Doctrine\DBAL\Platforms\OraclePlatform

Complexity

Total Complexity

160

Size/Duplication

Total Lines	1167
Duplicated Lines	0 %

Coupling/Cohesion

Components	3
Dependencies	7

Test Coverage

Coverage

89.58%

Importance

Changes

0

74 Methods

Rating	Name	Duplication	Size	Complexity
A	getListTableIndexesSQL()	0	33	1
A	getListTablesSQL()	0	4	1
A	getListViewsSQL()	0	4	1
A	getCreateViewSQL()	0	4	1
A	getDropViewSQL()	0	4	1
A	assertValidIdentifier()	0	6	2
A	getSubstringExpression()	0	8	2
A	getNowExpression()	0	10	4
A	getLocateExpression()	0	8	2
B	getDateArithmeticIntervalExpression()	0	42	10
A	getDateDiffExpression()	0	4	1
A	getBitAndComparisonExpression()	0	4	1
A	getCurrentDatabaseExpression()	0	4	1
A	getBitOrComparisonExpression()	0	6	1
A	getCreateSequenceSQL()	0	8	1
A	getAlterSequenceSQL()	0	6	1
A	getSequenceCacheSQL()	0	16	4
A	getSequenceNextValSQL()	0	4	1
A	getSetTransactionIsolationSQL()	0	4	1
A	_getTransactionIsolationLevelSQL()	0	14	5
A	getBooleanTypeDeclarationSQL()	0	4	1
A	getIntegerTypeDeclarationSQL()	0	4	1
A	getBigIntTypeDeclarationSQL()	0	4	1
A	getSmallIntTypeDeclarationSQL()	0	4	1
A	getDateTimeTypeDeclarationSQL()	0	4	1
A	getDateTimeTzTypeDeclarationSQL()	0	4	1
A	getDateTypeDeclarationSQL()	0	4	1
A	getTimeTypeDeclarationSQL()	0	4	1
A	_getCommonIntegerTypeDeclarationSQL()	0	4	1
A	getVarcharTypeDeclarationSQLSnippet()	0	8	2
A	getBinaryTypeDeclarationSQLSnippet()	0	8	2
A	getVarbinaryTypeDeclarationSQLSnippet()	0	4	1
A	getClobTypeDeclarationSQL()	0	4	1
A	getListDatabasesSQL()	0	4	1
A	getListSequencesSQL()	0	7	1
B	_getCreateTableSQL()	0	26	7
B	getCreateAutoincrementSql()	0	56	3
A	getDropAutoincrementSql()	0	15	2
A	normalizeIdentifier()	0	6	2
A	getAutoincrementIdentifierName()	0	8	2
A	getListTableForeignKeysSQL()	0	28	1
A	getListTableConstraintsSQL()	0	7	1
A	getListTableColumnsSQL()	0	40	3
A	getDropSequenceSQL()	0	8	2
A	getDropForeignKeySQL()	0	15	3
A	getAdvancedForeignKeyOptionsSQL()	0	10	3
A	getForeignKeyReferentialActionSQL()	0	20	5
A	getDropDatabaseSQL()	0	4	1
F	getAlterTableSQL()	0	127	22
B	getColumnDeclarationSQL()	0	25	8
A	getRenameIndexSQL()	0	9	2
A	prefersSequences()	0	4	1
A	usesSequenceEmulatedIdentityColumns()	0	4	1
A	getIdentitySequenceName()	0	15	2
A	supportsCommentOnStatement()	0	4	1
A	getName()	0	4	1
B	doModifyLimitQuery()	0	30	8
A	getSQLResultCasing()	0	4	1
A	getCreateTemporaryTableSnippetSQL()	0	4	1
A	getDateTimeTzFormatString()	0	4	1
A	getDateFormatString()	0	4	1
A	getTimeFormatString()	0	4	1
A	fixSchemaElementName()	0	9	2
A	getMaxIdentifierLength()	0	4	1
A	supportsSequences()	0	4	1
A	supportsForeignKeyOnUpdate()	0	4	1
A	supportsReleaseSavepoints()	0	4	1
A	getTruncateTableSQL()	0	6	1
A	getDummySelectSQL()	0	4	1
A	initializeDoctrineTypeMappings()	0	28	1
A	releaseSavePoint()	0	4	1
A	getReservedKeywordsClass()	0	4	1
A	getBlobTypeDeclarationSQL()	0	4	1
A	getListTableCommentsSQL()	0	20	3

<?php

declare(strict_types=1);

namespace Doctrine\DBAL\Platforms;

use Doctrine\DBAL\DBALException;
use Doctrine\DBAL\Exception\ColumnLengthRequired;
use Doctrine\DBAL\Schema\ForeignKeyConstraint;
use Doctrine\DBAL\Schema\Identifier;
use Doctrine\DBAL\Schema\Index;
use Doctrine\DBAL\Schema\Sequence;
use Doctrine\DBAL\Schema\Table;
use Doctrine\DBAL\Schema\TableDiff;
use Doctrine\DBAL\TransactionIsolationLevel;
use Doctrine\DBAL\Types\BinaryType;
use InvalidArgumentException;
use function array_merge;
use function count;
use function explode;
use function implode;
use function preg_match;
use function sprintf;
use function strlen;
use function strpos;
use function strtoupper;
use function substr;

