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Fix mysql rollup duplicate columns wrong result

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This commit is contained in:
hezuojiao
2023-05-22 12:52:53 +00:00
committed by ob-robot
parent e40c4256b3
commit bb740d865c
1 changed files with 41 additions and 2 deletions
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43
src/sql/code_generator/ob_static_engine_cg.cpp
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@ -3504,13 +3504,37 @@ int ObStaticEngineCG::generate_spec(ObLogGroupBy &op, ObMergeGroupBySpec &spec,
OB_LOG(WARN, "fail to init_duplicate_rollup_expr", K(ret));
}
bool is_duplicate = false;
const bool is_oracle_mode = lib::is_oracle_mode();
// In the two different modes of mysql and oracle, the behavior of rollup duplicate columns
// is different. For example, when there is one row [1] in t1, in oracle mode
// select c1 from t1 group by rollup(c1, c1);
// +------+
// | c1 |
// +------+
// | 1 |
// | 1 |
// | NULL |
// +------+
// In mysql mode
// select c1 from t1 group by c1, c1 with rollup;
// +------+
// | c1 |
// +------+
// | 1 |
// | NULL |
// | NULL |
// +------+
// So we need to distinguish between two modes when initializing `is_duplicate_rollup_expr_`
// array. For oracle, it is initialized from left to right. For mysql, it is initialized from
// right to left.
ARRAY_FOREACH(rollup_exprs, i) {
const ObRawExpr* raw_expr = rollup_exprs.at(i);
ObExpr *expr = NULL;
if (OB_FAIL(generate_rt_expr(*raw_expr, expr))) {
LOG_WARN("failed to generate_rt_expr", K(ret));
} else if (FALSE_IT(is_duplicate = (has_exist_in_array(spec.group_exprs_, expr)
|| has_exist_in_array(spec.rollup_exprs_, expr)))) {
} else if (FALSE_IT(is_duplicate = (is_oracle_mode && // set is_duplicate to false in mysql
(has_exist_in_array(spec.group_exprs_, expr)
|| has_exist_in_array(spec.rollup_exprs_, expr))))) {
} else if (OB_FAIL(spec.is_duplicate_rollup_expr_.push_back(is_duplicate))) {
OB_LOG(WARN, "fail to push distinct_rollup_expr", K(ret));
} else if (OB_FAIL(spec.add_rollup_expr(expr))) {
@ -3519,6 +3543,21 @@ int ObStaticEngineCG::generate_spec(ObLogGroupBy &op, ObMergeGroupBySpec &spec,
LOG_DEBUG("rollup is duplicate key", K(is_duplicate));
}
} // end for
// mysql mode, reinit duplicate rollup expr from right to left
if (OB_SUCC(ret) && !is_oracle_mode && rollup_exprs.count() > 0) {
for (int64_t i = spec.rollup_exprs_.count() - 2; OB_SUCC(ret) && i >= 0; --i) {
if (has_exist_in_array(spec.group_exprs_, spec.rollup_exprs_.at(i))) {
spec.is_duplicate_rollup_expr_.at(i) = true;
} else {
for (int64_t j = i + 1; !spec.is_duplicate_rollup_expr_.at(i)
&& j < spec.rollup_exprs_.count(); ++j) {
if (spec.rollup_exprs_.at(i) == spec.rollup_exprs_.at(j)) {
spec.is_duplicate_rollup_expr_.at(i) = true;
}
}
}
}
}
}
// 3. add aggr columns