<?php
namespace Doctrine\DBAL\Schema;
use Doctrine\DBAL\Types;
use function array_intersect_key;
use function array_key_exists;
use function array_keys;
use function array_map;
use function array_merge;
use function array_unique;
use function assert;
use function count;
use function get_class;
use function strtolower;
/**
* Compares two Schemas and return an instance of SchemaDiff.
*/
class Comparator
{
/**
* @return SchemaDiff
*
* @throws SchemaException
*/
public static function compareSchemas(Schema $fromSchema, Schema $toSchema)
{
$c = new self();
return $c->compare($fromSchema, $toSchema);
}
/**
* Returns a SchemaDiff object containing the differences between the schemas $fromSchema and $toSchema.
*
* The returned differences are returned in such a way that they contain the
* operations to change the schema stored in $fromSchema to the schema that is
* stored in $toSchema.
*
* @return SchemaDiff
*
* @throws SchemaException
*/
public function compare(Schema $fromSchema, Schema $toSchema)
{
$diff = new SchemaDiff();
$diff->fromSchema = $fromSchema;
$foreignKeysToTable = [];
foreach ($toSchema->getNamespaces() as $namespace) {
if ($fromSchema->hasNamespace($namespace)) {
continue;
}
$diff->newNamespaces[$namespace] = $namespace;
}
foreach ($fromSchema->getNamespaces() as $namespace) {
if ($toSchema->hasNamespace($namespace)) {
continue;
}
$diff->removedNamespaces[$namespace] = $namespace;
}
foreach ($toSchema->getTables() as $table) {
$tableName = $table->getShortestName($toSchema->getName());
if (! $fromSchema->hasTable($tableName)) {
$diff->newTables[$tableName] = $toSchema->getTable($tableName);
} else {
$tableDifferences = $this->diffTable(
$fromSchema->getTable($tableName),
$toSchema->getTable($tableName)
);
if ($tableDifferences !== false) {
$diff->changedTables[$tableName] = $tableDifferences;
}
}
}
/* Check if there are tables removed */
foreach ($fromSchema->getTables() as $table) {
$tableName = $table->getShortestName($fromSchema->getName());
$table = $fromSchema->getTable($tableName);
if (! $toSchema->hasTable($tableName)) {
$diff->removedTables[$tableName] = $table;
}
// also remember all foreign keys that point to a specific table
foreach ($table->getForeignKeys() as $foreignKey) {
$foreignTable = strtolower($foreignKey->getForeignTableName());
if (! isset($foreignKeysToTable[$foreignTable])) {
$foreignKeysToTable[$foreignTable] = [];
}
$foreignKeysToTable[$foreignTable][] = $foreignKey;
}
}
foreach ($diff->removedTables as $tableName => $table) {
if (! isset($foreignKeysToTable[$tableName])) {
continue;
}
$diff->orphanedForeignKeys = array_merge($diff->orphanedForeignKeys, $foreignKeysToTable[$tableName]);
// deleting duplicated foreign keys present on both on the orphanedForeignKey
// and the removedForeignKeys from changedTables
foreach ($foreignKeysToTable[$tableName] as $foreignKey) {
// strtolower the table name to make if compatible with getShortestName
$localTableName = strtolower($foreignKey->getLocalTableName());
if (! isset($diff->changedTables[$localTableName])) {
continue;
}
foreach ($diff->changedTables[$localTableName]->removedForeignKeys as $key => $removedForeignKey) {
assert($removedForeignKey instanceof ForeignKeyConstraint);
// We check if the key is from the removed table if not we skip.
