/**
* Compiles Fragment_SQL fragments into an SQL string.
*
* @param \Glue\DB\Fragment_SQL $fragment
*
* @return string
*/
protected function compile_sql(\Glue\DB\Fragment_SQL $fragment)
{
// Get data from fragment :
$template = $fragment->sql();
$replacements = $fragment->replacements();
// Split template according to inline string litterals and identifiers :
$matches = preg_split("/('(?:''|[^'])*'|`(?:``|[^`])*`)/", $template, -1, PREG_SPLIT_DELIM_CAPTURE);
// Loop over matches and generate SQL :
$cn = $this;
$sql = '';
for ($i = 0; $i < count($matches); $i++) {
// Get string :
$part = $matches[$i];
// Tell apart delimiters from pieces :
if ($i % 2 === 0) {
// In-between string, we must make replacements :
$sql .= preg_replace_callback('/[?!]/', function ($matches) use($cn, &$replacements) {
// Get next replacement :
$replacement = array_shift($replacements);
// Replacement is a fragment ?
if ($replacement instanceof \Glue\DB\Fragment) {
return $cn->compile($replacement);
} else {
// Tell appart value from identifier replacements :
if ($matches[0] === '?') {
// Value :
return $cn->quote_value($replacement);
} else {
// Identifier :
if (is_array($replacement)) {
$replacement = array_map(array($cn, 'quote_identifier'), $replacement);
return implode('.', $replacement);
} else {
return $cn->quote_identifier($replacement);
}
}
}
}, $part);
} else {
// Delimiter string, we must quote it according to current connection conventions :
if ($part[0] === "'") {
// String litteral :
$sql .= $this->quote(\Glue\DB\DB::unquote($part));
} else {
// Identifier :
$sql .= $this->quote_identifier(\Glue\DB\DB::unquote_identifier($part));
}
}
}
return $sql;
}
