File indexing completed on 2025-01-05 04:46:58

 /*
     SPDX-FileCopyrightText: 2006 Tobias Koenig <tokoe@kde.org>
     SPDX-FileCopyrightText: 2012 Volker Krause <vkrause@kde.org>
 
     SPDX-License-Identifier: LGPL-2.0-or-later
 */
 #pragma once
 
 #include <QHash>
 #include <QSharedPointer>
 #include <QSqlDatabase>
 #include <QStringList>
 
 class DbIntrospectorTest;
 
 namespace Akonadi
 {
 namespace Server
 {
 /**
  * Methods for introspecting the current state of a database schema.
  * I.e. this is about the structure of a database, not its content.
  */
 class DbIntrospector
 {
 public:
     using Ptr = QSharedPointer<DbIntrospector>;
 
     /** A structure describing an existing foreign key. */
     class ForeignKey
     {
     public:
         QString name;
         QString column;
         QString refTable;
         QString refColumn;
         QString onUpdate; // TODO use same enum as DbInitializer
         QString onDelete; // dito
     };
 
     /**
      * Returns an introspector instance for a given database.
      */
     static DbIntrospector::Ptr createInstance(const QSqlDatabase &database);
 
     virtual ~DbIntrospector();
 
     /**
      * Returns @c true if table @p tableName exists.
      * The default implementation relies on QSqlDatabase::tables(). Usually this
      * does not need to be reimplemented.
      */
     virtual bool hasTable(const QString &tableName);
 
     /**
      * Returns @c true of the given table has an index with the given name.
      * The default implementation performs the query returned by hasIndexQuery().
      * @see hasIndexQuery()
      * @throws DbException on database errors.
      */
     virtual bool hasIndex(const QString &tableName, const QString &indexName);
 
     /**
      * Check whether table @p tableName has a column named @p columnName.
      * The default implementation should work with all backends.
      */
     virtual bool hasColumn(const QString &tableName, const QString &columnName);
 
     /**
      * Check whether table @p tableName is empty, ie. does not contain any rows.
      * The default implementation should work for all backends.
      * @throws DbException on database errors.
      */
     virtual bool isTableEmpty(const QString &tableName);
 
     /**
      * Returns the foreign key constraints on table @p tableName.
      * The default implementation returns an empty list, so any backend supporting
      * referential integrity should reimplement this.
      */
     virtual QList<ForeignKey> foreignKeyConstraints(const QString &tableName);
 
     /**
      * Returns query to retrieve the next autoincrement value for @p tableName.@p columnName.
      */
     virtual QString getAutoIncrementValueQuery(const QString &tableName, const QString &columnName) = 0;
 
     /**
      * Returns query to update the next autoincrement value for @p tableName.@p columnName to value @p value.
      */
     virtual QString updateAutoIncrementValueQuery(const QString &tableName, const QString &columnName, qint64 value) = 0;
 
 protected:
     /**
      * Creates a new database introspector, call from subclass.
      *
      * @param database The database to introspect.
      */
     DbIntrospector(const QSqlDatabase &database);
 
     /**
      * Returns a query string to determine if @p tableName has an index @p indexName.
      * The query is expected to have one boolean result row/column.
      * This is used by the default implementation of hasIndex() only, thus reimplementation
      * is not necessary if you reimplement hasIndex()
      * The default implementation asserts.
      */
     virtual QString hasIndexQuery(const QString &tableName, const QString &indexName);
 
     /** The database connection we are introspecting. */
     QSqlDatabase m_database;
 
 private:
     Q_DISABLE_COPY_MOVE(DbIntrospector)
 
     friend class ::DbIntrospectorTest;
     QHash<QString, QStringList> m_columnCache; // avoids extra db roundtrips
 };
 
 } // namespace Server
 } // namespace Akonadi