Skip to content

Fix mysql return bug#4450

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
morningman merged 3 commits into from
Aug 27, 2020
Merged

Fix mysql return bug #4450

Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
cde69da
fix mysql return bug
Aug 25, 2020
e1a7d96
fix bug
Aug 25, 2020
9c326d5
add comment
Aug 26, 2020
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
16 changes: 10 additions & 6 deletions fe/fe-core/src/main/java/org/apache/doris/qe/StmtExecutor.java
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -608,9 +608,6 @@ private void handleQueryStmt() throws Exception {

coord.exec();

// if python's MysqlDb get error after sendfields, it can't catch the exception
// so We need to send fields after first batch arrived

// send result
// 1. If this is a query with OUTFILE clause, eg: select * from tbl1 into outfile xxx,
// We will not send real query result to client. Instead, we only send OK to client with
Expand All@@ -622,13 +619,17 @@ private void handleQueryStmt() throws Exception {
RowBatch batch;
MysqlChannel channel = context.getMysqlChannel();
boolean isOutfileQuery = queryStmt.hasOutFileClause();
if (!isOutfileQuery) {
sendFields(queryStmt.getColLabels(), queryStmt.getResultExprs());
}
boolean isSendFields = false;

@morningmanmorningmanAug 25, 2020

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

So the reason is that the fields has been sent but no data is sent following?

@gengjun-gitgengjun-gitAug 26, 2020

Copy link
Copy Markdown
ContributorAuthor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Yes, fields has been sent, but query may fail because of timeout. In this case, client will get a fields packet, and error packet, but some language mysql driver cannot recognize the error, and returns a success and no rows result.

while (true) {
batch = coord.getNext();
// for outfile query, there will be only one empty batch send back with eos flag
if (batch.getBatch() != null && !isOutfileQuery) {
// For some language driver, getting error packet after fields packet will be recognized as a success result
// so We need to send fields after first batch arrived
if (!isSendFields) {
sendFields(queryStmt.getColLabels(), queryStmt.getResultExprs());
isSendFields = true;
}
for (ByteBuffer row : batch.getBatch().getRows()) {
channel.sendOnePacket(row);
}
Expand All@@ -638,6 +639,9 @@ private void handleQueryStmt() throws Exception {
break;
}
}
if (!isSendFields && !isOutfileQuery) {
sendFields(queryStmt.getColLabels(), queryStmt.getResultExprs());
}

statisticsForAuditLog = batch.getQueryStatistics();
if (!isOutfileQuery) {
Expand Down