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oceanbase/src/sql/engine/expr/ob_expr_reverse.h
wangzelin.wzl 93a1074b0c patch 4.0
2022-10-24 17:57:12 +08:00

88 lines
3.1 KiB
C++

/**
* 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 OCEANBASE_SQL_EXPR_FUNC_REVERSE_
#define OCEANBASE_SQL_EXPR_FUNC_REVERSE_
#include "sql/engine/expr/ob_expr_operator.h"
namespace oceanbase
{
namespace sql
{
class ObExprReverse : public ObStringExprOperator
{
public:
explicit ObExprReverse(common::ObIAllocator &alloc);
virtual ~ObExprReverse();
virtual int calc_result_type1(ObExprResType &type,
ObExprResType &type1,
common::ObExprTypeCtx &type_ctx) const;
virtual int cg_expr(ObExprCGCtx &expr_cg_ctx, const ObRawExpr &raw_expr,
ObExpr &rt_expr) const;
static int do_reverse(const common::ObString &input_str,
const common::ObCollationType &cs_type,
common::ObIAllocator *allocator,
common::ObString &res_str);
private:
DISALLOW_COPY_AND_ASSIGN(ObExprReverse);
};
inline int ObExprReverse::calc_result_type1(ObExprResType &type,
ObExprResType &type1,
common::ObExprTypeCtx &type_ctx) const
{
UNUSED(type_ctx);
int ret = OB_SUCCESS;
type1.set_calc_type(common::ObVarcharType);
type1.set_calc_collation_type(type1.get_collation_type());
if (lib::is_mysql_mode()) {
if (ObTextType == type1.get_type()
|| ObMediumTextType == type1.get_type()
|| ObLongTextType == type1.get_type()) {
type.set_type(ObLongTextType);
const int32_t mbmaxlen = 4;
const int32_t default_text_length =
ObAccuracy::DDL_DEFAULT_ACCURACY[ObLongTextType].get_length() / mbmaxlen;
type.set_length(default_text_length);
} else {
type.set_varchar();
if (ObTinyTextType == type1.get_type()) {
type.set_length(OB_MAX_TINYTEXT_LENGTH - 1);
} else {
type.set_length(type1.get_length());
}
}
ret = aggregate_charsets_for_string_result(type, &type1, 1, type_ctx.get_coll_type());
} else {
if (ob_is_character_type(type1.get_type(), type1.get_collation_type())
|| ob_is_varbinary_or_binary(type1.get_type(), type1.get_collation_type())
|| ObNullType == type1.get_type()) {
type.set_type(type1.get_type());
type.set_collation_type(type1.get_collation_type());
type.set_collation_level(type1.get_collation_level());
type.set_length(type1.get_length());
} else {
ret = OB_ERR_INVALID_TYPE_FOR_OP;
LOG_USER_ERROR(OB_ERR_INVALID_TYPE_FOR_OP,
ob_obj_type_str(ObCharType),
ob_obj_type_str(type1.get_type()));
}
}
return ret;
}
}
}
#endif /* OCEANBASE_SQL_EXPR_FUNC_REVERSE_ */