/**
 * OraclePlatform.
 */
class OraclePlatform extends AbstractPlatform
{
    /**
     * Assertion for Oracle identifiers.
     *
     * @link http://docs.oracle.com/cd/B19306_01/server.102/b14200/sql_elements008.htm
     *
     * @throws DBALException
     */
    public static function assertValidIdentifier(string $identifier) : void
    {
        if (! preg_match('(^(([a-zA-Z]{1}[a-zA-Z0-9_$#]{0,})|("[^"]+"))$)', $identifier)) {
            throw new DBALException('Invalid Oracle identifier.');
        }
    }

    /**
     * {@inheritDoc}
     */
    public function getSubstringExpression(string $string, string $start, ?string $length = null) : string
    {
        if ($length === null) {
            return sprintf('SUBSTR(%s, %s)', $string, $start);
        }

        return sprintf('SUBSTR(%s, %s, %s)', $string, $start, $length);
    }

    /**
     * {@inheritDoc}
     */
    public function getNowExpression(string $type = 'timestamp') : string
    {
        switch ($type) {
            case 'date':
            case 'time':
            case 'timestamp':
            default:
                return 'TO_CHAR(CURRENT_TIMESTAMP, \'YYYY-MM-DD HH24:MI:SS\')';
        }
    }

    /**
     * {@inheritDoc}
     */
    public function getLocateExpression(string $string, string $substring, ?string $start = null) : string
    {
        if ($start === null) {
            return sprintf('INSTR(%s, %s)', $string, $substring);
        }

        return sprintf('INSTR(%s, %s, %s)', $string, $substring, $start);
    }

    /**
     * {@inheritdoc}
     */
    protected function getDateArithmeticIntervalExpression(string $date, string $operator, string $interval, string $unit) : string
    {
        switch ($unit) {
            case DateIntervalUnit::MONTH:
            case DateIntervalUnit::QUARTER:
            case DateIntervalUnit::YEAR:
                switch ($unit) {
                    case DateIntervalUnit::QUARTER:
                        $interval = $this->multiplyInterval($interval, 3);
                        break;

                    case DateIntervalUnit::YEAR:
                        $interval = $this->multiplyInterval($interval, 12);
                        break;
                }

                return 'ADD_MONTHS(' . $date . ', ' . $operator . $interval . ')';

            default:
                $calculationClause = '';

                switch ($unit) {
                    case DateIntervalUnit::SECOND:
                        $calculationClause = '/24/60/60';
                        break;

                    case DateIntervalUnit::MINUTE:
                        $calculationClause = '/24/60';
                        break;

                    case DateIntervalUnit::HOUR:
                        $calculationClause = '/24';
                        break;

                    case DateIntervalUnit::WEEK:
                        $calculationClause = '*7';
                        break;
                }

                return '(' . $date . $operator . $interval . $calculationClause . ')';
        }
    }

    /**
     * {@inheritDoc}
     */
    public function getDateDiffExpression(string $date1, string $date2) : string
    {
        return sprintf('TRUNC(%s) - TRUNC(%s)', $date1, $date2);
    }

    /**
     * {@inheritDoc}
     */
    public function getBitAndComparisonExpression(string $value1, string $value2) : string
    {
        return 'BITAND(' . $value1 . ', ' . $value2 . ')';
    }

    /**
     * {@inheritDoc}
     */
    public function getCurrentDatabaseExpression() : string
    {
        return "SYS_CONTEXT('USERENV', 'CURRENT_SCHEMA')";
    }

    /**
     * {@inheritDoc}
     */
    public function getBitOrComparisonExpression(string $value1, string $value2) : string
    {
        return '(' . $value1 . '-' .
                $this->getBitAndComparisonExpression($value1, $value2)
                . '+' . $value2 . ')';
    }

    /**
     * {@inheritDoc}
     *
     * Need to specifiy minvalue, since start with is hidden in the system and MINVALUE <= START WITH.
     * Therefore we can use MINVALUE to be able to get a hint what START WITH was for later introspection
     * in {@see listSequences()}
     */
    public function getCreateSequenceSQL(Sequence $sequence) : string
    {
        return 'CREATE SEQUENCE ' . $sequence->getQuotedName($this) .
               ' START WITH ' . $sequence->getInitialValue() .
               ' MINVALUE ' . $sequence->getInitialValue() .
               ' INCREMENT BY ' . $sequence->getAllocationSize() .
               $this->getSequenceCacheSQL($sequence);
    }

    /**
     * {@inheritDoc}
     */
    public function getAlterSequenceSQL(Sequence $sequence) : string
    {
        return 'ALTER SEQUENCE ' . $sequence->getQuotedName($this) .
               ' INCREMENT BY ' . $sequence->getAllocationSize()
               . $this->getSequenceCacheSQL($sequence);
    }

