Work round MySQL/InnoDB bug http://bugs.mysql.com/bug.php?id=13741

diff --git a/lib/SQL/Translator/Producer/MySQL.pm b/lib/SQL/Translator/Producer/MySQL.pm
index a1f0c37..3f7122d 100644 (file)
--- a/lib/SQL/Translator/Producer/MySQL.pm
+++ b/lib/SQL/Translator/Producer/MySQL.pm
@@ -660,10 +660,40 @@ sub drop_field
 sub batch_alter_table {
   my ($table, $diff_hash, $options) = @_;
 
+  # InnoDB has an issue with dropping and re-adding a FK constraint under the 
+  # name in a single alter statment, see: http://bugs.mysql.com/bug.php?id=13741
+  #
+  # We have to work round this.
+
+  my %fks_to_alter;
+  my %fks_to_drop = map {
+    $_->type eq FOREIGN_KEY 
+              ? ( $_->name => $_ ) 
+              : ( )
+  } @{$diff_hash->{alter_drop_constraint} };
+
+  my %fks_to_create = map {
+    if ( $_->type eq FOREIGN_KEY) {
+      $fks_to_alter{$_->name} = $fks_to_drop{$_->name} if $fks_to_drop{$_->name};
+      ( $_->name => $_ );
+    } else { ( ) }
+  } @{$diff_hash->{alter_create_constraint} };
+
+  my $drop_stmt = '';
+  if (scalar keys %fks_to_alter) {
+    $diff_hash->{alter_drop_constraint} = [
+      grep { !$fks_to_alter{$_->name} } @{ $diff_hash->{alter_drop_constraint} }
+    ];
+
+    $drop_stmt = batch_alter_table($table, { alter_drop_constraint => [ values %fks_to_alter ] }, $options) 
+               . "\n";
+
+  }
+
   my @stmts = map {
     if (@{ $diff_hash->{$_} || [] }) {
       my $meth = __PACKAGE__->can($_) or die __PACKAGE__ . " cant $_";
-      map { $meth->(ref $_ eq 'ARRAY' ? @$_ : $_) } @{ $diff_hash->{$_} }
+      map { $meth->( (ref $_ eq 'ARRAY' ? @$_ : $_), $options ) } @{ $diff_hash->{$_} }
     } else { () }
   } qw/rename_table
        alter_drop_constraint
@@ -683,7 +713,7 @@ sub batch_alter_table {
 
   return unless @stmts;
   # Just zero or one stmts. return now
-  return "@stmts;" unless @stmts > 1;
+  return "$drop_stmt@stmts;" unless @stmts > 1;
 
   # Now strip off the 'ALTER TABLE xyz' of all but the first one
 
@@ -697,7 +727,7 @@ sub batch_alter_table {
   $re = qr/^ALTER TABLE \Q$qt@{[$table->name]}$qt\E / if $renamed_from;
   my $padd = " " x length($alter_table);
 
-  return join( ",\n", $first, map { s/$re//; $padd . $_ } @stmts) . ';';
+  return $drop_stmt . join( ",\n", $first, map { s/$re//; $padd . $_ } @stmts) . ';';
 }
 
 sub drop_table {

diff --git a/t/30sqlt-new-diff-mysql.t b/t/30sqlt-new-diff-mysql.t
index a4cca87..867931a 100644 (file)
--- a/t/30sqlt-new-diff-mysql.t
+++ b/t/30sqlt-new-diff-mysql.t
@@ -10,8 +10,10 @@ use FindBin qw($Bin);
 use Test::More;
 use Test::Differences;
 use Test::SQL::Translator qw(maybe_plan);
+use SQL::Translator::Schema::Constants;
+use Storable 'dclone';
 
-plan tests => 5;
+plan tests => 6;
 
 use_ok('SQL::Translator::Diff') or die "Cannot continue\n";
 
@@ -36,7 +38,7 @@ my $out = SQL::Translator::Diff::schema_diff( $source_schema, 'MySQL', $target_s
 eq_or_diff($out, <<'## END OF DIFF', "Diff as expected");
 -- Convert schema 'create1.yml' to 'create2.yml':
 
-BEGIN TRANSACTION;
+BEGIN;
 
 SET foreign_key_checks=0;
 
@@ -80,7 +82,7 @@ $out = SQL::Translator::Diff::schema_diff($source_schema, 'MySQL', $target_schem
 eq_or_diff($out, <<'## END OF DIFF', "Diff as expected");
 -- Convert schema 'create1.yml' to 'create2.yml':
 
-BEGIN TRANSACTION;
+BEGIN;
 
 SET foreign_key_checks=0;
 
@@ -147,7 +149,7 @@ eq_or_diff($out, <<'## END OF DIFF', "No differences found");
   eq_or_diff($out, <<'## END OF DIFF', "No differences found");
 -- Convert schema 'create.sql' to 'create2.yml':
 
-BEGIN TRANSACTION;
+BEGIN;
 
 SET foreign_key_checks=0;
 
@@ -180,3 +182,50 @@ DROP TABLE deleted;
 COMMIT;
 ## END OF DIFF
 }
+
+# Test InnoDB stupidness. Have to drop constraints before re-adding them if
+# they are just alters.
+
+
+{
+  my $s1 = SQL::Translator::Schema->new;
+  my $s2 = SQL::Translator::Schema->new;
+
+  $s1->name('Schema 1');
+  $s2->name('Schema 2');
+
+  my $t1 = $s1->add_table($target_schema->get_table('employee'));
+  my $t2 = $s2->add_table(dclone($target_schema->get_table('employee')));
+
+
+  my ($c) = grep { $_->name eq 'FK5302D47D93FE702E_diff' } $t2->get_constraints;
+  $c->on_delete('CASCADE');
+
+  $t2->add_constraint(
+    name => 'new_constraint',
+    type => 'FOREIGN KEY',
+    fields => ['employee_id'],
+    reference_fields => ['fake'],
+    reference_table => 'patty',
+  );
+
+  $t2->add_field(
+    name => 'new',
+    data_type => 'int'
+  );
+
+  $out = SQL::Translator::Diff::schema_diff($s1, 'MySQL', $s2, 'MySQL' );
+
+  eq_or_diff($out, <<'## END OF DIFF', "Batch alter of constraints work for InnoDB");
+-- Convert schema 'Schema 1' to 'Schema 2':
+
+BEGIN;
+
+ALTER TABLE employee DROP FOREIGN KEY FK5302D47D93FE702E_diff;
+ALTER TABLE employee ADD COLUMN new integer,
+                     ADD CONSTRAINT FK5302D47D93FE702E_diff FOREIGN KEY (employee_id) REFERENCES person (person_id) ON DELETE CASCADE,
+                     ADD CONSTRAINT new_constraint FOREIGN KEY (employee_id) REFERENCES patty (fake);
+
+COMMIT;
+## END OF DIFF
+}