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oceanbase/src/sql/engine/expr/ob_expr_database.cpp
oceanbase-admin cea7de1475 init push
2021-05-31 22:56:52 +08:00

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/**
* 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.
*/
#include "sql/engine/expr/ob_expr_database.h"
#include "sql/session/ob_sql_session_info.h"
#include "sql/engine/ob_exec_context.h"
using namespace oceanbase::common;
namespace oceanbase {
namespace sql {
ObExprDatabase::ObExprDatabase(ObIAllocator& alloc) : ObStringExprOperator(alloc, T_FUN_SYS_DATABASE, N_DATABASE, 0)
{}
ObExprDatabase::~ObExprDatabase()
{}
int ObExprDatabase::calc_result_type0(ObExprResType& type, ObExprTypeCtx& type_ctx) const
{
UNUSED(type_ctx);
type.set_varchar();
type.set_default_collation_type();
type.set_collation_level(CS_LEVEL_SYSCONST);
type.set_length(OB_MAX_DATABASE_NAME_LENGTH);
return OB_SUCCESS;
}
int ObExprDatabase::calc_result0(ObObj& result, ObExprCtx& expr_ctx) const
{
int ret = OB_SUCCESS;
const ObSQLSessionInfo* session_info = NULL;
if (OB_ISNULL(session_info = expr_ctx.my_session_)) {
ret = OB_ERR_UNEXPECTED;
SQL_ENG_LOG(WARN, "session info is null");
} else {
const ObString database_name = session_info->get_database_name();
if (database_name.empty()) {
result.set_null();
} else {
result.set_varchar(database_name);
result.set_collation(result_type_);
}
}
return ret;
}
int ObExprDatabase::eval_database(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum)
{
int ret = OB_SUCCESS;
UNUSED(expr);
const ObBasicSessionInfo* session_info = NULL;
if (OB_ISNULL(session_info = ctx.exec_ctx_.get_my_session())) {
ret = OB_ERR_UNEXPECTED;
SQL_ENG_LOG(WARN, "session info is null", K(ret));
} else {
const ObString database_name = session_info->get_database_name();
if (database_name.empty()) {
expr_datum.set_null();
} else {
expr_datum.set_string(database_name);
}
}
return ret;
}
int ObExprDatabase::cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const
{
UNUSED(raw_expr);
UNUSED(op_cg_ctx);
rt_expr.eval_func_ = ObExprDatabase::eval_database;
return OB_SUCCESS;
}
} // namespace sql
} // namespace oceanbase