Schema.php

<?php

declare(strict_types=1);

namespace Yiisoft\Db\Oracle;

use Throwable;
use Yiisoft\Db\Cache\SchemaCache;
use Yiisoft\Db\Connection\ConnectionInterface;
use Yiisoft\Db\Constraint\CheckConstraint;
use Yiisoft\Db\Constraint\Constraint;
use Yiisoft\Db\Constraint\ForeignKeyConstraint;
use Yiisoft\Db\Constraint\IndexConstraint;
use Yiisoft\Db\Driver\Pdo\AbstractPdoSchema;
use Yiisoft\Db\Exception\Exception;
use Yiisoft\Db\Exception\InvalidConfigException;
use Yiisoft\Db\Exception\NotSupportedException;
use Yiisoft\Db\Expression\Expression;
use Yiisoft\Db\Helper\DbArrayHelper;
use Yiisoft\Db\Oracle\Column\BinaryColumnSchema;
use Yiisoft\Db\Schema\Builder\ColumnInterface;
use Yiisoft\Db\Schema\Column\ColumnSchemaInterface;
use Yiisoft\Db\Schema\TableSchemaInterface;

use function array_change_key_case;
use function array_map;
use function array_merge;
use function array_reverse;
use function implode;
use function is_array;
use function md5;
use function preg_match;
use function preg_replace;
use function serialize;
use function str_replace;
use function strtolower;
use function trim;

/**
 * Implements the Oracle Server specific schema, supporting Oracle Server 11C and above.
 *
 * @psalm-type ColumnInfoArray = array{
 *   column_name: string,
 *   data_type: string,
 *   data_precision: string|null,
 *   data_scale: string|null,
 *   data_length: string,
 *   nullable: string,
 *   data_default: string|null,
 *   is_pk: string|null,
 *   identity_column: string,
 *   column_comment: string|null
 * }
 *
 * @psalm-type ConstraintArray = array<
 *   array-key,
 *   array {
 *     name: string,
 *     column_name: string,
 *     type: string,
 *     foreign_table_schema: string|null,
 *     foreign_table_name: string|null,
 *     foreign_column_name: string|null,
 *     on_update: string,
 *     on_delete: string,
 *     check_expr: string
 *   }
 * >
 */
final class Schema extends AbstractPdoSchema
{
    /**
     * The mapping from physical column types (keys) to abstract column types (values).
     *
     * @link https://docs.oracle.com/en/database/oracle/oracle-database/23/sqlrf/Data-Types.html
     *
     * @var string[]
     */
    private const TYPE_MAP = [
        'char' => self::TYPE_CHAR,
        'nchar' => self::TYPE_CHAR,
        'varchar2' => self::TYPE_STRING,
        'nvarchar2' => self::TYPE_STRING,
        'clob' => self::TYPE_TEXT,
        'nclob' => self::TYPE_TEXT,
        'blob' => self::TYPE_BINARY,
        'bfile' => self::TYPE_BINARY,
        'long raw' => self::TYPE_BINARY,
        'raw' => self::TYPE_BINARY,
        'number' => self::TYPE_DECIMAL,
        'binary_float' => self::TYPE_FLOAT, // 32 bit
        'binary_double' => self::TYPE_DOUBLE, // 64 bit
        'float' => self::TYPE_DOUBLE, // 126 bit
        'timestamp' => self::TYPE_TIMESTAMP,
        'timestamp with time zone' => self::TYPE_TIMESTAMP,
        'timestamp with local time zone' => self::TYPE_TIMESTAMP,
        'date' => self::TYPE_DATE,
        'interval day to second' => self::TYPE_TIME,

        /** Deprecated */
        'long' => self::TYPE_TEXT,
    ];

    public function __construct(protected ConnectionInterface $db, SchemaCache $schemaCache, string $defaultSchema)
    {
        $this->defaultSchema = $defaultSchema;
        parent::__construct($db, $schemaCache);
    }

    public function createColumn(string $type, array|int|string $length = null): ColumnInterface
    {
        return new Column($type, $length);
    }

    protected function resolveTableName(string $name): TableSchemaInterface
    {
        $resolvedName = new TableSchema();

        $parts = array_reverse(
            $this->db->getQuoter()->getTableNameParts($name)
        );