if ($tableName !== strtolower($removedForeignKey->getForeignTableName())) {
continue;
}
unset($diff->changedTables[$localTableName]->removedForeignKeys[$key]);
}
}
}
foreach ($toSchema->getSequences() as $sequence) {
$sequenceName = $sequence->getShortestName($toSchema->getName());
if (! $fromSchema->hasSequence($sequenceName)) {
if (! $this->isAutoIncrementSequenceInSchema($fromSchema, $sequence)) {
$diff->newSequences[] = $sequence;
}
} else {
if ($this->diffSequence($sequence, $fromSchema->getSequence($sequenceName))) {
$diff->changedSequences[] = $toSchema->getSequence($sequenceName);
}
}
}
foreach ($fromSchema->getSequences() as $sequence) {
if ($this->isAutoIncrementSequenceInSchema($toSchema, $sequence)) {
continue;
}
$sequenceName = $sequence->getShortestName($fromSchema->getName());
if ($toSchema->hasSequence($sequenceName)) {
continue;
}
$diff->removedSequences[] = $sequence;
}
return $diff;
}
/**
* @param Schema $schema
* @param Sequence $sequence
*
* @return bool
*/
private function isAutoIncrementSequenceInSchema($schema, $sequence)
{
foreach ($schema->getTables() as $table) {
if ($sequence->isAutoIncrementsFor($table)) {
return true;
}
}
return false;
}
/**
* @return bool
*/
public function diffSequence(Sequence $sequence1, Sequence $sequence2)
{
if ($sequence1->getAllocationSize() !== $sequence2->getAllocationSize()) {
return true;
}
return $sequence1->getInitialValue() !== $sequence2->getInitialValue();
}
/**
* Returns the difference between the tables $fromTable and $toTable.
*
* If there are no differences this method returns the boolean false.
*
* @return TableDiff|false
*
* @throws SchemaException
*/
public function diffTable(Table $fromTable, Table $toTable)
{
$changes = 0;
$tableDifferences = new TableDiff($fromTable->getName());
$tableDifferences->fromTable = $fromTable;
$fromTableColumns = $fromTable->getColumns();
$toTableColumns = $toTable->getColumns();
/* See if all the columns in "from" table exist in "to" table */
foreach ($toTableColumns as $columnName => $column) {
if ($fromTable->hasColumn($columnName)) {
continue;
}
$tableDifferences->addedColumns[$columnName] = $column;
$changes++;
}
/* See if there are any removed columns in "to" table */
foreach ($fromTableColumns as $columnName => $column) {
// See if column is removed in "to" table.
if (! $toTable->hasColumn($columnName)) {
$tableDifferences->removedColumns[$columnName] = $column;
$changes++;
continue;
}
// See if column has changed properties in "to" table.
$changedProperties = $this->diffColumn($column, $toTable->getColumn($columnName));
if (count($changedProperties) === 0) {
continue;
}
$columnDiff = new ColumnDiff($column->getName(), $toTable->getColumn($columnName), $changedProperties);
$columnDiff->fromColumn = $column;
$tableDifferences->changedColumns[$column->getName()] = $columnDiff;
$changes++;
}
$this->detectColumnRenamings($tableDifferences);
$fromTableIndexes = $fromTable->getIndexes();
$toTableIndexes = $toTable->getIndexes();
/* See if all the indexes in "from" table exist in "to" table */
foreach ($toTableIndexes as $indexName => $index) {
if (($index->isPrimary() && $fromTable->hasPrimaryKey()) || $fromTable->hasIndex($indexName)) {
continue;
}
$tableDifferences->addedIndexes[$indexName] = $index;
$changes++;
}
/* See if there are any removed indexes in "to" table */
foreach ($fromTableIndexes as $indexName => $index) {
// See if index is removed in "to" table.
if (
($index->isPrimary() && ! $toTable->hasPrimaryKey()) ||
! $index->isPrimary() && ! $toTable->hasIndex($indexName)
) {
$tableDifferences->removedIndexes[$indexName] = $index;
$changes++;
continue;
}
// See if index has changed in "to" table.