    /**
     * Cache definition for sequences
     */
    private function getSequenceCacheSQL(Sequence $sequence) : string
    {
        if ($sequence->getCache() === 0) {
            return ' NOCACHE';
        }

        if ($sequence->getCache() === 1) {
            return ' NOCACHE';
        }

        if ($sequence->getCache() > 1) {
            return ' CACHE ' . $sequence->getCache();
        }

        return '';
    }

    /**
     * {@inheritDoc}
     */
    public function getSequenceNextValSQL(string $sequenceName) : string
    {
        return 'SELECT ' . $sequenceName . '.nextval FROM DUAL';
    }

    /**
     * {@inheritDoc}
     */
    public function getSetTransactionIsolationSQL(int $level) : string
    {
        return 'SET TRANSACTION ISOLATION LEVEL ' . $this->_getTransactionIsolationLevelSQL($level);
    }

    /**
     * {@inheritDoc}
     */
    protected function _getTransactionIsolationLevelSQL(int $level) : string
    {
        switch ($level) {
            case TransactionIsolationLevel::READ_UNCOMMITTED:
                return 'READ UNCOMMITTED';
            case TransactionIsolationLevel::READ_COMMITTED:
                return 'READ COMMITTED';
            case TransactionIsolationLevel::REPEATABLE_READ:
            case TransactionIsolationLevel::SERIALIZABLE:
                return 'SERIALIZABLE';
            default:
                return parent::_getTransactionIsolationLevelSQL($level);
        }
    }

    /**
     * {@inheritDoc}
     */
    public function getBooleanTypeDeclarationSQL(array $columnDef) : string
    {
        return 'NUMBER(1)';
    }

    /**
     * {@inheritDoc}
     */
    public function getIntegerTypeDeclarationSQL(array $columnDef) : string
    {
        return 'NUMBER(10)';
    }

    /**
     * {@inheritDoc}
     */
    public function getBigIntTypeDeclarationSQL(array $columnDef) : string
    {
        return 'NUMBER(20)';
    }

    /**
     * {@inheritDoc}
     */
    public function getSmallIntTypeDeclarationSQL(array $columnDef) : string
    {
        return 'NUMBER(5)';
    }

    /**
     * {@inheritDoc}
     */
    public function getDateTimeTypeDeclarationSQL(array $fieldDeclaration) : string
    {
        return 'TIMESTAMP(0)';
    }

    /**
     * {@inheritDoc}
     */
    public function getDateTimeTzTypeDeclarationSQL(array $fieldDeclaration) : string
    {
        return 'TIMESTAMP(0) WITH TIME ZONE';
    }

    /**
     * {@inheritDoc}
     */
    public function getDateTypeDeclarationSQL(array $fieldDeclaration) : string
    {
        return 'DATE';
    }

    /**
     * {@inheritDoc}
     */
    public function getTimeTypeDeclarationSQL(array $fieldDeclaration) : string
    {
        return 'DATE';
    }

    /**
     * {@inheritDoc}
     */
    protected function _getCommonIntegerTypeDeclarationSQL(array $columnDef) : string
    {
        return '';
    }

    /**
     * {@inheritDoc}
     */
    protected function getVarcharTypeDeclarationSQLSnippet(?int $length) : string
    {
        if ($length === null) {
            throw ColumnLengthRequired::new($this, 'VARCHAR2');
        }

        return sprintf('VARCHAR2(%d)', $length);
    }

    /**
     * {@inheritDoc}
     */
    protected function getBinaryTypeDeclarationSQLSnippet(?int $length) : string
    {
        if ($length === null) {
            throw ColumnLengthRequired::new($this, 'RAW');
        }

        return sprintf('RAW(%d)', $length);
    }

    /**
     * {@inheritDoc}
     */
    protected function getVarbinaryTypeDeclarationSQLSnippet(?int $length) : string
    {
        return $this->getBinaryTypeDeclarationSQLSnippet($length);
    }

    /**
     * {@inheritDoc}
     */
    public function getClobTypeDeclarationSQL(array $field) : string
    {
        return 'CLOB';
    }

    /**
     * {@inheritDoc}
     */
    public function getListDatabasesSQL() : string
    {
        return 'SELECT username FROM all_users';
    }

    /**
     * {@inheritDoc}
     */
    public function getListSequencesSQL(string $database) : string
    {
        return 'SELECT SEQUENCE_NAME, MIN_VALUE, INCREMENT_BY FROM SYS.ALL_SEQUENCES WHERE SEQUENCE_OWNER = '
            . $this->quoteStringLiteral(
                $this->normalizeIdentifier($database)->getName()
            );
    }