        $resolvedName->name($parts[0] ?? '');
        $resolvedName->schemaName($parts[1] ?? $this->defaultSchema);

        $resolvedName->fullName(
            $resolvedName->getSchemaName() !== $this->defaultSchema ?
            implode('.', array_reverse($parts)) : $resolvedName->getName()
        );

        return $resolvedName;
    }

    /**
     * @link https://docs.oracle.com/cd/B28359_01/server.111/b28337/tdpsg_user_accounts.htm
     *
     * @throws Exception
     * @throws InvalidConfigException
     * @throws NotSupportedException
     * @throws Throwable
     */
    protected function findSchemaNames(): array
    {
        $sql = <<<SQL
        SELECT "u"."USERNAME"
        FROM "DBA_USERS" "u"
        WHERE "u"."DEFAULT_TABLESPACE" NOT IN ('SYSTEM', 'SYSAUX')
        ORDER BY "u"."USERNAME" ASC
        SQL;

        return $this->db->createCommand($sql)->queryColumn();
    }

    /**
     * @throws Exception
     * @throws InvalidConfigException
     * @throws Throwable
     */
    protected function findTableComment(TableSchemaInterface $tableSchema): void
    {
        $sql = <<<SQL
        SELECT "COMMENTS"
        FROM ALL_TAB_COMMENTS
        WHERE
              "OWNER" = :schemaName AND
              "TABLE_NAME" = :tableName
        SQL;

        $comment = $this->db->createCommand($sql, [
            ':schemaName' => $tableSchema->getSchemaName(),
            ':tableName' => $tableSchema->getName(),
        ])->queryScalar();

        $tableSchema->comment(is_string($comment) ? $comment : null);
    }

    /**
     * @throws Exception
     * @throws InvalidConfigException
     * @throws Throwable
     */
    protected function findTableNames(string $schema = ''): array
    {
        if ($schema === '') {
            $sql = <<<SQL
            SELECT TABLE_NAME
            FROM USER_TABLES
            UNION ALL
            SELECT VIEW_NAME AS TABLE_NAME
            FROM USER_VIEWS
            UNION ALL
            SELECT MVIEW_NAME AS TABLE_NAME
            FROM USER_MVIEWS
            ORDER BY TABLE_NAME
            SQL;

            $command = $this->db->createCommand($sql);
        } else {
            $sql = <<<SQL
            SELECT OBJECT_NAME AS TABLE_NAME
            FROM ALL_OBJECTS
            WHERE OBJECT_TYPE IN ('TABLE', 'VIEW', 'MATERIALIZED VIEW') AND OWNER = :schema
            ORDER BY OBJECT_NAME
            SQL;
            $command = $this->db->createCommand($sql, [':schema' => $schema]);
        }

        $rows = $command->queryAll();
        $names = [];

        /** @psalm-var string[][] $rows */
        foreach ($rows as $row) {
            /** @psalm-var string[] $row */
            $row = array_change_key_case($row);
            $names[] = $row['table_name'];
        }

        return $names;
    }

    /**
     * @throws Exception
     * @throws InvalidConfigException
     * @throws Throwable
     */
    protected function loadTableSchema(string $name): TableSchemaInterface|null
    {
        $table = $this->resolveTableName($name);
        $this->findTableComment($table);

        if ($this->findColumns($table)) {
            $this->findConstraints($table);
            return $table;
        }

        return null;
    }

    /**
     * @throws Exception
     * @throws InvalidConfigException
     * @throws NotSupportedException
     * @throws Throwable
     */
    protected function loadTablePrimaryKey(string $tableName): Constraint|null
    {
        /** @psalm-var mixed $tablePrimaryKey */
        $tablePrimaryKey = $this->loadTableConstraints($tableName, self::PRIMARY_KEY);
        return $tablePrimaryKey instanceof Constraint ? $tablePrimaryKey : null;
    }

    /**
     * @throws Exception
     * @throws InvalidConfigException
     * @throws NotSupportedException
     * @throws Throwable
     */
    protected function loadTableForeignKeys(string $tableName): array
    {
        /** @psalm-var mixed $tableForeignKeys */
        $tableForeignKeys = $this->loadTableConstraints($tableName, self::FOREIGN_KEYS);
        return is_array($tableForeignKeys) ? $tableForeignKeys : [];
    }

