Question

我正在寻找一个c ++库，它提供与c＃SelectQueryBuilder库类似的功能

http://www.codeproject.com/Articles/13419/SelectQueryBuilder-Building-complex-and-flexible-S

即。它允许一个人摆脱构建可怕的连接字符串以形成动态SQL查询，而是拥有一个提供接口的库，通过它传递表，要从表中选择的元素等，以及它以字符串形式返回SQL查询。

任何帮助非常感谢

编辑：我正在构建的示例查询....我们不知道选择的实际列，直到运行时，例如不知道会有多少VAR1 ... VARx以及它们究竟是什么。

SELECT * FROM 
    (
        SELECT 
            table_1.id, 
            table_2.name, 
            (select(COALESCE(sum(table_1.col_1 * 1.0) / NULLIF(sum(table_1.col_2 - table_1.col_3),0) * 100,0))) as VAR1, 
            (select(COALESCE(sum(table_1.col_4 * 1.0) / NULLIF(sum(table_1.col_5),0) * 100,0))) as VAR2, 
            sum(table_1.col_2) as VAR3 
        FROM table_1, table_2 
        WHERE table_1.id = table_2.id 
        GROUP BY table_1.id, table_2.name 
    ) VARIABLES 
WHERE VAR3 > 1000

Answer 1

使用QSqlQuery，您可以使用占位符并将值绑定到它们：

QSqlQuery query;
query.prepare("INSERT INTO person (id, forename, surname) "
              "VALUES (:id, :forename, :surname)");
query.bindValue(":id", 1001);
query.bindValue(":forename", "Bart");
query.bindValue(":surname", "Simpson");
query.exec();

或

QSqlQuery query;
query.prepare("INSERT INTO person (id, forename, surname) "
              "VALUES (?, ?, ?)");
query.addBindValue(1001);
query.addBindValue("Bart");
query.addBindValue("Simpson");
query.exec();

http://qt-project.org/doc/qt-5.0/qtsql/qsqlquery.html#approaches-to-binding-values

c ++ SQL查询构建库

1 个答案: