/**
* Returns the column descriptions for a table.
*
* The return value is an associative array keyed by the column name,
* as returned by the RDBMS.
*
* The value of each array element is an associative array
* with the following keys:
*
* SCHEMA_NAME => string; name of schema
* TABLE_NAME => string;
* COLUMN_NAME => string; column name
* COLUMN_POSITION => number; ordinal position of column in table
* DATA_TYPE => string; SQL datatype name of column
* DEFAULT => string; default expression of column, null if none
* NULLABLE => boolean; true if column can have nulls
* LENGTH => number; length of CHAR/VARCHAR
* SCALE => number; scale of NUMERIC/DECIMAL
* PRECISION => number; precision of NUMERIC/DECIMAL
* UNSIGNED => boolean; unsigned property of an integer type
* PRIMARY => boolean; true if column is part of the primary key
* PRIMARY_POSITION => integer; position of column in primary key
* IDENTITY => integer; true if column is auto-generated with unique values
*
* @todo Discover integer unsigned property.
*
* @param string $tableName
* @param string $schemaName OPTIONAL
* @return array
*/
public function describeTable($tableName, $schemaName = null)
{
$desc = parent::describeTable($tableName, $schemaName);
$tableName = strtolower($tableName);
$schemaName = strtolower($schemaName);
$sql = "select distinct table_name\n from information_schema.key_column_usage\n where referenced_table_name = ? ";
$bind = array();
$bind[] = $tableName;
if ($schemaName != null) {
$bind[] = $schemaName;
$sql .= " and constraint_schema = ? ";
}
$dependentTables = $this->fetchAll($sql, $bind);
$sql = "select column_name,\n referenced_table_name as 'table_name_reference',\n referenced_table_schema as 'schema_name_reference',\n referenced_column_name as 'column_name_reference'\n from information_schema.key_column_usage\n where referenced_table_name is not null\n and table_name = ?";
$bind = array();
$bind[] = $tableName;
/* if ($schemaName != null) {
$bind[]= $schemaName;
$sql.= " table_schema = ? ";
} */
$referenceMap = $this->fetchAll($sql, $bind);
$desc[$this->foldCase('reference_map')] = $referenceMap;
$desc[$this->foldCase('dependent_tables')] = $dependentTables;
return $desc;
}
/**
* Get Existing Columns
*
* @return array
*/
protected function _getExistingColumns()
{
return $this->_db->describeTable($this->_model->table());
}
