compile method

@override String compile(Set<String> trampoline, { bool includeTableName = false, String? preamble, bool withFields = true, String? fromQuery, })

Implementation

@override
String compile(Set<String> trampoline,
    {bool includeTableName = false,
    String? preamble,
    bool withFields = true,
    String? fromQuery}) {
  // One table MAY appear multiple times in a query.
  if (!canCompile(trampoline)) {
    //return null;
    //throw Exception('One table appear multiple times in a query');
    return '';
  }

  includeTableName = includeTableName || _joins.isNotEmpty;
  var b = StringBuffer(preamble ?? 'SELECT');
  b.write(' ');
  List<String> f;

  var compiledJoins = <JoinBuilder, String?>{};

  //if (fields == null) {
  if (fields.isEmpty) {
    f = ['*'];
  } else {
    f = List<String>.from(fields.map((s) {
      String? ss = includeTableName ? '$tableName.$s' : s;
      if (expressions.containsKey(s)) {
        ss = '( ${expressions[s]} )';
        //ss = expressions[s];
      }
      var cast = casts[s];
      if (cast != null) ss = 'CAST ($ss AS $cast)';
      if (aliases.containsKey(s)) {
        if (cast != null) {
          ss = '($ss) AS ${aliases[s]}';
        } else {
          ss = '$ss AS ${aliases[s]}';
        }
        if (expressions.containsKey(s)) {
          // ss = '($ss)';
        }
      } else if (expressions.containsKey(s)) {
        if (cast != null) {
          ss = '($ss) AS $s';
          // ss = '(($ss) AS $s)';
        } else {
          ss = '$ss AS $s';
          // ss = '($ss AS $s)';
        }
      }
      return ss;
    }));
    for (var j in _joins) {
      var c = compiledJoins[j] = j.compile(trampoline);
      //if (c != null) {
      if (c != '') {
        var additional = j.additionalFields.map(j.nameFor).toList();
        f.addAll(additional);
      } else {
        // If compilation failed, fill in NULL placeholders.
        for (var i = 0; i < j.additionalFields.length; i++) {
          f.add('NULL');
        }
      }
    }
  }
  if (withFields) b.write(f.join(', '));
  fromQuery ??= tableName;
  b.write(' FROM $fromQuery');

  // No joins if it's not a select.
  if (preamble == null) {
    if (_crossJoin != null) b.write(' CROSS JOIN $_crossJoin');
    for (var join in _joins) {
      var c = compiledJoins[join];
      if (c != null) b.write(' $c');
    }
  }

  var whereClause =
      where?.compile(tableName: includeTableName ? tableName : null);
  if (whereClause?.isNotEmpty == true) {
    b.write(' WHERE $whereClause');
  }
  if (_groupBy != null) b.write(' GROUP BY $_groupBy');
  var orderByClause = _orderBy.map((order) => order.compile()).join(', ');
  if (orderByClause.isNotEmpty) {
    b.write(' ORDER BY $orderByClause');
  }
  if (_limit != null) b.write(' LIMIT $_limit');
  if (_offset != null) b.write(' OFFSET $_offset');
  return b.toString();
}