    /**
     * {@inheritDoc}
     */
    protected function _getCreateTableSQL(string $tableName, array $columns, array $options = []) : array
    {
        $indexes            = $options['indexes'] ?? [];
        $options['indexes'] = [];
        $sql                = parent::_getCreateTableSQL($tableName, $columns, $options);

        foreach ($columns as $column) {
            if (isset($column['sequence'])) {
                $sql[] = $this->getCreateSequenceSQL($column['sequence']);
            }

            if (empty($column['autoincrement'])) {
                continue;
            }

            $sql = array_merge($sql, $this->getCreateAutoincrementSql($column['name'], $tableName));
        }

        if (isset($indexes) && ! empty($indexes)) {
            foreach ($indexes as $index) {
                $sql[] = $this->getCreateIndexSQL($index, $tableName);
            }
        }

        return $sql;
    }

    /**
     * {@inheritDoc}
     *
     * @link http://ezcomponents.org/docs/api/trunk/DatabaseSchema/ezcDbSchemaOracleReader.html
     */
    public function getListTableIndexesSQL(string $table, ?string $currentDatabase = null) : string
    {
        $table = $this->normalizeIdentifier($table);
        $table = $this->quoteStringLiteral($table->getName());

        return "SELECT uind_col.index_name AS name,
                       (
                           SELECT uind.index_type
                           FROM   user_indexes uind
                           WHERE  uind.index_name = uind_col.index_name
                       ) AS type,
                       decode(
                           (
                               SELECT uind.uniqueness
                               FROM   user_indexes uind
                               WHERE  uind.index_name = uind_col.index_name
                           ),
                           'NONUNIQUE',
                           0,
                           'UNIQUE',
                           1
                       ) AS is_unique,
                       uind_col.column_name AS column_name,
                       uind_col.column_position AS column_pos,
                       (
                           SELECT ucon.constraint_type
                           FROM   user_constraints ucon
                           WHERE  ucon.index_name = uind_col.index_name
                       ) AS is_primary
             FROM      user_ind_columns uind_col
             WHERE     uind_col.table_name = " . $table . '
             ORDER BY  uind_col.column_position ASC';
    }

    /**
     * {@inheritDoc}
     */
    public function getListTablesSQL() : string
    {
        return 'SELECT * FROM sys.user_tables';
    }

    /**
     * {@inheritDoc}
     */
    public function getListViewsSQL(string $database) : string
    {
        return 'SELECT view_name, text FROM sys.user_views';
    }

    /**
     * {@inheritDoc}
     */
    public function getCreateViewSQL(string $name, string $sql) : string
    {
        return 'CREATE VIEW ' . $name . ' AS ' . $sql;
    }

    /**
     * {@inheritDoc}
     */
    public function getDropViewSQL(string $name) : string
    {
        return 'DROP VIEW ' . $name;
    }

    /**
     * @return array<int, string>

The doc-type array<int, could not be parsed: Expected ">" at position 5, but found "end of type". (view supported doc-types)

     */
    public function getCreateAutoincrementSql(string $name, string $table, int $start = 1) : array
    {
        $tableIdentifier   = $this->normalizeIdentifier($table);
        $quotedTableName   = $tableIdentifier->getQuotedName($this);
        $unquotedTableName = $tableIdentifier->getName();

        $nameIdentifier = $this->normalizeIdentifier($name);
        $quotedName     = $nameIdentifier->getQuotedName($this);
        $unquotedName   = $nameIdentifier->getName();

        $sql = [];

        $autoincrementIdentifierName = $this->getAutoincrementIdentifierName($tableIdentifier);

        $idx = new Index($autoincrementIdentifierName, [$quotedName], true, true);

        $sql[] = 'DECLARE
  constraints_Count NUMBER;
BEGIN
  SELECT COUNT(CONSTRAINT_NAME) INTO constraints_Count FROM USER_CONSTRAINTS WHERE TABLE_NAME = \'' . $unquotedTableName . '\' AND CONSTRAINT_TYPE = \'P\';
  IF constraints_Count = 0 OR constraints_Count = \'\' THEN
    EXECUTE IMMEDIATE \'' . $this->getCreateConstraintSQL($idx, $quotedTableName) . '\';
  END IF;
END;';

        $sequenceName = $this->getIdentitySequenceName(
            $tableIdentifier->isQuoted() ? $quotedTableName : $unquotedTableName,
            $nameIdentifier->isQuoted() ? $quotedName : $unquotedName
        );
        $sequence     = new Sequence($sequenceName, $start);
        $sql[]        = $this->getCreateSequenceSQL($sequence);

        $sql[] = 'CREATE TRIGGER ' . $autoincrementIdentifierName . '
   BEFORE INSERT
   ON ' . $quotedTableName . '
   FOR EACH ROW
DECLARE
   last_Sequence NUMBER;
   last_InsertID NUMBER;
BEGIN
   SELECT ' . $sequenceName . '.NEXTVAL INTO :NEW.' . $quotedName . ' FROM DUAL;
   IF (:NEW.' . $quotedName . ' IS NULL OR :NEW.' . $quotedName . ' = 0) THEN
      SELECT ' . $sequenceName . '.NEXTVAL INTO :NEW.' . $quotedName . ' FROM DUAL;
   ELSE
      SELECT NVL(Last_Number, 0) INTO last_Sequence
        FROM User_Sequences
       WHERE Sequence_Name = \'' . $sequence->getName() . '\';
      SELECT :NEW.' . $quotedName . ' INTO last_InsertID FROM DUAL;
      WHILE (last_InsertID > last_Sequence) LOOP
         SELECT ' . $sequenceName . '.NEXTVAL INTO last_Sequence FROM DUAL;
      END LOOP;
   END IF;
END;';

