NAME
DB::Object::SQLite - DB Object SQLite Driver
SYNOPSIS
use DB::Object;
my $dbh = DB::Object->connect({
driver => 'SQLite',
conf_file => 'db-settings.json',
database => 'webstore',
host => 'localhost',
login => 'store-admin',
schema => 'auth',
debug => 3,
}) || bailout( "Unable to connect to sql server on host localhost: ", DB::Object->error );
# Legacy regular query
my $sth = $dbh->prepare( "SELECT login,name FROM login WHERE login='jack'" ) ||
die( $dbh->errstr() );
$sth->execute() || die( $sth->errstr() );
my $ref = $sth->fetchrow_hashref();
$sth->finish();
# Get a list of databases;
my @databases = $dbh->databases;
# Doesn't exist? Create it:
my $dbh2 = $dbh->create_db( 'webstore' );
# Load some sql into it
my $rv = $dbh2->do( $sql ) || die( $dbh->error );
# Check a table exists
$dbh->table_exists( 'customers' ) || die( "Cannot find the customers table!\n" );
# Get list of tables, as array reference:
my $tables = $dbh->tables;
my $cust = $dbh->customers || die( "Cannot get customers object." );
$cust->where( email => 'john@example.org' );
my $str = $cust->delete->as_string;
# Becomes: DELETE FROM customers WHERE email='john\@example.org'
# Do some insert with transaction
$dbh->begin_work;
# Making some other inserts and updates here...
my $cust_sth_ins = $cust->insert(
first_name => 'Paul',
last_name => 'Goldman',
email => 'paul@example.org',
active => 0,
) || do
{
# Rollback everything since the begin_work
$dbh->rollback;
die( "Error while create query to add data to table customers: " . $cust->error );
};
$result = $cust_sth_ins->as_string;
# INSERT INTO customers (first_name, last_name, email, active) VALUES('Paul', 'Goldman', 'paul\@example.org', '0')
$dbh->commit;
# Get the last used insert id
my $id = $dbh->last_insert_id();
$cust->where( email => 'john@example.org' );
$cust->order( 'last_name' );
$cust->having( email => qr/\@example/ );
$cust->limit( 10 );
my $cust_sth_sel = $cust->select || die( "An error occurred while creating a query to select data frm table customers: " . $cust->error );
# Becomes:
# SELECT id, first_name, last_name, email, created, modified, active, created::ABSTIME::INTEGER AS created_unixtime, modified::ABSTIME::INTEGER AS modified_unixtime, CONCAT(first_name, ' ', last_name) AS name FROM customers WHERE email='john\@example.org' HAVING email ~ '\@example' ORDER BY last_name LIMIT 10
$cust->reset;
$cust->where( email => 'john@example.org' );
my $cust_sth_upd = $cust->update( active => 0 )
# Would become:
# UPDATE ONLY customers SET active='0' WHERE email='john\@example.org'
# Lets' dump the result of our query
# First to STDERR
$login->where( "login='jack'" );
$login->select->dump();
# Now dump the result to a file
$login->select->dump( "my_file.txt" );
VERSION
v1.1.3
DESCRIPTION
This package inherits from DB::Object, so any method not here, but there you can use.
DB::Object::SQLite is a SQL API much alike DBD::SQLite. So why use a private module instead of using that great DBD::SQLite package?
At first, I started to inherit from DBI
to conform to perlmod
perl manual page and to general perl coding guidlines. It became very quickly a real hassle. Barely impossible to inherit, difficulty to handle error, too much dependent from an API that change its behaviour with new versions. In short, I wanted a better, more accurate control over the SQL connection.
So, DB::Object::SQLite acts as a convenient, modifiable wrapper that provide the programmer with an intuitive, user-friendly and hassle free interface.
CONSTRUCTOR
new
Create a new instance of DB::Object::SQLite. Nothing much to say.
connect
Same as "connect" in DB::Object, only specific to SQLite.