    /**
     * @throws Exception
     * @throws InvalidConfigException
     * @throws NotSupportedException
     * @throws Throwable
     */
    protected function loadTableIndexes(string $tableName): array
    {
        $sql = <<<SQL
        SELECT "ui"."INDEX_NAME" AS "name", "uicol"."COLUMN_NAME" AS "column_name",
        CASE "ui"."UNIQUENESS" WHEN 'UNIQUE' THEN 1 ELSE 0 END AS "index_is_unique",
        CASE WHEN "uc"."CONSTRAINT_NAME" IS NOT NULL THEN 1 ELSE 0 END AS "index_is_primary"
        FROM "SYS"."USER_INDEXES" "ui"
        LEFT JOIN "SYS"."USER_IND_COLUMNS" "uicol"
        ON "uicol"."INDEX_NAME" = "ui"."INDEX_NAME"
        LEFT JOIN "SYS"."USER_CONSTRAINTS" "uc"
        ON "uc"."OWNER" = "ui"."TABLE_OWNER" AND "uc"."CONSTRAINT_NAME" = "ui"."INDEX_NAME" AND "uc"."CONSTRAINT_TYPE" = 'P'
        WHERE "ui"."TABLE_OWNER" = :schemaName AND "ui"."TABLE_NAME" = :tableName
        ORDER BY "uicol"."COLUMN_POSITION" ASC
        SQL;

        $resolvedName = $this->resolveTableName($tableName);
        $indexes = $this->db->createCommand($sql, [
            ':schemaName' => $resolvedName->getSchemaName(),
            ':tableName' => $resolvedName->getName(),
        ])->queryAll();

        /** @psalm-var array[] $indexes */
        $indexes = array_map('array_change_key_case', $indexes);
        $indexes = DbArrayHelper::index($indexes, null, ['name']);

        $result = [];

        /**
         * @psalm-var object|string|null $name
         * @psalm-var array[] $index
         */
        foreach ($indexes as $name => $index) {
            $columnNames = DbArrayHelper::getColumn($index, 'column_name');

            if ($columnNames[0] === null) {
                $columnNames[0] = '';
            }

            $result[] = (new IndexConstraint())
                ->primary((bool) $index[0]['index_is_primary'])
                ->unique((bool) $index[0]['index_is_unique'])
                ->name($name)
                ->columnNames($columnNames);
        }

        return $result;
    }

    /**
     * @throws Exception
     * @throws InvalidConfigException
     * @throws NotSupportedException
     * @throws Throwable
     */
    protected function loadTableUniques(string $tableName): array
    {
        /** @psalm-var mixed $tableUniques */
        $tableUniques = $this->loadTableConstraints($tableName, self::UNIQUES);
        return is_array($tableUniques) ? $tableUniques : [];
    }

    /**
     * @throws Exception
     * @throws InvalidConfigException
     * @throws NotSupportedException
     * @throws Throwable
     */
    protected function loadTableChecks(string $tableName): array
    {
        /** @psalm-var mixed $tableCheck */
        $tableCheck = $this->loadTableConstraints($tableName, self::CHECKS);
        return is_array($tableCheck) ? $tableCheck : [];
    }

    /**
     * @throws NotSupportedException If this method is called.
     */
    protected function loadTableDefaultValues(string $tableName): array
    {
        throw new NotSupportedException(__METHOD__ . ' is not supported by Oracle.');
    }