        return $sql;
    }

    /**
     * Returns the SQL statements to drop the autoincrement for the given table name.
     *
     * @param string $table The table name to drop the autoincrement for.
     *
     * @return string[]
     */
    public function getDropAutoincrementSql(string $table) : array
    {
        $table                       = $this->normalizeIdentifier($table);
        $autoincrementIdentifierName = $this->getAutoincrementIdentifierName($table);
        $identitySequenceName        = $this->getIdentitySequenceName(
            $table->isQuoted() ? $table->getQuotedName($this) : $table->getName(),
            ''
        );

        return [
            'DROP TRIGGER ' . $autoincrementIdentifierName,
            $this->getDropSequenceSQL($identitySequenceName),
            $this->getDropConstraintSQL($autoincrementIdentifierName, $table->getQuotedName($this)),
        ];
    }

    /**
     * Normalizes the given identifier.
     *
     * Uppercases the given identifier if it is not quoted by intention
     * to reflect Oracle's internal auto uppercasing strategy of unquoted identifiers.
     *
     * @param string $name The identifier to normalize.
     *
     * @return Identifier The normalized identifier.
     */
    private function normalizeIdentifier(string $name) : Identifier
    {
        $identifier = new Identifier($name);

        return $identifier->isQuoted() ? $identifier : new Identifier(strtoupper($name));
    }

    /**
     * Returns the autoincrement primary key identifier name for the given table identifier.
     *
     * Quotes the autoincrement primary key identifier name
     * if the given table name is quoted by intention.
     *
     * @param Identifier $table The table identifier to return the autoincrement primary key identifier name for.
     */
    private function getAutoincrementIdentifierName(Identifier $table) : string
    {
        $identifierName = $table->getName() . '_AI_PK';

        return $table->isQuoted()
            ? $this->quoteSingleIdentifier($identifierName)
            : $identifierName;
    }

    /**
     * {@inheritDoc}
     */
    public function getListTableForeignKeysSQL(string $table, ?string $database = null) : string
    {
        $table = $this->normalizeIdentifier($table);
        $table = $this->quoteStringLiteral($table->getName());

        return "SELECT alc.constraint_name,
          alc.DELETE_RULE,
          cols.column_name \"local_column\",
          cols.position,
          (
              SELECT r_cols.table_name
              FROM   user_cons_columns r_cols
              WHERE  alc.r_constraint_name = r_cols.constraint_name
              AND    r_cols.position = cols.position
          ) AS \"references_table\",
          (
              SELECT r_cols.column_name
              FROM   user_cons_columns r_cols
              WHERE  alc.r_constraint_name = r_cols.constraint_name
              AND    r_cols.position = cols.position
          ) AS \"foreign_column\"
     FROM user_cons_columns cols
     JOIN user_constraints alc
       ON alc.constraint_name = cols.constraint_name
      AND alc.constraint_type = 'R'
      AND alc.table_name = " . $table . '
    ORDER BY cols.constraint_name ASC, cols.position ASC';
    }

    /**
     * {@inheritDoc}
     */
    public function getListTableConstraintsSQL(string $table) : string
    {
        $table = $this->normalizeIdentifier($table);
        $table = $this->quoteStringLiteral($table->getName());

        return 'SELECT * FROM user_constraints WHERE table_name = ' . $table;
    }

    /**
     * {@inheritDoc}
     */
    public function getListTableColumnsSQL(string $table, ?string $database = null) : string
    {
        $table = $this->normalizeIdentifier($table);
        $table = $this->quoteStringLiteral($table->getName());

        $tabColumnsTableName       = 'user_tab_columns';
        $colCommentsTableName      = 'user_col_comments';
        $tabColumnsOwnerCondition  = '';
        $colCommentsOwnerCondition = '';

        if ($database !== null && $database !== '/') {
            $database                  = $this->normalizeIdentifier($database);
            $database                  = $this->quoteStringLiteral($database->getName());
            $tabColumnsTableName       = 'all_tab_columns';
            $colCommentsTableName      = 'all_col_comments';
            $tabColumnsOwnerCondition  = ' AND c.owner = ' . $database;
            $colCommentsOwnerCondition = ' AND d.OWNER = c.OWNER';
        }

        return sprintf(
            <<<'SQL'
SELECT   c.*,
         (
             SELECT d.comments
             FROM   %s d
             WHERE  d.TABLE_NAME = c.TABLE_NAME%s
             AND    d.COLUMN_NAME = c.COLUMN_NAME
         ) AS comments
FROM     %s c
WHERE    c.table_name = %s%s
ORDER BY c.column_id
SQL
            ,
            $colCommentsTableName,
            $colCommentsOwnerCondition,
            $tabColumnsTableName,
            $table,
            $tabColumnsOwnerCondition
        );
    }

