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Add support for MySQL 8.0.1+ locking features (FOR SHARE, NOWAIT, SKIP LOCKED) #150

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Add support for MySQL 8.0.1+ locking features (FOR SHARE, NOWAIT, SKIP LOCKED) #150

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80b3583
Add support for MySQL 8.0.1+ locking features
StefanStuehrmann Apr 11, 2025
70afdd5
Add comprehensive test coverage for MySQL locking features
StefanStuehrmann Apr 11, 2025
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65 changes: 57 additions & 8 deletions lib/DBIx/Class/SQLMaker/MySQL.pm
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Original file line number Diff line number Diff line change
Expand Up @@ -97,19 +97,68 @@ sub delete {
return ($sql, @bind);
}

# LOCK IN SHARE MODE
my $for_syntax = {
update => 'FOR UPDATE',
shared => 'LOCK IN SHARE MODE'
#
# Support for MySQL lock clause syntax according to specification
# including updates introduced in MySQL 8.0.1)
# FOR UPDATE | FOR SHARE [OF tbl_name [, tbl_name] ...] [NOWAIT | SKIP LOCKED]
#

my $lock_types = {
update => 'FOR UPDATE',
share => 'FOR SHARE',
shared => 'LOCK IN SHARE MODE' # Deprecated but maintained
};

my $lock_modifiers = {
nowait => 'NOWAIT',
skip_locked => 'SKIP LOCKED'
};

sub _lock_select {
my ($self, $type) = @_;
my ($self, $type) = @_;

my $sql = $for_syntax->{$type}
|| $self->throw_exception("Unknown SELECT .. FOR type '$type' requested");
if ($type eq 'shared') {
warnings::warnif(
'deprecated',
"'for => 'shared'' is deprecated. Please use 'for => 'share'' instead"
);
}

# Handle hash-based configuration to support new featureset
if (ref $type eq 'HASH') {
my $lock_type = $type->{type};
my $tables = $type->{of};
my $modifier = $type->{modifier};

my $lock_clause = $lock_types->{$lock_type}
|| $self->throw_exception("Unknown SELECT .. FOR type '$lock_type' requested");

# Add OF clause if tables are specified
if ($tables) {
my @table_list = ref $tables eq 'ARRAY' ? @$tables : ($tables);
if (@table_list) {
my $quoted_tables = join(', ',
map { $self->_quote($_) } @table_list
);
$lock_clause .= " OF $quoted_tables";
}
}

# Add modifier if specified
if ($modifier) {
my $mod_sql = $lock_modifiers->{$modifier}
|| $self->throw_exception("Unknown lock modifier '$modifier' requested");
$lock_clause .= " $mod_sql";
}

return " $lock_clause";
}

return " $sql";
# Handle simple string types (for backward compatibility)
my $sql = $lock_types->{$type}
|| $self->throw_exception("Unknown SELECT .. FOR type '$type' requested");

return " $sql";
}

1;
165 changes: 165 additions & 0 deletions t/sqlmaker/mysql.t
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Original file line number Diff line number Diff line change
Expand Up @@ -152,4 +152,169 @@ for (
);
}

# Test support for locking clauses
{
# Test basic locking options
is_same_sql_bind(
$schema->resultset('Artist')->search({}, {for => 'update'})->as_query,
'(
SELECT `me`.`artistid`, `me`.`name`, `me`.`rank`, `me`.`charfield`
FROM `artist` `me`
FOR UPDATE
)',
[],
'FOR UPDATE lock works correctly'
);

is_same_sql_bind(
$schema->resultset('Artist')->search({}, {for => 'shared'})->as_query,
'(
SELECT `me`.`artistid`, `me`.`name`, `me`.`rank`, `me`.`charfield`
FROM `artist` `me`
LOCK IN SHARE MODE
)',
[],
'LOCK IN SHARE MODE (deprecated shared) works correctly'
);

is_same_sql_bind(
$schema->resultset('Artist')->search({}, {for => 'share'})->as_query,
'(
SELECT `me`.`artistid`, `me`.`name`, `me`.`rank`, `me`.`charfield`
FROM `artist` `me`
FOR SHARE
)',
[],
'FOR SHARE (new share syntax) works correctly'
);