    /**
     * Collects the table column metadata.
     *
     * @param TableSchemaInterface $table The table schema.
     *
     * @throws Exception
     * @throws Throwable
     *
     * @return bool Whether the table exists.
     */
    protected function findColumns(TableSchemaInterface $table): bool
    {
        $sql = <<<SQL
        SELECT
            A.COLUMN_NAME,
            A.DATA_TYPE,
            A.DATA_PRECISION,
            A.DATA_SCALE,
            A.IDENTITY_COLUMN,
            (
            CASE A.CHAR_USED WHEN 'C' THEN A.CHAR_LENGTH
                ELSE A.DATA_LENGTH
            END
            ) AS DATA_LENGTH,
            A.NULLABLE,
            A.DATA_DEFAULT,
            (
                SELECT COUNT(*)
                FROM ALL_CONSTRAINTS AC
                INNER JOIN ALL_CONS_COLUMNS ACC ON ACC.CONSTRAINT_NAME=AC.CONSTRAINT_NAME
                WHERE
                     AC.OWNER = A.OWNER
                   AND AC.TABLE_NAME = B.OBJECT_NAME
                   AND ACC.COLUMN_NAME = A.COLUMN_NAME
                   AND AC.CONSTRAINT_TYPE = 'P'
            ) AS IS_PK,
            COM.COMMENTS AS COLUMN_COMMENT
        FROM ALL_TAB_COLUMNS A
            INNER JOIN ALL_OBJECTS B ON B.OWNER = A.OWNER AND LTRIM(B.OBJECT_NAME) = LTRIM(A.TABLE_NAME)
            LEFT JOIN ALL_COL_COMMENTS COM ON (A.OWNER = COM.OWNER AND A.TABLE_NAME = COM.TABLE_NAME AND A.COLUMN_NAME = COM.COLUMN_NAME)
        WHERE
            A.OWNER = :schemaName
            AND B.OBJECT_TYPE IN ('TABLE', 'VIEW', 'MATERIALIZED VIEW')
            AND B.OBJECT_NAME = :tableName
        ORDER BY A.COLUMN_ID
        SQL;

        $columns = $this->db->createCommand($sql, [
            ':tableName' => $table->getName(),
            ':schemaName' => $table->getSchemaName(),
        ])->queryAll();

        if ($columns === []) {
            return false;
        }

        /** @psalm-var string[][] $info */
        foreach ($columns as $info) {
            /** @psalm-var ColumnInfoArray $info */
            $info = array_change_key_case($info);

            $column = $this->loadColumnSchema($info);

            $table->column($info['column_name'], $column);
        }

        return true;
    }

    /**
     * Sequence name of table.
     *
     * @throws Exception
     * @throws InvalidConfigException
     * @throws Throwable
     *
     * @return string|null Whether the sequence exists.
     *
     * @internal TableSchemaInterface `$table->getName()` The table schema.
     */
    protected function getTableSequenceName(string $tableName): string|null
    {
        $sequenceNameSql = <<<SQL
        SELECT
            UD.REFERENCED_NAME AS SEQUENCE_NAME
        FROM USER_DEPENDENCIES UD
            JOIN USER_TRIGGERS UT ON (UT.TRIGGER_NAME = UD.NAME)
        WHERE
            UT.TABLE_NAME = :tableName
            AND UD.TYPE = 'TRIGGER'
            AND UD.REFERENCED_TYPE = 'SEQUENCE'
        SQL;
        $sequenceName = $this->db->createCommand($sequenceNameSql, [':tableName' => $tableName])->queryScalar();

        /** @var string|null */
        return $sequenceName === false ? null : $sequenceName;
    }

    /**
     * Loads the column information into a {@see ColumnSchemaInterface} object.
     *
     * @param array $info The column information.
     *
     * @return ColumnSchemaInterface The column schema object.
     *
     * @psalm-param ColumnInfoArray $info The column information.
     */
    private function loadColumnSchema(array $info): ColumnSchemaInterface
    {
        $dbType = $info['data_type'];
        $type = $this->extractColumnType($dbType, $info);

        $column = $this->createColumnSchema($type);
        $column->name($info['column_name']);
        $column->allowNull($info['nullable'] === 'Y');
        $column->comment($info['column_comment']);
        $column->primaryKey((bool) $info['is_pk']);
        $column->autoIncrement($info['identity_column'] === 'YES');
        $column->size((int) $info['data_length']);
        $column->precision($info['data_precision'] !== null ? (int) $info['data_precision'] : null);
        $column->scale($info['data_scale'] !== null ? (int) $info['data_scale'] : null);
        $column->dbType($dbType);
        $column->defaultValue($this->normalizeDefaultValue($info['data_default'], $column));

        return $column;
    }

    protected function createColumnSchemaFromPhpType(string $phpType, string $type): ColumnSchemaInterface
    {
        if ($phpType === self::PHP_TYPE_RESOURCE) {
            return new BinaryColumnSchema($type, $phpType);
        }

        return parent::createColumnSchemaFromPhpType($phpType, $type);
    }

    /**
     * Converts column's default value according to {@see ColumnSchema::phpType} after retrieval from the database.
     *
     * @param string|null $defaultValue The default value retrieved from the database.
     * @param ColumnSchemaInterface $column The column schema object.
     *
     * @return mixed The normalized default value.
     */
    private function normalizeDefaultValue(string|null $defaultValue, ColumnSchemaInterface $column): mixed
    {
        if ($defaultValue === null || $column->isPrimaryKey()) {
            return null;
        }

