Files
oceanbase/src/sql/engine/expr/ob_expr_database.cpp
2023-04-27 11:11:24 +00:00

73 lines
2.0 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.
*/
#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, NOT_VALID_FOR_GENERATED_COL)
{
}
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::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;
}
}
}