SQL 编程

This overview assumes that you have at least a basic knowledge of SQL. You should be able to understand simple SELECT , INSERT , UPDATE ，和 DELETE statements. Although the QSqlTableModel class provides an interface to database browsing and editing that does not require a knowledge of SQL, a basic understanding of SQL is highly recommended. A standard text covering SQL databases is An Introduction to Database Systems (7th Ed.) by C. J. Date, ISBN 0201385902.

话题：

数据库类

这些类提供对 SQL 数据库的访问。

QSql	Contains miscellaneous identifiers used throughout the Qt SQL module
QSqlDatabase	处理数据库连接
QSqlDriver	Abstract base class for accessing specific SQL databases
QSqlDriverCreator	Template class that provides a SQL driver factory for a specific driver type
QSqlDriverCreatorBase	The base class for SQL driver factories
QSqlError	SQL 数据库错误信息
QSqlField	操纵 SQL 数据库表和视图中的字段
QSqlIndex	Functions to manipulate and describe database indexes
QSqlQuery	执行和操纵 SQL 语句的手段
QSqlQueryModel	Read-only data model for SQL result sets
QSqlRecord	封装数据库记录
QSqlRelationalTableModel	Editable data model for a single database table, with foreign key support
QSqlResult	Abstract interface for accessing data from specific SQL databases
QSqlTableModel	Editable data model for a single database table

SQL 类分为 3 层：

驱动层

This comprises the classes QSqlDriver , QSqlDriverCreator , QSqlDriverCreatorBase , QSqlDriverPlugin ，和 QSqlResult .

This layer provides the low-level bridge between the specific databases and the SQL API layer. See SQL 数据库驱动程序了解更多信息。

SQL API 层

These classes provide access to databases. Connections are made using the QSqlDatabase class. Database interaction is achieved by using the QSqlQuery class. In addition to QSqlDatabase and QSqlQuery , the SQL API layer is supported by QSqlError , QSqlField , QSqlIndex ，和 QSqlRecord .

用户界面层

These classes link the data from a database to data-aware widgets. They include QSqlQueryModel , QSqlTableModel ，和 QSqlRelationalTableModel . These classes are designed to work with Qt's 模型/视图框架 .

注意， QCoreApplication object must be instantiated before using any of these classes.