    /**
     * {@inheritDoc}
     */
    public function getDropSequenceSQL($sequence) : string
    {
        if ($sequence instanceof Sequence) {
            $sequence = $sequence->getQuotedName($this);
        }

        return 'DROP SEQUENCE ' . $sequence;
    }

    /**
     * {@inheritDoc}
     */
    public function getDropForeignKeySQL($foreignKey, $table) : string
    {
        if (! $foreignKey instanceof ForeignKeyConstraint) {
            $foreignKey = new Identifier($foreignKey);
        }

        if (! $table instanceof Table) {
            $table = new Identifier($table);
        }

        $foreignKey = $foreignKey->getQuotedName($this);
        $table      = $table->getQuotedName($this);

        return 'ALTER TABLE ' . $table . ' DROP CONSTRAINT ' . $foreignKey;
    }

    /**
     * {@inheritdoc}
     */
    public function getAdvancedForeignKeyOptionsSQL(ForeignKeyConstraint $foreignKey) : string
    {
        $referentialAction = null;

        if ($foreignKey->hasOption('onDelete')) {
            $referentialAction = $this->getForeignKeyReferentialActionSQL($foreignKey->getOption('onDelete'));
        }

        return $referentialAction ? ' ON DELETE ' . $referentialAction : '';
    }

    /**
     * {@inheritdoc}
     */
    public function getForeignKeyReferentialActionSQL(string $action) : string
    {
        $action = strtoupper($action);

        switch ($action) {
            case 'RESTRICT': // RESTRICT is not supported, therefore falling back to NO ACTION.
            case 'NO ACTION':
                // NO ACTION cannot be declared explicitly,
                // therefore returning empty string to indicate to OMIT the referential clause.
                return '';

            case 'CASCADE':
            case 'SET NULL':
                return $action;

            default:
                // SET DEFAULT is not supported, throw exception instead.
                throw new InvalidArgumentException(sprintf('Invalid foreign key action "%s".', $action));
        }
    }

    /**
     * {@inheritDoc}
     */
    public function getDropDatabaseSQL(string $database) : string
    {
        return 'DROP USER ' . $database . ' CASCADE';
    }

    /**
     * {@inheritDoc}
     */
    public function getAlterTableSQL(TableDiff $diff) : array
    {
        $sql         = [];
        $commentsSQL = [];
        $columnSql   = [];

        $fields = [];

        foreach ($diff->addedColumns as $column) {
            if ($this->onSchemaAlterTableAddColumn($column, $diff, $columnSql)) {
                continue;
            }

            $fields[] = $this->getColumnDeclarationSQL($column->getQuotedName($this), $column->toArray());
            $comment  = $this->getColumnComment($column);

            if (! $comment) {

The expression $comment of type string|null is loosely compared to false; this is ambiguous if the string can be empty. You might want to explicitly use === null instead.

                continue;
            }

            $commentsSQL[] = $this->getCommentOnColumnSQL(
                $diff->getName($this)->getQuotedName($this),
                $column->getQuotedName($this),
                $comment
            );
        }

        if (count($fields)) {
            $sql[] = 'ALTER TABLE ' . $diff->getName($this)->getQuotedName($this) . ' ADD (' . implode(', ', $fields) . ')';
        }

        $fields = [];
        foreach ($diff->changedColumns as $columnDiff) {
            if ($this->onSchemaAlterTableChangeColumn($columnDiff, $diff, $columnSql)) {
                continue;
            }

            $column = $columnDiff->column;

            // Do not generate column alteration clause if type is binary and only fixed property has changed.
            // Oracle only supports binary type columns with variable length.
            // Avoids unnecessary table alteration statements.
            if ($column->getType() instanceof BinaryType &&
                $columnDiff->hasChanged('fixed') &&
                count($columnDiff->changedProperties) === 1
            ) {
                continue;
            }

            $columnHasChangedComment = $columnDiff->hasChanged('comment');

            /**
             * Do not add query part if only comment has changed
             */
            if (! ($columnHasChangedComment && count($columnDiff->changedProperties) === 1)) {
                $columnInfo = $column->toArray();

                if (! $columnDiff->hasChanged('notnull')) {
                    unset($columnInfo['notnull']);
                }

                $fields[] = $column->getQuotedName($this) . $this->getColumnDeclarationSQL('', $columnInfo);
            }

            if (! $columnHasChangedComment) {
                continue;
            }

            $commentsSQL[] = $this->getCommentOnColumnSQL(
                $diff->getName($this)->getQuotedName($this),
                $column->getQuotedName($this),
                $this->getColumnComment($column)
            );
        }

        if (count($fields)) {
            $sql[] = 'ALTER TABLE ' . $diff->getName($this)->getQuotedName($this) . ' MODIFY (' . implode(', ', $fields) . ')';
        }

        foreach ($diff->renamedColumns as $oldColumnName => $column) {
            if ($this->onSchemaAlterTableRenameColumn($oldColumnName, $column, $diff, $columnSql)) {
                continue;
            }

            $oldColumnName = new Identifier($oldColumnName);

