When prepared on a DB, prepared statement code in database/sql handles everything to keep the prepared statement alive as it moves across the connection pool. Understanding this is an important part of using this API correctly, but it was only documented indirectly via `(*Tx) Prepare*`.
Change-Id: Ic8757e0150d59e675d9f0252f6c15aef2cc2e831
GitHub-Last-Rev: 55dba87458
GitHub-Pull-Request: golang/go#29890
Reviewed-on: https://go-review.googlesource.com/c/159077
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Daniel Theophanes <kardianos@gmail.com>
The logic for pulling a database connection from the DB pool should
proceed as follows: attempt to pull either a cached connection or
new connection N times in a loop. If each connection results
in a bad connection, then create a new connection (no cache).
Previously pulling a Conn from the pool, the last step also
looked at the cache, rather then always creating a new connection.
Fixes#29684
Change-Id: I8f436fd9b96eb35502a620ebe8da4ab89fb06a2e
Reviewed-on: https://go-review.googlesource.com/c/157637
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Show two larger application examples. One example that
could be used in a CLI, the other in a long running
service. These demonstarates different strategies for
handling DB.Ping errors in context.
Fixes#23738
Change-Id: Id01213caf1f47917239a7506b01d30e37db74d31
Reviewed-on: https://go-review.googlesource.com/c/101216
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This CL add support for converting a returned cursor (presented
to this package as a driver.Rows) and scanning it into a *Rows.
Fixes#28515
Change-Id: Id8191c568dc135af9e5e8555efcd01987708edcb
Reviewed-on: https://go-review.googlesource.com/c/145738
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Go documentation style for boolean funcs is to say:
// Foo reports whether ...
func Foo() bool
(rather than "returns true if")
This CL also replaces 4 uses of "iff" with the same "reports whether"
wording, which doesn't lose any meaning, and will prevent people from
sending typo fixes when they don't realize it's "if and only if". In
the past I think we've had the typo CLs updated to just say "reports
whether". So do them all at once.
(Inspired by the addition of another "returns true if" in CL 146938
in fd_plan9.go)
Created with:
$ perl -i -npe 's/returns true if/reports whether/' $(git grep -l "returns true iff" | grep -v vendor)
$ perl -i -npe 's/returns true if/reports whether/' $(git grep -l "returns true if" | grep -v vendor)
Change-Id: Ided502237f5ab0d25cb625dbab12529c361a8b9f
Reviewed-on: https://go-review.googlesource.com/c/147037
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The old one was rather confusing - it makes it sound like the user has done something wrong.
Change-Id: Ibc7411f4f1d5f6c66fbcaac64bb05b0743354418
GitHub-Last-Rev: 09290accdd
GitHub-Pull-Request: golang/go#27979
Reviewed-on: https://go-review.googlesource.com/c/139102
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Daniel Theophanes <kardianos@gmail.com>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Previously the MaxIdleClosed counter was incremented when added
to the free connection list, rather then when it wasn't added
to the free connection list. Flip this logic to correct.
Fixes#27792
Change-Id: I405302c14fb985369dab48fbe845e5651afc4ccf
Reviewed-on: https://go-review.googlesource.com/c/138578
Run-TryBot: Daniel Theophanes <kardianos@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
It was unclear that users must copy values out of the src value
for value types like []byte.
Fixes#24492
Change-Id: I99ad61e0ad0075b9efc5ee4e0d067f752f91b8fa
Reviewed-on: https://go-review.googlesource.com/108535
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Provide better statistics for the database pool. Add counters
for waiting on the pool and closes. Too much waiting or too many
connection closes could indicate a problem.
Fixes#24683Fixes#22138
Change-Id: I9e1e32a0487edf41c566b8d9c07cb55e04078fec
Reviewed-on: https://go-review.googlesource.com/108536
Run-TryBot: Daniel Theophanes <kardianos@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
The connRequest may return a nil conn value. However in a rare
case that is difficult to test for it was being passed to
DB.putConn without a nil check. This was an error as this
made no sense if the driverConn is nil. This also caused
a panic in putConn.