METHODS
alias
This is inherited from "alias" in DB::Object
as_string
This is inherited from "as_string" in DB::Object
avoid
This is inherited from "avoid" in DB::Object
attribute
Sets or get the value of database connection parameters.
If only one argument is provided, returns its value. If multiple arguments in a form of pair => value are provided, it sets the corresponding database parameters.
The authorised parameters are:
ActiveKids
Is read-only.
AutoCommit
Can be changed.
AutoInactiveDestroy
Can be changed.
CachedKids
Is read-only.
ChildHandles
Is read-only.
ChopBlanks
Can be changed.
CursorName
Is read-only.
Driver
Is read-only.
ErrCount
Can be changed.
Executed
Is read-only.
FetchHashKeyName
Can be changed.
HandleError
Can be changed.
HandleSetErr
Can be changed.
InactiveDestroy
Can be changed.
Kids
Is read-only.
NAME
Is read-only.
NULLABLE
Is read-only.
NUM_OF_FIELDS
Is read-only.
NUM_OF_PARAMS
Is read-only.
Name
Is read-only.
PRECISION
Is read-only.
PrintError
Can be changed.
PrintWarn
Can be changed.
Profile
Can be changed.
RaiseError
Can be changed.
RowCacheSize
Is read-only.
RowsInCache
Is read-only.
SCALE
Is read-only.
ShowErrorStatement
Can be changed.
Statement
Is read-only.
TYPE
Is read-only.
Taint
Can be changed.
TaintIn
Can be changed.
TaintOut
Can be changed.
TraceLevel
Can be changed.
Type
Can be changed.
Username
Is read-only.
Warn
Can be changed.
sqlite_allow_multiple_statements
Can be changed.
sqlite_see_if_its_a_number
Can be changed.
sqlite_unicode
Can be changed.
sqlite_unprepared_statements
Is read-only.
sqlite_use_immediate_transaction
Can be changed.
sqlite_version
Is read-only.
available_drivers
Return the list of available drivers.
This is an inherited method from "available_drivers" in DB::Object
begin_work
Mark the beginning of a transaction.
Any arguments provided are passed along to "begin_work" in DBD::SQLite
bind
This is an inherited method from "bind" in DB::Object
cache
This is an inherited method from "cache" in DB::Object
can_update_delete_limit
Returns the boolean value for the SQLite compiled option ENABLE_UPDATE_DELETE_LIMIT
by calling "has_compile_option"
check_driver
This is an inherited method from "check_driver" in DB::Object
commit
Make any change to the database irreversible.
This must be used only after having called "begin_work"
Any arguments provided are passed along to "commit" in DBD::SQLite
compile_options
Returns the cached list of SQLite compiled options. The cached file is in the file sql_sqlite_compile_options.cfg
in the sytem directory.
connect
Same as "connect" in DB::Object, only specific to SQLite.
It sets sqlite_unicode
to a true value in the connection parameters returned by "_connection_params2hash"
copy
This is an inherited method from "copy" in DB::Object
create_table
This is an inherited method from "create_table" in DB::Object
data_sources
This is an inherited method from "data_sources" in DB::Object
data_type
This is an inherited method from "data_type" in DB::Object
database
This is an inherited method from "database" in DB::Object
database_file
Returns the file path to the database file.
databases
Returns a list of databases, which in SQLite, means a list of opened sqlite database files.
datatype_dict
Returns an hash reference of each data type with their equivalent constant
, regular expression (re
), constant name
and type
name.
Each data type is an hash with the following properties for each type: constant
, name
, re
, type
delete
This is an inherited method from "database" in DB::Object
disconnect
This is an inherited method from "disconnect" in DB::Object
do
This is an inherited method from "do" in DB::Object
enhance
This is an inherited method from "enhance" in DB::Object
func
Provided with a table name and a function name and this will call DB::SQLite passing it the table name and the function name.