            $sql[] = 'ALTER TABLE ' . $diff->getName($this)->getQuotedName($this) .
                ' RENAME COLUMN ' . $oldColumnName->getQuotedName($this) . ' TO ' . $column->getQuotedName($this);
        }

        $fields = [];
        foreach ($diff->removedColumns as $column) {
            if ($this->onSchemaAlterTableRemoveColumn($column, $diff, $columnSql)) {
                continue;
            }

            $fields[] = $column->getQuotedName($this);
        }

        if (count($fields)) {
            $sql[] = 'ALTER TABLE ' . $diff->getName($this)->getQuotedName($this) . ' DROP (' . implode(', ', $fields) . ')';
        }

        $tableSql = [];

        if (! $this->onSchemaAlterTable($diff, $tableSql)) {
            $sql = array_merge($sql, $commentsSQL);

            $newName = $diff->getNewName();

            if ($newName !== null) {
                $sql[] = sprintf(
                    'ALTER TABLE %s RENAME TO %s',
                    $diff->getName($this)->getQuotedName($this),
                    $newName->getQuotedName($this)
                );
            }

            $sql = array_merge(
                $this->getPreAlterTableIndexForeignKeySQL($diff),
                $sql,
                $this->getPostAlterTableIndexForeignKeySQL($diff)
            );
        }

        return array_merge($sql, $tableSql, $columnSql);
    }

    /**
     * {@inheritdoc}
     */
    public function getColumnDeclarationSQL(string $name, array $field) : string
    {
        if (isset($field['columnDefinition'])) {
            $columnDef = $this->getCustomTypeDeclarationSQL($field);
        } else {
            $default = $this->getDefaultValueDeclarationSQL($field);

            $notnull = '';

            if (isset($field['notnull'])) {
                $notnull = $field['notnull'] ? ' NOT NULL' : ' NULL';
            }

            $unique = isset($field['unique']) && $field['unique'] ?
                ' ' . $this->getUniqueFieldDeclarationSQL() : '';

            $check = isset($field['check']) && $field['check'] ?
                ' ' . $field['check'] : '';

            $typeDecl  = $field['type']->getSQLDeclaration($field, $this);
            $columnDef = $typeDecl . $default . $notnull . $unique . $check;
        }

        return $name . ' ' . $columnDef;
    }

    /**
     * {@inheritdoc}
     */
    protected function getRenameIndexSQL(string $oldIndexName, Index $index, string $tableName) : array
    {
        if (strpos($tableName, '.') !== false) {
            [$schema]     = explode('.', $tableName);

The variable $schema does not exist. Did you forget to declare it?

            $oldIndexName = $schema . '.' . $oldIndexName;
        }

        return ['ALTER INDEX ' . $oldIndexName . ' RENAME TO ' . $index->getQuotedName($this)];
    }

    /**
     * {@inheritDoc}
     */
    public function prefersSequences() : bool
    {
        return true;
    }

    /**
     * {@inheritdoc}
     */
    public function usesSequenceEmulatedIdentityColumns() : bool
    {
        return true;
    }

    /**
     * {@inheritdoc}
     */
    public function getIdentitySequenceName(string $tableName, string $columnName) : string
    {
        $table = new Identifier($tableName);

        // No usage of column name to preserve BC compatibility with <2.5
        $identitySequenceName = $table->getName() . '_SEQ';

        if ($table->isQuoted()) {
            $identitySequenceName = '"' . $identitySequenceName . '"';
        }

        $identitySequenceIdentifier = $this->normalizeIdentifier($identitySequenceName);

        return $identitySequenceIdentifier->getQuotedName($this);
    }

    /**
     * {@inheritDoc}
     */
    public function supportsCommentOnStatement() : bool
    {
        return true;
    }

    /**
     * {@inheritDoc}
     */
    public function getName() : string
    {
        return 'oracle';
    }

    /**
     * {@inheritDoc}
     */
    protected function doModifyLimitQuery(string $query, ?int $limit, int $offset) : string
    {
        if ($limit === null && $offset <= 0) {
            return $query;
        }

        if (preg_match('/^\s*SELECT/i', $query)) {
            if (! preg_match('/\sFROM\s/i', $query)) {
                $query .= ' FROM dual';
            }

            $columns = ['a.*'];

            if ($offset > 0) {
                $columns[] = 'ROWNUM AS doctrine_rownum';
            }

            $query = sprintf('SELECT %s FROM (%s) a', implode(', ', $columns), $query);

            if ($limit !== null) {
                $query .= sprintf(' WHERE ROWNUM <= %d', $offset + $limit);
            }

            if ($offset > 0) {
                $query = sprintf('SELECT * FROM (%s) WHERE doctrine_rownum >= %d', $query, $offset + 1);
            }
        }

        return $query;
    }

    /**
     * {@inheritDoc}
     *
     * Oracle returns all column names in SQL result sets in uppercase.
     */
    public function getSQLResultCasing(string $column) : string
    {
        return strtoupper($column);
    }

    /**
     * {@inheritDoc}
     */
    public function getCreateTemporaryTableSnippetSQL() : string
    {
        return 'CREATE GLOBAL TEMPORARY TABLE';
    }