A test for this would be nice, but didn't find a sane
way to test for this condition.
Fixes#24445
Change-Id: I827316e856788a5a3ced913f129bb5869b7bcf68
Reviewed-on: https://go-review.googlesource.com/102477
Run-TryBot: Daniel Theophanes <kardianos@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alexey Palazhchenko <alexey.palazhchenko@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Ensure all error prefixes in the "database/sql" package start with
"sql: ". Do not prefix errors for type conversions because they
are always embedded in another error message with a specific
context.
Fixes#25251
Change-Id: I349d9804f3bfda4eeb755b32b508ec5992c28e07
Reviewed-on: https://go-review.googlesource.com/111637
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Fixes golint warning about "if block ends with a return statement,
so drop this else and outdent its block".
Change-Id: Iac4fd324e04e3e3fe3e3933f5e59095041d292c5
Reviewed-on: https://go-review.googlesource.com/107115
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Daniel Theophanes <kardianos@gmail.com>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This commit includes efficiency improvements in two places in the
database/sql package where an "if err != nil" was redundant and
the error can be returned as-is (most of the code in the standard
library and even in the file I changed does it my suggested way).
Change-Id: Ib9dac69ed01ee846e570a776164cb87c2caee6ca
Reviewed-on: https://go-review.googlesource.com/106555
Reviewed-by: Daniel Theophanes <kardianos@gmail.com>
Run-TryBot: Daniel Theophanes <kardianos@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The previous implementation would return "sql: Rows are closed" for any
context errors, which can be confusing for context timeouts or
cancelations.
Fixes#24431
Change-Id: I884904ec43204c43f4e94e2335b2802aab77a888
Reviewed-on: https://go-review.googlesource.com/104276
Reviewed-by: Daniel Theophanes <kardianos@gmail.com>
Run-TryBot: Daniel Theophanes <kardianos@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
It wasn't clear for existing docs if DB.Close forcefully closed
connections or waited for them to finish.
Fixes#23753
Change-Id: Id7df31224c93181c8d01bab7b0b23da25b42a288
Reviewed-on: https://go-review.googlesource.com/103397
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Prevent queries from starting a goroutine if the context is
not able to be canceled.
Fixes#23879
Change-Id: I392047bd53d7f796219dd12ee11b07303658fdaf
Reviewed-on: https://go-review.googlesource.com/102478
Run-TryBot: Daniel Theophanes <kardianos@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Yasuhiro MATSUMOTO <mattn.jp@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This aims to expand the coverage of examples showing how the sql
package works, as well as to address a number of issues I've observed
while explaining how the database package works:
- The best way to issue UPDATE or INSERT queries, that don't need
to scan anything in return. (Previously, we had no examples for any
Execute statement).
- How to use prepared statements and transactions.
- How to aggregate arguments from a Query/QueryContext query into
a slice.
Furthermore just having examples in more places should help, as users
click on e.g. the "Rows" return parameter and are treated with the
lack of any example about how Rows is used.
Switch package examples to use QueryContext/QueryRowContext; I think
it is a good practice to prepare users to issue queries with a timeout
attached, even if they are not using it immediately.
Change-Id: I4e63af91c7e4fff88b25f820906104ecefde4cc3
Reviewed-on: https://go-review.googlesource.com/91015
Reviewed-by: Daniel Theophanes <kardianos@gmail.com>
Run-TryBot: Daniel Theophanes <kardianos@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Since https://golang.org/cl/38533, this validation is performed in
driverArgs.
Change-Id: I13a3ca46a1aa3197370de1095fb46ab83ea4628c
Reviewed-on: https://go-review.googlesource.com/91115
Reviewed-by: Daniel Theophanes <kardianos@gmail.com>
Run-TryBot: Daniel Theophanes <kardianos@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
When 'convertAssign' gives an error, instead of giving just the index of
the failing column -- which is not always helpful, especially when there
are lots of columns in the query -- utilize 'rs.rowsi.Columns()' to
extract the underlying column name and include that in the error string:
sql: Scan error on column index 0, name "some_column": ...
