c++ SQLite 特别好用的库使用实例-查询（2）

void _QueryDB()
{
    Kompex::SQLiteDatabase *pDatabase = new Kompex::SQLiteDatabase("test.db", SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
    Kompex::SQLiteStatement *pStmt = new Kompex::SQLiteStatement(pDatabase);

    {
        double d1 = pStmt->SqlAggregateFuncResult("SELECT COUNT(*) FROM user WHERE lastName = 'Lehmann';");
        double d2 = pStmt->SqlAggregateFuncResult("SELECT COUNT(weight) FROM user;");
        double d3 = pStmt->SqlAggregateFuncResult("SELECT MAX(age) FROM user;");
        double d4 = pStmt->SqlAggregateFuncResult("SELECT MIN(age) FROM user;");
        double d5 = pStmt->SqlAggregateFuncResult("SELECT AVG(age) FROM user;");
        double d6 = pStmt->SqlAggregateFuncResult("SELECT SUM(age) FROM user;");
        double d7 = pStmt->SqlAggregateFuncResult("SELECT TOTAL(age) FROM user;");
    }
    
    {
        pStmt->Sql("SELECT firstName FROM user WHERE lastName = 'Lehmann';");
        const char* strName = pStmt->GetColumnName(0);
        int nCount = pStmt->GetColumnCount();
        const char* strDataBaseName = pStmt->GetColumnDatabaseName(0);
        const char* strTableName = pStmt->GetColumnTableName(0);
        const char* strOriginName = pStmt->GetColumnOriginName(0);
        pStmt->FreeQuery();
    }

    {
        pStmt->Sql("SELECT * FROM user");
        while (pStmt->FetchRow())
        {
            double db1 = pStmt->GetColumnDouble(0);
            std::string str1 = pStmt->GetColumnString(1);
            std::string str2 = pStmt->GetColumnString(2);
            std::string str3 = pStmt->GetColumnString(3);
            std::string str4 = pStmt->GetColumnString(4);
            int Type1 = pStmt->GetColumnType(0);
            int Type2 = pStmt->GetColumnType(1);
            int Type3 = pStmt->GetColumnType(2);
            int Type4 = pStmt->GetColumnType(3);
            int Type5 = pStmt->GetColumnType(4);
        }
        pStmt->FreeQuery();
    }

    {
        //获取数据表的列数 列名
        pStmt->Sql("SELECT * FROM user");
        int nCount = pStmt->GetColumnCount();
        for (int i = 0; i < nCount;i++)
        {
            const char* strName = pStmt->GetColumnName(i);
        }
        pStmt->FreeQuery();
    }

    {
        //获取所有的表
        pStmt->Sql("SELECT name FROM sqlite_master WHERE type = 'table' ORDER BY name");
        while (pStmt->FetchRow())
        {
            std::string str1 = pStmt->GetColumnString(0);
            int yyyy = 66;
        }

        pStmt->FreeQuery();
    }
    pDatabase->Close();
}