/**
 * Copyright (c) 2021 OceanBase
 * OceanBase CE is licensed under Mulan PubL v2.
 * You can use this software according to the terms and conditions of the Mulan PubL v2.
 * You may obtain a copy of Mulan PubL v2 at:
 *          http://license.coscl.org.cn/MulanPubL-2.0
 * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
 * EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
 * MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
 * See the Mulan PubL v2 for more details.
 */

#ifndef _OB_SQL_EXPR_COALESCE_H_
#define _OB_SQL_EXPR_COALESCE_H_

#include "sql/engine/expr/ob_expr_operator.h"

namespace oceanbase {
namespace sql {
class ObExprCoalesce : public ObExprOperator {
public:
  explicit ObExprCoalesce(common::ObIAllocator& alloc);
  virtual ~ObExprCoalesce();
  virtual int calc_result_typeN(
      ObExprResType& type, ObExprResType* types_stack, int64_t param_num, common::ObExprTypeCtx& type_ctx) const;
  virtual int calc_resultN(
      common::ObObj& result, const common::ObObj* objs_stack, int64_t param_num, common::ObExprCtx& expr_ctx) const;
  virtual int cg_expr(ObExprCGCtx& expr_ct_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
  static int calc(common::ObObj& result, const common::ObObj* objs_stack, int64_t param_num,
      const ObExprResType& expected_type, common::ObCastCtx& cast_ctx);

private:
  DISALLOW_COPY_AND_ASSIGN(ObExprCoalesce);
};
}  // namespace sql
}  // namespace oceanbase
#endif /* _OB_SQL_EXPR_COALESCE_H_ */