It returns the value received from the function call.
get_sql_type
Provided with a data type as a string and this returns a SQLite constant suitable to be passed to "bind_param" in DBI
having
A convenient wrapper to "having" in DB::Object::SQLite::Query
has_compile_option
Provided with a compile option (the character case is irrelevant) and this will check if it exists or not.
last_insert_id
lock
This is an unsupported feature in SQLIte
on_conflict
See "on_conflict" in DB::Object::SQLite::Tables
pragma
This is still a work in progress.
replace
Just like for the INSERT query, "replace" takes one optional argument representing a DB::Object::SQLite::Statement SELECT object or a list of field-value pairs.
If a SELECT statement is provided, it will be used to construct a query of the type of REPLACE INTO mytable SELECT FROM other_table
Otherwise the query will be REPLACE INTO mytable (fields) VALUES(values)
In scalar context, it execute the query and in list context it simply returns the statement handler.
register_function
This takes an hash reference of parameters and will register a new function by calling "sql_function_register" in DBD::SQLite
Possible options are:
code
Anonymous code to be executed when the function is called.
func
This is an hash reference representing registry of functions. The value for each key is the option hash reference.
flags
An array reference of flags
name
The function name
remove_function
Provided with a function name and this will remove it.
It returns false if there is no function, or returns the options hash reference originally set for the function removed.
returning
A convenient wrapper to "returning" in DB::Object::Postgres::Query
rollback
Will roll back any changes made to the database since the last transaction point marked with "begin_work"
sql_function_register
Provided with an hash reference of options and this will register a sql function by calling "sqlite_create_function" in DBD::SQLite
Possible options are:
argc
The function arguments
code
Anonymous perl code to be executed when the function is called
flags
An array reference of flags. Those flags are joined with
|
and "eval" in perlfunc'edname
The function name
stat
Provided with an hash or hash reference of parameters and this will call "sqlite_status" in DBD::SQLite and get the hash reference of values returned.
If the option reset is set, then this will call "sqlite_status" in DBD::SQLite passing it 0 to reset it instead.
If the option type is specified, this will return the equivalent property from the stat hash reference returned by "sqlite_status" in DBD::SQLite, otherwise, it will return the hash in list context and the hash reference of stat properties in scalar context.
table_info
Provided with a table name and this will retrieve the table information as an hash reference.
Otherwise, if nothing can be found, it returns an empty hash reference.
It takes no optional parameters.
Information retrieved are:
name
The table name
type
The object type, which may be one of:
table
,view
,materialized view
,special
,foreign table
tables
Connects to the database and finds out the list of all available tables.
Returns undef or empty list in scalar or list context respectively if no table found.
Otherwise, it returns the list of table in list context or a reference of it in scalar context.
tables_info
Provided with a database or using by default the current database and this will issue a query to get an array reference of all tables.
It returns the array reference.
trace
Trace is unsupported on SQLite.
unlock
Unlock is unsupported on SQLite.
variables
Variables are unsupported on SQLite.
version
This returns the, possibly cached, SQLite server version as a version object.
_check_connect_param
This returns an hash reference of connection parameters.
If there is no "database_file" currently set, it will use the property uri.
The database is taken from the property database, or derived from the last path segment of the uri.
The database file is made absolute and is et as the database_file property
The database is name, if not set, is derived from the base path of the database_file
The host property is set to localhost
and port property to 0
It returns the hash reference of parameters thus processed.
_check_default_option
Provided with an hash or hash reference of options and this will check it and set some default value.
The only default property this sets is sqlite_unicode
to true.
It returns the hash reference of options.
_connection_options
Provided with an hash reference of parameters and this will check them and returns an hash reference of options who name start with sqlite_
_connection_parameters
Provided with an hash or hash reference of connection parameters and this will extra all the properties that start with sqlite_/
and add them to an array of core properties: db login passwd host port driver database server opt uri debug
It returns those properties as an array reference.
_dbi_connect
This calls "_dbi_connect" in DB::Connect and do more driver specific processing.