        $defaultValue = trim($defaultValue);

        if ($defaultValue === 'NULL') {
            return null;
        }

        if ($column->getType() === self::TYPE_TIMESTAMP && $defaultValue === 'CURRENT_TIMESTAMP') {
            return new Expression($defaultValue);
        }

        if (preg_match("/^'(.*)'$/s", $defaultValue, $matches) === 1) {
            $defaultValue = str_replace("''", "'", $matches[1]);
        }

        return $column->phpTypecast($defaultValue);
    }

    /**
     * Finds constraints and fills them into TableSchemaInterface object passed.
     *
     * @throws Exception
     * @throws InvalidConfigException
     * @throws Throwable
     *
     * @psalm-suppress PossiblyNullArrayOffset
     */
    protected function findConstraints(TableSchemaInterface $table): void
    {
        $sql = <<<SQL
        SELECT
            /*+ PUSH_PRED(C) PUSH_PRED(D) PUSH_PRED(E) */
            D.CONSTRAINT_NAME,
            D.CONSTRAINT_TYPE,
            C.COLUMN_NAME,
            C.POSITION,
            D.R_CONSTRAINT_NAME,
            E.TABLE_NAME AS TABLE_REF,
            F.COLUMN_NAME AS COLUMN_REF,
            C.TABLE_NAME
        FROM ALL_CONS_COLUMNS C
            INNER JOIN ALL_CONSTRAINTS D ON D.OWNER = C.OWNER AND D.CONSTRAINT_NAME = C.CONSTRAINT_NAME
            LEFT JOIN ALL_CONSTRAINTS E ON E.OWNER = D.R_OWNER AND E.CONSTRAINT_NAME = D.R_CONSTRAINT_NAME
            LEFT JOIN ALL_CONS_COLUMNS F ON F.OWNER = E.OWNER AND F.CONSTRAINT_NAME = E.CONSTRAINT_NAME AND F.POSITION = C.POSITION
        WHERE
            C.OWNER = :schemaName
            AND C.TABLE_NAME = :tableName
            ORDER BY D.CONSTRAINT_NAME, C.POSITION
        SQL;

        /**
         * @psalm-var array{
         *   array{
         *     constraint_name: string,
         *     constraint_type: string,
         *     column_name: string,
         *     position: string|null,
         *     r_constraint_name: string|null,
         *     table_ref: string|null,
         *     column_ref: string|null,
         *     table_name: string
         *   }
         * } $rows
         */
        $rows = $this->db->createCommand(
            $sql,
            [':tableName' => $table->getName(), ':schemaName' => $table->getSchemaName()]
        )->queryAll();

        $constraints = [];

        foreach ($rows as $row) {
            /** @psalm-var string[] $row */
            $row = array_change_key_case($row);

            if ($row['constraint_type'] === 'P') {
                $table->getColumns()[$row['column_name']]->primaryKey(true);
                $table->primaryKey($row['column_name']);

                if (empty($table->getSequenceName())) {
                    $table->sequenceName($this->getTableSequenceName($table->getName()));
                }
            }

            if ($row['constraint_type'] !== 'R') {
                /**
                 * This condition isn't checked in `WHERE` because of an Oracle Bug:
                 *
                 * @link https://github.com/yiisoft/yii2/pull/8844
                 */
                continue;
            }

            $name = $row['constraint_name'];

            if (!isset($constraints[$name])) {
                $constraints[$name] = [
                    'tableName' => $row['table_ref'],
                    'columns' => [],
                ];
            }

            $constraints[$name]['columns'][$row['column_name']] = $row['column_ref'];
        }

        foreach ($constraints as $index => $constraint) {
            $table->foreignKey($index, array_merge([$constraint['tableName']], $constraint['columns']));
        }
    }