# Test hash-based locking configuration
is_same_sql_bind(
$schema->resultset('Artist')->search({}, {for => {type => 'update'}})->as_query,
'(
SELECT `me`.`artistid`, `me`.`name`, `me`.`rank`, `me`.`charfield`
FROM `artist` `me`
FOR UPDATE
)',
[],
'Hash-based FOR UPDATE works correctly'
);

is_same_sql_bind(
$schema->resultset('Artist')->search({}, {for => {type => 'share'}})->as_query,
'(
SELECT `me`.`artistid`, `me`.`name`, `me`.`rank`, `me`.`charfield`
FROM `artist` `me`
FOR SHARE
)',
[],
'Hash-based FOR SHARE works correctly'
);

# Test NOWAIT modifier
is_same_sql_bind(
$schema->resultset('Artist')->search({}, {for => {type => 'update', modifier => 'nowait'}})->as_query,
'(
SELECT `me`.`artistid`, `me`.`name`, `me`.`rank`, `me`.`charfield`
FROM `artist` `me`
FOR UPDATE NOWAIT
)',
[],
'FOR UPDATE NOWAIT works correctly'
);

is_same_sql_bind(
$schema->resultset('Artist')->search({}, {for => {type => 'share', modifier => 'nowait'}})->as_query,
'(
SELECT `me`.`artistid`, `me`.`name`, `me`.`rank`, `me`.`charfield`
FROM `artist` `me`
FOR SHARE NOWAIT
)',
[],
'FOR SHARE NOWAIT works correctly'
);

# Test SKIP LOCKED modifier
is_same_sql_bind(
$schema->resultset('Artist')->search({}, {for => {type => 'update', modifier => 'skip_locked'}})->as_query,
'(
SELECT `me`.`artistid`, `me`.`name`, `me`.`rank`, `me`.`charfield`
FROM `artist` `me`
FOR UPDATE SKIP LOCKED
)',
[],
'FOR UPDATE SKIP LOCKED works correctly'
);

is_same_sql_bind(
$schema->resultset('Artist')->search({}, {for => {type => 'share', modifier => 'skip_locked'}})->as_query,
'(
SELECT `me`.`artistid`, `me`.`name`, `me`.`rank`, `me`.`charfield`
FROM `artist` `me`
FOR SHARE SKIP LOCKED
)',
[],
'FOR SHARE SKIP LOCKED works correctly'
);

# Test OF clause
is_same_sql_bind(
$schema->resultset('Artist')->search({}, {for => {type => 'update', of => 'artist'}})->as_query,
'(
SELECT `me`.`artistid`, `me`.`name`, `me`.`rank`, `me`.`charfield`
FROM `artist` `me`
FOR UPDATE OF `artist`
)',
[],
'FOR UPDATE OF table works correctly'
);

# Test OF clause with multiple tables
is_same_sql_bind(
$schema->resultset('Artist')->search({}, {for => {type => 'share', of => ['artist', 'cd']}})->as_query,
'(
SELECT `me`.`artistid`, `me`.`name`, `me`.`rank`, `me`.`charfield`
FROM `artist` `me`
FOR SHARE OF `artist`, `cd`
)',
[],
'FOR SHARE OF multiple tables works correctly'
);

# Test combination of OF clause and modifier
is_same_sql_bind(
$schema->resultset('Artist')->search({}, {
for => {
type => 'update',
of => 'artist',
modifier => 'nowait'
}
})->as_query,
'(
SELECT `me`.`artistid`, `me`.`name`, `me`.`rank`, `me`.`charfield`
FROM `artist` `me`
FOR UPDATE OF `artist` NOWAIT
)',
[],
'FOR UPDATE OF table NOWAIT works correctly'
);

is_same_sql_bind(
$schema->resultset('Artist')->search({}, {
for => {
type => 'share',
of => ['artist', 'cd'],
modifier => 'skip_locked'
}
})->as_query,
'(
SELECT `me`.`artistid`, `me`.`name`, `me`.`rank`, `me`.`charfield`
FROM `artist` `me`
FOR SHARE OF `artist`, `cd` SKIP LOCKED
)',
[],
'FOR SHARE OF multiple tables SKIP LOCKED works correctly'
);
}

done_testing;