It will register all the functions set in the global hash reference $PRIVATE_FUNCTIONS
which is a function name to code reference pairs. For each of those function, they will be added by calling "sql_function_register"
It returns the database handler object (DBD::Object::SQLite)
_dsn
Using the "database_file" set and this will issue a connection to the SQLite database file.
If the file does not exist or is not writable, this will return an error, otherwise this will return the string representing the dsn, which are connection parameters separated by ;
_parse_timestamp
Provided a string and this will parse it to return a DateTime object.
SQLITE FUNCTIONS AVAILABLE
ceiling
This is a sql function to be registered automatically upon connection to the SQLite database file.
It leverages "ceil" in POSIX
concat
This returns the arguments provided concatenated as a string.
curdate
Returns a string representing the year, month and date separated by a -
This is computed using DateTime
curtime
Returns a string representing the hours, minutes and seconds separated by a :
This is computed using DateTime
dayname
Based on a datetime that is parsed using "_parse_timestamp", this returns the day name of the week, such as Monday
dayofmonth
Based on a datetime that is parsed using "_parse_timestamp", this returns the day of the month, such as 17.
dayofweek
Based on a datetime that is parsed using "_parse_timestamp", this returns the day of the week as a number from 1 to 7 with 1 being Monday
dayofyear
Based on a datetime that is parsed using "_parse_timestamp", this returns the day of the year, such as a number from 1 to 365, or possibly 366 depending on the year.
distance_miles
Provided with an original latitude, longitude and a target latitude and longitude and this will calculate the distance between the 2.
See the source StackOverflow post on which this function is based.
from_days
Calculate the number of days since January 1st of year 0 and returns a DateTime object.
from_unixtime
Provided with a unix timestamp, and this will return a datetime string such as YYYY-mm-dd HH:MM:SS
hour
Provided with a date time, and this will parse it and return the hour.
lcase
Provided with a string and this returns its lower case value.
left
Provided with a string and an integer n
and this will return a substring capturing the nth first characters.
locate
This essentially does the same as "index" in perlfunc
log10
Provided with a number and this returns its logarithm base 10.
minute
Provided with a date time, and this will parse it and return the minutes.
month
Provided with a date time, and this will parse it and return the month.
monthname
Provided with a date time, and this will parse it and return the month name.
number_format
Provided with a number, a thousand separator, a decimal separator and a decimal precision and this will format the number accordingly and return it as a string.
power
Provided with a number and a power, and this will return the number powered
quarter
Provided with a date time, and this will parse it and return the quarter.
query_object
Set or gets the SQLite query object (DB::Object::SQLite::Query) used to process and format queries.
rand
This takes no argument and simply returns a random number using "rand" in perlfunc
regexp
Provided with a regular expression and the string to test, and this will test the regular expression and return true if it matches or false otherwise.
replace
Provided with a string, some term to replace and a replacement string and this will do a perl substitution and return the resulting string.
right
Provided with a string and an integer n and this will return the nth right most characters.
second
Provided with a date time, and this will parse it and return the seconds.
space
Provided with an integer and this will return as much spaces.
sprintf
This behaves like "sprintf" in perlfunc and provided with a template and some arguments, it will return a formatted string.
to_days
Provided with a date time, and this will return the number of days since January 1st of year 0.
ucase
This returns the string provided with all its characters in upper case.
unix_timestamp
Provided with a date time and this will returns its unix timestamp representation.
week
Provided with a date time, and this will parse it and return the week.
weekday
Provided with a date time, and this will parse it and return the day of the week.
year
Provided with a date time, and this will parse it and return the day of the year.
SEE ALSO
AUTHOR
Jacques Deguest <jack@deguest.jp>
COPYRIGHT & LICENSE
Copyright (c) 2019-2021 DEGUEST Pte. Ltd.
You can use, copy, modify and redistribute this package and associated files under the same terms as Perl itself.