$toTableIndex = $index->isPrimary() ? $toTable->getPrimaryKey() : $toTable->getIndex($indexName);
assert($toTableIndex instanceof Index);
if (! $this->diffIndex($index, $toTableIndex)) {
continue;
}
$tableDifferences->changedIndexes[$indexName] = $toTableIndex;
$changes++;
}
$this->detectIndexRenamings($tableDifferences);
$fromForeignKeys = $fromTable->getForeignKeys();
$toForeignKeys = $toTable->getForeignKeys();
foreach ($fromForeignKeys as $fromKey => $fromConstraint) {
foreach ($toForeignKeys as $toKey => $toConstraint) {
if ($this->diffForeignKey($fromConstraint, $toConstraint) === false) {
unset($fromForeignKeys[$fromKey], $toForeignKeys[$toKey]);
} else {
if (strtolower($fromConstraint->getName()) === strtolower($toConstraint->getName())) {
$tableDifferences->changedForeignKeys[] = $toConstraint;
$changes++;
unset($fromForeignKeys[$fromKey], $toForeignKeys[$toKey]);
}
}
}
}
foreach ($fromForeignKeys as $fromConstraint) {
$tableDifferences->removedForeignKeys[] = $fromConstraint;
$changes++;
}
foreach ($toForeignKeys as $toConstraint) {
$tableDifferences->addedForeignKeys[] = $toConstraint;
$changes++;
}
return $changes > 0 ? $tableDifferences : false;
}
/**
* Try to find columns that only changed their name, rename operations maybe cheaper than add/drop
* however ambiguities between different possibilities should not lead to renaming at all.
*
* @return void
*/
private function detectColumnRenamings(TableDiff $tableDifferences)
{
$renameCandidates = [];
foreach ($tableDifferences->addedColumns as $addedColumnName => $addedColumn) {
foreach ($tableDifferences->removedColumns as $removedColumn) {
if (count($this->diffColumn($addedColumn, $removedColumn)) !== 0) {
continue;
}
$renameCandidates[$addedColumn->getName()][] = [$removedColumn, $addedColumn, $addedColumnName];
}
}
foreach ($renameCandidates as $candidateColumns) {
if (count($candidateColumns) !== 1) {
continue;
}
[$removedColumn, $addedColumn] = $candidateColumns[0];
$removedColumnName = strtolower($removedColumn->getName());
$addedColumnName = strtolower($addedColumn->getName());
if (isset($tableDifferences->renamedColumns[$removedColumnName])) {
continue;
}
$tableDifferences->renamedColumns[$removedColumnName] = $addedColumn;
unset(
$tableDifferences->addedColumns[$addedColumnName],
$tableDifferences->removedColumns[$removedColumnName]
);
}
}
/**
* Try to find indexes that only changed their name, rename operations maybe cheaper than add/drop
* however ambiguities between different possibilities should not lead to renaming at all.
*
* @return void
*/
private function detectIndexRenamings(TableDiff $tableDifferences)
{
$renameCandidates = [];
// Gather possible rename candidates by comparing each added and removed index based on semantics.
foreach ($tableDifferences->addedIndexes as $addedIndexName => $addedIndex) {
foreach ($tableDifferences->removedIndexes as $removedIndex) {
if ($this->diffIndex($addedIndex, $removedIndex)) {
continue;
}
$renameCandidates[$addedIndex->getName()][] = [$removedIndex, $addedIndex, $addedIndexName];
}
}
foreach ($renameCandidates as $candidateIndexes) {
// If the current rename candidate contains exactly one semantically equal index,
// we can safely rename it.
// Otherwise it is unclear if a rename action is really intended,
// therefore we let those ambiguous indexes be added/dropped.