    /**
     * Returns all unique indexes for the given table.
     *
     * Each array element is of the following structure:.
     *
     * ```php
     * [
     *     'IndexName1' => ['col1' [, ...]],
     *     'IndexName2' => ['col2' [, ...]],
     * ]
     * ```
     *
     * @param TableSchemaInterface $table The table metadata.
     *
     * @throws Exception
     * @throws InvalidConfigException
     * @throws Throwable
     *
     * @return array All unique indexes for the given table.
     */
    public function findUniqueIndexes(TableSchemaInterface $table): array
    {
        $query = <<<SQL
        SELECT
            DIC.INDEX_NAME,
            DIC.COLUMN_NAME
        FROM ALL_INDEXES DI
            INNER JOIN ALL_IND_COLUMNS DIC ON DI.TABLE_NAME = DIC.TABLE_NAME AND DI.INDEX_NAME = DIC.INDEX_NAME
        WHERE
            DI.UNIQUENESS = 'UNIQUE'
            AND DIC.TABLE_OWNER = :schemaName
            AND DIC.TABLE_NAME = :tableName
        ORDER BY DIC.TABLE_NAME, DIC.INDEX_NAME, DIC.COLUMN_POSITION
        SQL;
        $result = [];

        $rows = $this->db->createCommand(
            $query,
            [':tableName' => $table->getName(), ':schemaName' => $table->getschemaName()]
        )->queryAll();

        /** @psalm-var array<array{INDEX_NAME: string, COLUMN_NAME: string}> $rows */
        foreach ($rows as $row) {
            $result[$row['INDEX_NAME']][] = $row['COLUMN_NAME'];
        }

        return $result;
    }

    /**
     * Extracts the data type for the given column.
     *
     * @param string $dbType The database data type
     * @param array $info Column information.
     * @psalm-param ColumnInfoArray $info
     *
     * @return string The abstract column type.
     */
    private function extractColumnType(string $dbType, array $info): string
    {
        $dbType = strtolower($dbType);

        if ($dbType === 'number') {
            $scale = $info['data_scale'] !== null ? (int) $info['data_scale'] : null;

            return match ($scale) {
                null => self::TYPE_DOUBLE,
                0 => self::TYPE_INTEGER,
                default => self::TYPE_DECIMAL,
            };
        }

        $dbType = preg_replace('/\([^)]+\)/', '', $dbType);

        if ($dbType === 'interval day to second' && $info['data_precision'] > 0) {
            return self::TYPE_STRING;
        }

        return self::TYPE_MAP[$dbType] ?? self::TYPE_STRING;
    }

    /**
     * Loads multiple types of constraints and returns the specified ones.
     *
     * @param string $tableName The table name.
     * @param string $returnType The return type:
     * - primaryKey
     * - foreignKeys
     * - uniques
     * - checks
     *
     * @throws Exception
     * @throws InvalidConfigException
     * @throws NotSupportedException
     * @throws Throwable
     *
     * @return mixed Constraints.
     */
    private function loadTableConstraints(string $tableName, string $returnType): mixed
    {
        $sql = <<<SQL
        SELECT
            "uc"."CONSTRAINT_NAME" AS "name",
            "uccol"."COLUMN_NAME" AS "column_name",
            "uc"."CONSTRAINT_TYPE" AS "type",
            "fuc"."OWNER" AS "foreign_table_schema",
            "fuc"."TABLE_NAME" AS "foreign_table_name",
            "fuccol"."COLUMN_NAME" AS "foreign_column_name",
            "uc"."DELETE_RULE" AS "on_delete",
            "uc"."SEARCH_CONDITION" AS "check_expr"
        FROM "USER_CONSTRAINTS" "uc"
        INNER JOIN "USER_CONS_COLUMNS" "uccol"
        ON "uccol"."OWNER" = "uc"."OWNER" AND "uccol"."CONSTRAINT_NAME" = "uc"."CONSTRAINT_NAME"
        LEFT JOIN "USER_CONSTRAINTS" "fuc"
        ON "fuc"."OWNER" = "uc"."R_OWNER" AND "fuc"."CONSTRAINT_NAME" = "uc"."R_CONSTRAINT_NAME"
        LEFT JOIN "USER_CONS_COLUMNS" "fuccol"
        ON "fuccol"."OWNER" = "fuc"."OWNER" AND "fuccol"."CONSTRAINT_NAME" = "fuc"."CONSTRAINT_NAME" AND "fuccol"."POSITION" = "uccol"."POSITION"
        WHERE "uc"."OWNER" = :schemaName AND "uc"."TABLE_NAME" = :tableName
        ORDER BY "uccol"."POSITION" ASC
        SQL;