Fixes#23362
Change-Id: I0fe71ff3c25f4c0dd9fc6aa2c2da2360dd93e3e0
Reviewed-on: https://go-review.googlesource.com/86537
Reviewed-by: Harald Nordgren <haraldnordgren@gmail.com>
Reviewed-by: Daniel Theophanes <kardianos@gmail.com>
Run-TryBot: Daniel Theophanes <kardianos@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Previously we allowed drivers to modify the row buffer used to scan
values when closing Rows. This is no longer acceptable and can lead
to data races.
Fixes#23519
Change-Id: I91820a6266ffe52f95f40bb47307d375727715af
Reviewed-on: https://go-review.googlesource.com/89936
Run-TryBot: Daniel Theophanes <kardianos@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Provide a fresh conversion table for TestConversions as it gets
modified on each test.
Change-Id: I6e2240d0c3455451271a6879e994b82222c3d44c
Reviewed-on: https://go-review.googlesource.com/89595
Run-TryBot: Daniel Theophanes <kardianos@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
During the refactor in 1126d1483f I
introduced a logical error within one withLock function that used
the result of the call before checking for the error. Change
the order so that the error is checked before the result is used.
None of the other withLock uses have similar issues.
Fixes#23208
Change-Id: I6c5dcf262e36bad4369c850f1e0131066360a82e
Reviewed-on: https://go-review.googlesource.com/85175
Run-TryBot: Daniel Theophanes <kardianos@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Caleb Spare <cespare@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The driver.Value type may be more then the documented 6 types if the
database driver supports it. Document that fact.
Updates #23077
Change-Id: If7e2112fa61a8cc4e155bb31e94e89b20c607242
Reviewed-on: https://go-review.googlesource.com/84636
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
The docs make it seem like they are all things a single object
would implement. That's true of Driver and DriverContext,
but Connector is really something else. Attempt to clarify.
Change-Id: I8fdf1cff855a0fbe37ea22720c082045c719a267
Reviewed-on: https://go-review.googlesource.com/82082
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Daniel Theophanes <kardianos@gmail.com>
When the user context which passed in (*DB)BeginTx is canceled or
timeout, the current implementation could cause db transaction leak
in some extreme scenario.
Goroutine 1:
Call (*DB) BeginTx begins a transaction with a userContext.
In (*DB)BeginTx, a new goroutine (*Tx)awaitDone
which monitor context and rollback tx if needed will be created
Goroutine 2(awaitDone):
block on tx.ctx.Done()
Goroutine 1:
Execute some insert or update sqls on the database
Goroutine 1:
Commit the transaction, (*Tx)Commit set
the atomic variable tx.done to 1
Goroutine 3(maybe global timer):
Cancel userContext which be passed in Tx
Goroutine 1:
(*Tx)Commit checks tx.ctx.Done().
Due to the context has been canceled, it will return
context.Canceled or context.DeadlineExceeded error immediately
and abort the real COMMIT operation of transaction
Goroutine 2:
Release with tx.ctx.Done() signal, execute (*Tx)rollback.
However the atomic variable tx.done is 1 currently,
it will return ErrTxDone error immediately and
abort the real ROLLBACK operation of transaction
Fixes#22976
Change-Id: I3bc23adf25db823861d91e33d3cca6189fb1171d
Reviewed-on: https://go-review.googlesource.com/81736
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Daniel Theophanes <kardianos@gmail.com>
Check for the expected number of arguments in a SQL statement
after arguments are eliminated in the argument converter.
This situation was already tested for in TestNamedValueChecker.
However the test used Exec which didn't have any check for
NumInput on it at all, thus this issue was never caught.
In addition to moving the NumInput check on the Query
methods after the converter, add the NumInput check
to the Exec methods as well.
Fixes#22630
Change-Id: If45920c6e1cf70dca63822a0cedec2cdc5cc611c
Reviewed-on: https://go-review.googlesource.com/76732
Run-TryBot: Daniel Theophanes <kardianos@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
While driver.Connector was previously added to allow non-string
connection arguments and access to the context, most users of
the sql package will continue to rely on a string DSN.