if (count($candidateIndexes) !== 1) {
continue;
}
[$removedIndex, $addedIndex] = $candidateIndexes[0];
$removedIndexName = strtolower($removedIndex->getName());
$addedIndexName = strtolower($addedIndex->getName());
if (isset($tableDifferences->renamedIndexes[$removedIndexName])) {
continue;
}
$tableDifferences->renamedIndexes[$removedIndexName] = $addedIndex;
unset(
$tableDifferences->addedIndexes[$addedIndexName],
$tableDifferences->removedIndexes[$removedIndexName]
);
}
}
/**
* @return bool
*/
public function diffForeignKey(ForeignKeyConstraint $key1, ForeignKeyConstraint $key2)
{
if (
array_map('strtolower', $key1->getUnquotedLocalColumns())
!== array_map('strtolower', $key2->getUnquotedLocalColumns())
) {
return true;
}
if (
array_map('strtolower', $key1->getUnquotedForeignColumns())
!== array_map('strtolower', $key2->getUnquotedForeignColumns())
) {
return true;
}
if ($key1->getUnqualifiedForeignTableName() !== $key2->getUnqualifiedForeignTableName()) {
return true;
}
if ($key1->onUpdate() !== $key2->onUpdate()) {
return true;
}
return $key1->onDelete() !== $key2->onDelete();
}
/**
* Returns the difference between the columns
*
* If there are differences this method returns $field2, otherwise the
* boolean false.
*
* @return string[]
*/
public function diffColumn(Column $column1, Column $column2)
{
$properties1 = $column1->toArray();
$properties2 = $column2->toArray();
$changedProperties = [];
if (get_class($properties1['type']) !== get_class($properties2['type'])) {
$changedProperties[] = 'type';
}
foreach (['notnull', 'unsigned', 'autoincrement'] as $property) {
if ($properties1[$property] === $properties2[$property]) {
continue;
}
$changedProperties[] = $property;
}
// Null values need to be checked additionally as they tell whether to create or drop a default value.
// null != 0, null != false, null != '' etc. This affects platform's table alteration SQL generation.
if (
($properties1['default'] === null) !== ($properties2['default'] === null)
|| $properties1['default'] != $properties2['default']
) {
$changedProperties[] = 'default';
}
if (
($properties1['type'] instanceof Types\StringType && ! $properties1['type'] instanceof Types\GuidType) ||
$properties1['type'] instanceof Types\BinaryType
) {
// check if value of length is set at all, default value assumed otherwise.
$length1 = $properties1['length'] ?? 255;
$length2 = $properties2['length'] ?? 255;
if ($length1 !== $length2) {
$changedProperties[] = 'length';
}
if ($properties1['fixed'] !== $properties2['fixed']) {
$changedProperties[] = 'fixed';
}
} elseif ($properties1['type'] instanceof Types\DecimalType) {
if (($properties1['precision'] ?? 10) !== ($properties2['precision'] ?? 10)) {
$changedProperties[] = 'precision';
}
if ($properties1['scale'] !== $properties2['scale']) {
$changedProperties[] = 'scale';
}
}
// A null value and an empty string are actually equal for a comment so they should not trigger a change.
if (
$properties1['comment'] !== $properties2['comment'] &&
! ($properties1['comment'] === null && $properties2['comment'] === '') &&
! ($properties2['comment'] === null && $properties1['comment'] === '')
) {
$changedProperties[] = 'comment';
}
$customOptions1 = $column1->getCustomSchemaOptions();
$customOptions2 = $column2->getCustomSchemaOptions();
foreach (array_merge(array_keys($customOptions1), array_keys($customOptions2)) as $key) {
if (! array_key_exists($key, $properties1) || ! array_key_exists($key, $properties2)) {
$changedProperties[] = $key;
} elseif ($properties1[$key] !== $properties2[$key]) {
$changedProperties[] = $key;
}
}
$platformOptions1 = $column1->getPlatformOptions();
$platformOptions2 = $column2->getPlatformOptions();
foreach (array_keys(array_intersect_key($platformOptions1, $platformOptions2)) as $key) {
if ($properties1[$key] === $properties2[$key]) {
continue;
}
$changedProperties[] = $key;
}
return array_unique($changedProperties);
}
/**
* Finds the difference between the indexes $index1 and $index2.
*
* Compares $index1 with $index2 and returns $index2 if there are any
* differences or false in case there are no differences.
*
* @return bool
*/
public function diffIndex(Index $index1, Index $index2)
{
return ! ($index1->isFullfilledBy($index2) && $index2->isFullfilledBy($index1));
}
}