c++ SQL查询构建库

Question

我正在寻找一个提供与 c# SelectQueryBuilder 库类似功能的 c++ 库

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

即它允许人们摆脱构建可怕的串联字符串以形成动态 SQL 查询，而是拥有一个库，该库提供一个接口，您可以通过它传递表、要从表中选择的元素等，然后它以字符串形式返回 SQL 查询。

非常感谢任何帮助

编辑：我正在构建的示例查询....直到运行时我们才会知道要选择的实际列，例如不知道会有多少个 VAR1...VARx 以及它们到底是什么。

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