git.m6w6.name Git - mdref/mdref-pq-gateway/blob - hasRelation.md

   1 # bool pq\Gateway\Table::hasRelation(string $name[, string $table = NULL])
   2
   3 Check whether a relation to another table exists with the specified name.
   4 See pq\Gateway\Table\Relations
   5
   6 > ***NOTE:***
   7   The relation name is the column name of the foreign key with the column name of the referenced column cut off the end.
   8
   9 ## Params:
  10
  11 * string $name
  12   The name of the relation.
  13 * Optional string $table = NULL
  14   The bare table name, if the relation has another name (e.g. because of multiple foreign keys to the same table).
  15
  16 ## Returns:
  17
  18 * bool, whether the specified relation exists.
  19
  20 ## Example:
  21
  22         <?php
  23
  24         use pq\Gateway\Table;
  25
  26         $conn = new pq\Connection;
  27         $conn->exec("
  28                 drop table if exists account cascade;
  29                 drop table if exists email cascade;
  30                 drop table if exists reftable cascade;
  31
  32                 create table account (
  33                         id serial primary key
  34                 );
  35
  36                 create table email (
  37                         id serial primary key,
  38                         account_id integer references account(id),
  39                         email text
  40                 );
  41
  42                 create table reftable (
  43                         id serial primary key,
  44                         my_account integer references account(id),
  45                         account_id integer references account(id),
  46                         second_account_id integer references account(id),
  47                         email integer references email(id)
  48                 );
  49         ");
  50
  51         $fgn_table = new Table("reftable");
  52         var_dump($fgn_table->hasRelation("my_account"));
  53
  54         ?>
  55
  56 Yields:
  57
  58         TRUE