', 'update')
'vals'	=> Provides values to be used in the query (no extra values need to be specified). HASH ref or ARRAY ref. 
           HASH ref - the hash is used to look up the values using the 'vars' names
           ARRAY ref - list of values (or refs to values)
           NOTE: If insufficient values are provided for the query, then the remaining values must be specified in the query call
'sql'  	=> Sql string.
		   NOTE: Depending on the command type, if the command is not specified then a default will be prepended to this string.
'table'	=> Overrides the object table setting for this query
'limit'	=> Sets the limit on the number of results
'group'	=> Specify group by string
'where'	=> Where clause. String or HASH ref.
		   String - specify sql for where clause (can omit 'WHERE' prefix)
		   HASH ref - specify where clause as HASH:  
				'sql' => Used to specify more complicated where clauses (e.g. '`pid`=? AND `channel`=?')
				'vars'	=> ARRAY ref list of variable names (used for 'where'). If no 'sql' is specified, then the where clause
						   is created by ANDing the vars together (e.g. [qw/pid channel/] gives '`pid`=? AND `channel`=?')
				'vals'	=> Provides values to be used in the query (no extra values need to be specified). HASH ref or ARRAY ref.

EXAMPLES

The following are all (almost) equivalent:

$sql->sth_create('check',  {
				'table'	=> '$table',
				'limit'	=> 1,
				'where'	=> {
					'sql' => '`pid`=? AND `channel`=?',
					'vars'	=> [qw/pid channel/],
					'vals'	=> \%sql_vars
				}) ;

$sql->sth_create('check2',  {
				'table'	=> '$table',
				'limit'	=> 1,
				'where'	=> '`pid`=? AND `channel`=?',# need to pass in extra params to query method
				}}) ;

$sql->sth_create('check3',  "SELECT * FROM `$table` WHERE `pid`=? AND `channel`=? LIMIT 1") ;

$sql->sth_create('select',  "WHERE `pid`=? AND `channel`=? LIMIT 1") ;

They are then used as:

$sql->sth_query('check') ; # already given it's parameters
$sql->sth_query('check2', $pid, $channel) ;
$sql->sth_query('check3', $pid, $channel) ;
$sql->sth_query('select', $pid, $channel) ;
sth_query($name, [@vals])

Use a pre-prepared named sql query to return results. If the query has already been given a set of values, then use them; otherwise use the values specified in this call (or append the values to an insufficient list of values given when the sth was created)

sth_query_all($name, [@vals])

Use a pre-prepared named sql query to return results. Return all results in array.

query($query [, @vals])

Query database

query_all($query)

Query database - return array of complete results, each entry is a hash ref

do($sql)

Do sql command

do_sql_text($sql_text)

Process the SQL text, split it into one or more SQL command, then execute each of them

next([$name])

Returns hash ref to next row (as a result of query). Uses prepared STH name $name (as created by sth_create method), or default name (as created by query method)

tables()

Returns list of tables for this database

datestr_to_sqldate($datestr)

Convert standard date string (d-MMM-YYYY) or (d/M/YY) to SQL based date (YYYY-MM-DD)

sqldate_to_date($sql_date)

Convert SQL based date (YYYY-MM-DD) to standard date string (d-MMM-YYYY)

sqldate_to_datemanip($sql_date)

Convert SQL based date (YYYY-MM-DD) to a date string suitable for Date::Manip (d/M/YYYY)

sql_from_data($name)

NOTE: Only works when feature is registered with an application

Execute the (possible sequence of) command(s) stored in a named __DATA__ area in the application.

_sql_cmd($name)

Convert $name into a sql command if possible

_sql_setvars($context, $spec, $vars_href)

Set/add variables into the $vars_href HASH driven by the specification $spec (which may be a sql string or a HASH specification). Creates the variables in the namespace defined by the $context string (which is usually the lookup string into the %CMD_SQL table)

_sql_expand_vars($vars_href)

Expand all the variables in the HASH ref

_sql_expand_arrays($vars_href)

Expand all the array variables in the HASH ref

_sql_expand_array($arr, $vars_href)

Expand the named array

_sth_record($name)

Returns the saved sth information looked up from $name; returns undef otherwise

_sth_record_sth($name)

Returns the saved sth looked up from $name; returns undef otherwise

_set_trace($dbh, $trace, $trace_file)

Update trace level

DIAGNOSTICS

Setting the debug flag to level 1 prints out (to STDOUT) some debug messages, setting it to level 2 prints out more verbose messages.

AUTHOR

Steve Price <sdprice at cpan.org>

BUGS

None that I know of!

NOTE: To avoid the common "Mysql server gone away" problem, everywhere that I get the database connection handle, I actually call the connect() method to ensure the connection is working.