Allow drivers to implement a string DSN to Connector interface
that both allows a single parsing of the string DSN and uses
the Connector interface which passes available context to
the driver dialer.
Fixes#22713
Change-Id: Ia0b862262f4c4670effe2538d0d6d43733fea18d
Reviewed-on: https://go-review.googlesource.com/77550
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
CL 21663 allowed drivers to implement ExecerContext without
also implementing Execer, and similarly QueryerContext without
Queryer, but it did not make that clear in the documentation.
This CL updates the documentation.
Change-Id: I9a4accaac32edfe255fe7c0b0907d4c1014322b4
Reviewed-on: https://go-review.googlesource.com/78129
Reviewed-by: Daniel Theophanes <kardianos@gmail.com>
ctx.Done() == ctx.Background().Done() is just
a long way to write ctx.Done() == nil.
Use the short way.
Change-Id: I7b3198b5dc46b8b40086243aa61882bc8c268eac
Reviewed-on: https://go-review.googlesource.com/78128
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Originally we tried the strict -er suffix as the rule in this case
but eventually we decided it was too awkward: io.WriteByter
became io.ByteWriter. By analogy, here the interface should be
named SessionResetter instead of the awkward ResetSessioner.
This change should not affect any drivers that have already
implemented the interface, because the method name is not changing.
(This was added during the Go 1.10 cycle and has not been
released yet, so we can change it.)
Change-Id: Ie50e4e090d3811f85965da9da37d966e9f45e79d
Reviewed-on: https://go-review.googlesource.com/78127
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Daniel Theophanes <kardianos@gmail.com>
Before terminating the connectionResetter goroutine the connection
pool processes all of the connections on the channel to unlock the
driverConn instances so everthing can shutdown cleanly. However
the channel was never closed so the goroutine hangs on the range.
Close the channel prior to ranging over it. Also prevent additional
connections from being sent to the resetter after the connection
pool has been closed.
Fixes#22699
Change-Id: I440d2b13cbedec2e04621557f5bd0b1526933dd7
Reviewed-on: https://go-review.googlesource.com/77390
Run-TryBot: Daniel Theophanes <kardianos@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
The go repository contains a mix of github.com/golang/go/issues/xxxxx
and golang.org/issues/xxxxx URLs for references to issues in the issue
tracker. We should use one for consistency, and golang.org is preferred
in case the project moves the issue tracker in the future.
This reasoning is taken from a comment Sam Whited left on a CL I
recently opened: https://go-review.googlesource.com/c/go/+/73890.
In that CL I referenced an issue using its github.com URL, because other
tests in the file I was changing contained references to issues using
their github.com URL. Sam Whited left a comment on the CL stating I
should change it to the golang.org URL.
If new code is intended to reference issues via golang.org and not
github.com, existing code should be updated so that precedence exists
for contributors who are looking at the existing code as a guide for the
code they should write.
Change-Id: I3b9053fe38a1c56fc101a8b7fd7b8f310ba29724
Reviewed-on: https://go-review.googlesource.com/75673
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Previously scanning time.Time into a *time.Time required reflection.
Now it does not. Scanning already checked if the source value was of
type time.Time. The only addition was checking the destination was
of type *time.Time.
Existing tests already scan time.Time into *time.Time, so no new
tests were added. Linked issue has performance justification.
Fixes#22300
Change-Id: I4eea461c78fad71ce76e7677c8503a1919666931
Reviewed-on: https://go-review.googlesource.com/73232
Run-TryBot: Daniel Theophanes <kardianos@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Andrei Matei
Zhou Peng
Justin Li
Daniel Theophanes
Tobias Klauser
Brad Fitzpatrick
Vladimir Kovpak
Umang Parmar
Igor Zhilianin
Tim
Alexey Palazhchenko
Frédéric Guillot
Eugene Kalinin
weeellz
dchenk
Eric Rykwalder
Andrew Bonventre
Kevin Burke
Shawn Smith
Ryuma Yoshida
Tamir Duberstein
HaraldNordgren
Russ Cox
kirk
Leigh McCulloch