protected static function get_data_row_update($node_schema, $node_table, $old_data_row_columns, $old_data_row, $new_data_row_columns, $new_data_row, $changed_columns)
{
if (count($changed_columns) == 0) {
throw new exception("empty changed_columns passed");
}
// what columns from new_data_row are different in old_data_row?
// those are the ones to push through the update statement to make the database current
$old_columns = '';
$update_columns = '';
foreach ($changed_columns as $changed_column) {
if (!isset($changed_column['old_col'])) {
$old_columns .= 'NOTDEFINED, ';
} else {
$old_col_value = mssql10::column_value_default($node_schema, $node_table, $changed_column['name'], $changed_column['old_col']);
$old_columns .= $changed_column['name'] . ' = ' . $old_col_value . ', ';
}
$update_col_name = mssql10::get_quoted_column_name($changed_column['name']);
$update_col_value = mssql10::column_value_default($node_schema, $node_table, $changed_column['name'], $changed_column['new_col']);
$update_columns .= $update_col_name . ' = ' . $update_col_value . ', ';
}
// if the computed update_columns expression is < 5 chars, complain
if (strlen($update_columns) < 5) {
var_dump($update_columns);
throw new exception(sprintf("%s.%s update_columns is < 5 chars, unexpected", $node_schema['name'], $node_table['name']));
}
// kill trailing ', '
$update_columns = substr($update_columns, 0, -2);
$old_columns = substr($old_columns, 0, -2);
// use multiline comments here, so when data has newlines they can be preserved, but upgrade scripts don't catch on fire
$sql = sprintf("UPDATE %s.%s SET %s WHERE (%s); /* old values: %s */\n", mssql10::get_quoted_schema_name($node_schema['name']), mssql10::get_quoted_table_name($node_table['name']), $update_columns, dbx::primary_key_expression(dbsteward::$new_database, $node_schema, $node_table, $new_data_row_columns, $new_data_row), $old_columns);
return $sql;
}