114 lines
3.5 KiB
C++
114 lines
3.5 KiB
C++
/**
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* Copyright (c) 2021 OceanBase
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* OceanBase CE is licensed under Mulan PubL v2.
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* You can use this software according to the terms and conditions of the Mulan PubL v2.
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* You may obtain a copy of Mulan PubL v2 at:
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* http://license.coscl.org.cn/MulanPubL-2.0
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* THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
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* EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
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* MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
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* See the Mulan PubL v2 for more details.
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*/
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#define USING_LOG_PREFIX SQL_ENG
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#include "ob_expr_right.h"
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#include <string.h>
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#include "lib/charset/ob_charset.h"
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#include "share/object/ob_obj_cast.h"
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#include "objit/common/ob_item_type.h"
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#include "sql/session/ob_sql_session_info.h"
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using namespace oceanbase::common;
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using namespace oceanbase::sql;
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namespace oceanbase
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{
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namespace sql
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{
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ObExprRight::ObExprRight(ObIAllocator &alloc) :
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ObStringExprOperator(alloc, T_FUN_SYS_RIGHT, "right", 2)
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{
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}
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ObExprRight::~ObExprRight()
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{
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}
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int ObExprRight::calc_result_type2(ObExprResType &type, ObExprResType &type1,
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ObExprResType &type2,ObExprTypeCtx &type_ctx) const
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{
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int ret = OB_SUCCESS;
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type2.set_calc_type(ObIntType);
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type_ctx.set_cast_mode(type_ctx.get_cast_mode() | CM_STRING_INTEGER_TRUNC);
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type.set_varchar();
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type.set_length(type1.get_length());
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OZ(aggregate_charsets_for_string_result(type, &type1, 1, type_ctx.get_coll_type()));
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OX(type1.set_calc_type(ObVarcharType));
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OX(type1.set_calc_collation_type(type.get_collation_type()));
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return ret;
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}
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int do_right(const ObString &input_value, const ObCollationType &cs_type,
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const int64_t length, ObString &res_str)
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{
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int ret = OB_SUCCESS;
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int64_t char_len = (int64_t)(ObCharset::strlen_char(cs_type,
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input_value.ptr(),
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input_value.length()));
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int64_t pos = char_len - length;
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if (length < 0) {
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res_str.reset();
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//return empty string
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} else if (pos <= 0) {
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res_str = input_value;
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} else {
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int32_t offset = (int32_t)
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ObCharset::charpos(cs_type, input_value.ptr(), input_value.length(), pos);
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if (offset <= input_value.length()) {
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res_str.assign_ptr(input_value.ptr() + offset, input_value.length() - offset);
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}
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}
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return ret;
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}
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int calc_right_expr(const ObExpr &expr, ObEvalCtx &ctx, ObDatum &res_datum)
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{
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int ret = OB_SUCCESS;
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// right(s, n)
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ObDatum *s_datum = NULL;
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ObDatum *n_datum = NULL;
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if (OB_FAIL(expr.args_[0]->eval(ctx, s_datum)) ||
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OB_FAIL(expr.args_[1]->eval(ctx, n_datum))) {
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LOG_WARN("eval arg failed", K(ret), KP(s_datum), KP(n_datum));
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} else if (s_datum->is_null() || n_datum->is_null()) {
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res_datum.set_null();
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} else {
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ObString res_str;
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const ObCollationType arg_cs_type = expr.args_[0]->datum_meta_.cs_type_;
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if(OB_FAIL(do_right(s_datum->get_string(), arg_cs_type, n_datum->get_int(), res_str))) {
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LOG_WARN("failed to calculate right expression", K(ret));
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} else {
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if (res_str.empty() && is_oracle_mode()) {
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res_datum.set_null();
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} else {
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res_datum.set_string(res_str);
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}
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}
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}
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return ret;
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}
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int ObExprRight::cg_expr(ObExprCGCtx &expr_cg_ctx, const ObRawExpr &raw_expr,
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ObExpr &rt_expr) const
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{
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int ret = OB_SUCCESS;
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UNUSED(expr_cg_ctx);
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UNUSED(raw_expr);
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rt_expr.eval_func_ = calc_right_expr;
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return ret;
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}
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}// namespace sql
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}// namespace oceanbase
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