PHP Index::setColumns方法代码示例

 /**
  * Adds extra indices for reverse foreign keys
  * This is required for MySQL databases,
  * and is called from Database::doFinalInitialization()
  */
 public function addExtraIndices()
 {
     /**
      * A collection of indexed columns. The keys is the column name
      * (concatenated with a comma in the case of multi-col index), the value is
      * an array with the names of the indexes that index these columns. We use
      * it to determine which additional indexes must be created for foreign
      * keys. It could also be used to detect duplicate indexes, but this is not
      * implemented yet.
      * @var array
      */
     $_indices = array();
     $this->collectIndexedColumns('PRIMARY', $this->getPrimaryKey(), $_indices);
     $_tableIndices = array_merge($this->getIndices(), $this->getUnices());
     foreach ($_tableIndices as $_index) {
         $this->collectIndexedColumns($_index->getName(), $_index->getColumns(), $_indices);
     }
     // we're determining which tables have foreign keys that point to this table,
     // since MySQL needs an index on any column that is referenced by another table
     // (yep, MySQL _is_ a PITA)
     $counter = 0;
     foreach ($this->getReferrers() as $foreignKey) {
         $referencedColumns = $foreignKey->getForeignColumnObjects();
         $referencedColumnsHash = $this->getColumnList($referencedColumns);
         if (!array_key_exists($referencedColumnsHash, $_indices)) {
             // no matching index defined in the schema, so we have to create one
             $index = new Index();
             $index->setName(sprintf('I_referenced_%s_%s', $foreignKey->getName(), ++$counter));
             $index->setColumns($referencedColumns);
             $index->resetColumnSize();
             $this->addIndex($index);
             // Add this new index to our collection, otherwise we might add it again (bug #725)
             $this->collectIndexedColumns($index->getName(), $referencedColumns, $_indices);
         }
     }
     // we're adding indices for this table foreign keys
     foreach ($this->getForeignKeys() as $foreignKey) {
         $localColumns = $foreignKey->getLocalColumnObjects();
         $localColumnsHash = $this->getColumnList($localColumns);
         if (!array_key_exists($localColumnsHash, $_indices)) {
             // no matching index defined in the schema, so we have to create one. MySQL needs indices on any columns that serve as foreign keys. these are not auto-created prior to 4.1.2
             $index = new Index();
             $index->setName(substr_replace($foreignKey->getName(), 'FI_', strrpos($foreignKey->getName(), 'FK_'), 3));
             $index->setColumns($localColumns);
             $index->resetColumnSize();
             $this->addIndex($index);
             $this->collectIndexedColumns($index->getName(), $localColumns, $_indices);
         }
     }
 }

 /**
  * <p>Adds extra indices for multi-part primary key columns.</p>
  *
  * <p>For databases like MySQL, values in a where clause much
  * match key part order from the left to right.  So, in the key
  * definition <code>PRIMARY KEY (FOO_ID, BAR_ID)</code>,
  * <code>FOO_ID</code> <i>must</i> be the first element used in
  * the <code>where</code> clause of the SQL query used against
  * this table for the primary key index to be used.  This feature
  * could cause problems under MySQL with heavily indexed tables,
  * as MySQL currently only supports 16 indices per table (i.e. it
  * might cause too many indices to be created).</p>
  *
  * <p>See <a href="http://www.mysql.com/doc/E/X/EXPLAIN.html">the
  * manual</a> for a better description of why heavy indexing is
  * useful for quickly searchable database tables.</p>
  */
 private function doHeavyIndexing()
 {
     if (self::DEBUG) {
         print "doHeavyIndex() called on table " . $this->name . "\n";
     }
     $pk = $this->getPrimaryKey();
     $size = count($pk);
     // We start at an offset of 1 because the entire column
     // list is generally implicitly indexed by the fact that
     // it's a primary key.
     for ($i = 1; $i < $size; $i++) {
         $idx = new Index();
         $idx->setColumns(array_slice($pk, $i, $size));
         $this->addIndex($idx);
     }
 }