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 / 
SQL-Builder-0.03
/ SQL::Builder::FromTable

NAME

SQL::Builder::FromTable - Represents a table used in the SQL FROM clause

SYNOPSIS

This class can generate the following SQL:

        [ONLY] anything [ [AS] anything [anything] ]

or something most likely like:

        table1 AS alias (c1, c2, c3)

SQL::Builder::FromTable is meant to be used as an item in a SQL::Builder::FromList(3), but can easily be used for other purposes.

Here's how to use it:

        my $tbl = SQL::Builder::FromTable->new();
        
        $tbl->table("table1");
        $tbl->alias("t1");

        # table1 AS t1
        print $tbl->sql;

        $tbl->cols(qw(c1 c2 c3));

        # table1 AS t1 (c1, c2, c3)
        print $tbl->sql

DESCRIPTION

This object will likely be used for the composition of SQL::Builder::FromList(3) objects. It is a SQL::Builder::Base(3) subclass and utilizes SQL::Builder::List(3) for maintaining the list of columns

METHODS

new()

See SQL::Builder::Base for new() and set() -- these are inherited

alias([$alias_name])

This will get/set an alias for the table (see table()). This will return the current value if called with no arguments. If an argument is passed, the value is set and the current object is returned

col_container([$obj])

When called with $obj, the value will be set to $obj and return the current object. When called with no arguments, the current value is returned. This object is used to maintain the list of alias columns

cols([@list])

This is a wrapper method to col_container->list() (see SQL::Builder::List::list())

init()

This calls the init() method of the parent class SQL::Builder::Base(3) and sets up the col_container() object with a SQL::Builder::List(3) object. It is called in the constructor new() - see SQL::Builder::Base(3) for new(), set(), and init()

only([1|0])

This toggles the 'ONLY' keyword (see the SYNOPSIS) for possible SQL generation. This keyword is typically used for relations that inherit from other relations; it typically prevents the inheritence of data, but see your DBMS to see what support is provided. Pass a 1 value to turn on the keyword, 0 to turn it off, and no arguments to get the current value. If a value is passed, the current object is returned. This is turned off by default. An undef value enforces the default.

sql()

This is the SQL serialization method. It generates the possible SQL provided in the SYNOPSIS. If only() returns a true value, they SQL "ONLY" keyword is used. If the value of table() has an alias() method, its alias is used if use_table_alias() returns a true or undefined value; when this happens, use_as() is checked. If it returns a true or undefined value, the 'AS' keyword is used. The value of table(), col_container(), and alias() are passed through SQL::Builder::Base::dosql() for serialization. If table() returns an undefined value, an empty string is returned

table([$table])

Gets/sets the current table() value which may be any value. A defined value is required for SQL serialization. When called with an argument, the current value is set and the current object is returned. When no arguments are provided, the current value is returned

use_as([1|0|undef])

Turn on/off the usage of the 'AS' keyword between the relation identifier and its alias. This is turned on by default. Setting a value of 1, 0, or undef sets the current value and returns the current object. When no arguments are provided, the current object is returned. A value of undef enforces default behavior

use_table_alias([1|0|undef])

If table() has an alias() method its value is used unless this method returns false (not including undef, which enforces default behavior) in sql(). Passing a value of 1, 0, or undef sets the current value and returns the current object. Calling without an argument returns the current value. If this method is false (0, not undef), the value of alias() is used in sql() instead of the alias() value returned from table()

children()

Return an SQL::Builder::Iterator to iterate over the values of table(), alias(), and col_container(), in that order

SEE ALSO

SQL:;Builder::List(3) SQL:;Builder::Base(3) SQL:;Builder::FromList(3) SQL:;Builder(3)