        $resolvedName = $this->resolveTableName($tableName);
        $constraints = $this->db->createCommand($sql, [
            ':schemaName' => $resolvedName->getSchemaName(),
            ':tableName' => $resolvedName->getName(),
        ])->queryAll();

        /** @psalm-var array[] $constraints */
        $constraints = array_map('array_change_key_case', $constraints);
        $constraints = DbArrayHelper::index($constraints, null, ['type', 'name']);

        $result = [
            self::PRIMARY_KEY => null,
            self::FOREIGN_KEYS => [],
            self::UNIQUES => [],
            self::CHECKS => [],
        ];

        /**
         * @psalm-var string $type
         * @psalm-var array $names
         */
        foreach ($constraints as $type => $names) {
            /**
             * @psalm-var object|string|null $name
             * @psalm-var ConstraintArray $constraint
             */
            foreach ($names as $name => $constraint) {
                switch ($type) {
                    case 'P':
                        $result[self::PRIMARY_KEY] = (new Constraint())
                            ->name($name)
                            ->columnNames(DbArrayHelper::getColumn($constraint, 'column_name'));
                        break;
                    case 'R':
                        $result[self::FOREIGN_KEYS][] = (new ForeignKeyConstraint())
                            ->name($name)
                            ->columnNames(DbArrayHelper::getColumn($constraint, 'column_name'))
                            ->foreignSchemaName($constraint[0]['foreign_table_schema'])
                            ->foreignTableName($constraint[0]['foreign_table_name'])
                            ->foreignColumnNames(DbArrayHelper::getColumn($constraint, 'foreign_column_name'))
                            ->onDelete($constraint[0]['on_delete'])
                            ->onUpdate(null);
                        break;
                    case 'U':
                        $result[self::UNIQUES][] = (new Constraint())
                            ->name($name)
                            ->columnNames(DbArrayHelper::getColumn($constraint, 'column_name'));
                        break;
                    case 'C':
                        $result[self::CHECKS][] = (new CheckConstraint())
                            ->name($name)
                            ->columnNames(DbArrayHelper::getColumn($constraint, 'column_name'))
                            ->expression($constraint[0]['check_expr']);
                        break;
                }
            }
        }

        foreach ($result as $type => $data) {
            $this->setTableMetadata($tableName, $type, $data);
        }

        return $result[$returnType];
    }

    /**
     * @throws Exception
     * @throws InvalidConfigException
     * @throws Throwable
     */
    protected function findViewNames(string $schema = ''): array
    {
        $sql = match ($schema) {
            '' => <<<SQL
            SELECT VIEW_NAME FROM USER_VIEWS
            SQL,
            default => <<<SQL
            SELECT VIEW_NAME FROM ALL_VIEWS WHERE OWNER = '$schema'
            SQL,
        };

        /** @psalm-var string[][] $views */
        $views = $this->db->createCommand($sql)->queryAll();

        foreach ($views as $key => $view) {
            $views[$key] = $view['VIEW_NAME'];
        }

        return $views;
    }

    /**
     * Returns the cache key for the specified table name.
     *
     * @param string $name The table name.
     *
     * @return array The cache key.
     *
     * @psalm-suppress DeprecatedMethod
     */
    protected function getCacheKey(string $name): array
    {
        return array_merge([self::class], $this->generateCacheKey(), [$this->db->getQuoter()->getRawTableName($name)]);
    }

    /**
     * Returns the cache tag name.
     *
     * This allows {@see refresh()} to invalidate all cached table schemas.
     *
     * @return string The cache tag name.
     */
    protected function getCacheTag(): string
    {
        return md5(serialize(array_merge([self::class], $this->generateCacheKey())));
    }
}