    /**
     * {@inheritDoc}
     */
    public function getDateTimeTzFormatString() : string
    {
        return 'Y-m-d H:i:sP';
    }

    /**
     * {@inheritDoc}
     */
    public function getDateFormatString() : string
    {
        return 'Y-m-d 00:00:00';
    }

    /**
     * {@inheritDoc}
     */
    public function getTimeFormatString() : string
    {
        return '1900-01-01 H:i:s';
    }

    /**
     * {@inheritDoc}
     */
    public function fixSchemaElementName(string $schemaElementName) : string
    {
        if (strlen($schemaElementName) > 30) {
            // Trim it
            return substr($schemaElementName, 0, 30);
        }

        return $schemaElementName;
    }

    /**
     * {@inheritDoc}
     */
    public function getMaxIdentifierLength() : int
    {
        return 30;
    }

    /**
     * {@inheritDoc}
     */
    public function supportsSequences() : bool
    {
        return true;
    }

    /**
     * {@inheritDoc}
     */
    public function supportsForeignKeyOnUpdate() : bool
    {
        return false;
    }

    /**
     * {@inheritDoc}
     */
    public function supportsReleaseSavepoints() : bool
    {
        return false;
    }

    /**
     * {@inheritDoc}
     */
    public function getTruncateTableSQL(string $tableName, bool $cascade = false) : string
    {
        $tableIdentifier = new Identifier($tableName);

        return 'TRUNCATE TABLE ' . $tableIdentifier->getQuotedName($this);
    }

    /**
     * {@inheritDoc}
     */
    public function getDummySelectSQL(string $expression = '1') : string
    {
        return sprintf('SELECT %s FROM DUAL', $expression);
    }

    /**
     * {@inheritDoc}
     */
    protected function initializeDoctrineTypeMappings() : void
    {
        $this->doctrineTypeMapping = [

It seems like array('binary_double' => 'float', 'binary_float' => 'float', 'binary_integer' => 'boolean', 'blob' => 'blob', 'char' => 'string', 'clob' => 'text', 'date' => 'date', 'float' => 'float', 'integer' => 'integer', 'long' => 'string', 'long raw' => 'blob', 'nchar' => 'string', 'nclob' => 'text', 'number' => 'integer', 'nvarchar2' => 'string', 'pls_integer' => 'boolean', 'raw' => 'binary', 'rowid' => 'string', 'timestamp' => 'datetime', 'timestamptz' => 'datetimetz', 'urowid' => 'string', 'varchar' => 'string', 'varchar2' => 'string') of type array<string,string,{"binary_double":"string","binary_float":"string","binary_integer":"string","blob":"string","char":"string","clob":"string","date":"string","float":"string","integer":"string","long":"string","long raw":"string","nchar":"string","nclob":"string","number":"string","nvarchar2":"string","pls_integer":"string","raw":"string","rowid":"string","timestamp":"string","timestamptz":"string","urowid":"string","varchar":"string","varchar2":"string"}> is incompatible with the declared type array<integer,string>|null of property $doctrineTypeMapping.

            'binary_double'  => 'float',
            'binary_float'   => 'float',
            'binary_integer' => 'boolean',
            'blob'           => 'blob',
            'char'           => 'string',
            'clob'           => 'text',
            'date'           => 'date',
            'float'          => 'float',
            'integer'        => 'integer',
            'long'           => 'string',
            'long raw'       => 'blob',
            'nchar'          => 'string',
            'nclob'          => 'text',
            'number'         => 'integer',
            'nvarchar2'      => 'string',
            'pls_integer'    => 'boolean',
            'raw'            => 'binary',
            'rowid'          => 'string',
            'timestamp'      => 'datetime',
            'timestamptz'    => 'datetimetz',
            'urowid'         => 'string',
            'varchar'        => 'string',
            'varchar2'       => 'string',
        ];
    }

    /**
     * {@inheritDoc}
     */
    public function releaseSavePoint(string $savepoint) : string
    {
        return '';
    }

    /**
     * {@inheritDoc}
     */
    protected function getReservedKeywordsClass() : string
    {
        return Keywords\OracleKeywords::class;
    }

    /**
     * {@inheritDoc}
     */
    public function getBlobTypeDeclarationSQL(array $field) : string
    {
        return 'BLOB';
    }

    public function getListTableCommentsSQL(string $table, ?string $database = null) : string
    {
        $tableCommentsName = 'user_tab_comments';
        $ownerCondition    = '';

        if ($database !== null && $database !== '/') {
            $tableCommentsName = 'all_tab_comments';
            $ownerCondition    = ' AND owner = ' . $this->quoteStringLiteral($this->normalizeIdentifier($database)->getName());
        }

        return sprintf(
            <<<'SQL'
SELECT comments FROM %s WHERE table_name = %s%s
SQL
            ,
            $tableCommentsName,
            $this->quoteStringLiteral($this->normalizeIdentifier($table)->getName()),
            $ownerCondition
        );
    }
}