与select单条记录唯一的区别即，into()的参数是一个vector。其实用多个vector这种方式并不是一个很好的选择，后面会介绍基于数据结构的方式。
3.简单的insert
| TEST(soci,insert_exist) { try { session sql(mysql, "db=soci user=dantezhu"); string name = "dandan"; int sex = 1; sql << "insert into tb_test(name, sex) values(:name, :sex)", use(name), use(sex); } catch (exception const &e) { SUCCEED()<<e.what(); } } TEST(soci,insert_exist) { try { session sql(mysql, "db=soci user=dantezhu"); string name = "dandan"; int sex = 1; sql << "insert into tb_test(name, sex) values(:name, :sex)", use(name), use(sex); } catch (exception const &e) { SUCCEED()<<e.what(); } } |
insert，update，delete都有两个同样的问题:
a)affect_rows(操作的行数)没有办法返回
b)操作的id无法知道，尤其对于insert的主键是自增的情况下，无法知道插入的主键的值是多少。
update和delete都与insert相似，这里就不再多说。
接下来是这个框架的很重要的一个特性，即数据库表与数据结构绑定：
首先我们需要定义一个结构体，并告知soci怎么让列名和数据结构的字段对应起来:
| struct Person { int id; std::string name; int sex; }; namespace soci { template<> struct type_conversion<Person> { typedef values base_type; static void from_base(values const & v, indicator /* ind */, Person & p) { p.id = v.get<int>("id"); p.name = v.get<std::string>("name"); p.sex = v.get<int>("sex"); } static void to_base(const Person & p, values & v, indicator & ind) { v.set("id", p.id); v.set("name", p.name); v.set("sex", p.sex); ind = i_ok; } }; } struct Person { int id; std::string name; int sex; }; namespace soci { template<> struct type_conversion<Person> { typedef values base_type; static void from_base(values const & v, indicator /* ind */, Person & p) { p.id = v.get<int>("id"); p.name = v.get<std::string>("name"); p.sex = v.get<int>("sex"); } static void to_base(const Person & p, values & v, indicator & ind) { v.set("id", p.id); v.set("name", p.name); v.set("sex", p.sex); ind = i_ok; } }; } |
关于
| template<> struct type_conversion<Person> template<> struct type_conversion<Person> |
这里，官方的文档是是有误的，我查了好长时间，按照上面的写法来写即可。
1.用数据结构来select
| TEST(soci,select_obj_one) { try { session sql(mysql, "db=soci user=dantezhu"); indicator ind; int count; sql << "select count(*) from tb_test", into(count, ind); ASSERT_EQ(ind, i_ok) << count; string name = "dandan"; Person p; sql << "select id,name,sex from tb_test where name = :name", into(p, ind), use(name); ASSERT_EQ(ind, i_ok) << name; if (sql.got_data()) { cout<< p.id << "," << p.name << "," << p.sex << endl; } } catch (exception const &e) { FAIL()<<e.what(); } } TEST(soci,select_obj_one) { try { session sql(mysql, "db=soci user=dantezhu"); indicator ind; int count; sql << "select count(*) from tb_test", into(count, ind); ASSERT_EQ(ind, i_ok) << count; string name = "dandan"; Person p; sql << "select id,name,sex from tb_test where name = :name", into(p, ind), use(name); ASSERT_EQ(ind, i_ok) << name; if (sql.got_data()) { cout<< p.id << "," << p.name << "," << p.sex << endl; } } catch (exception const &e) { FAIL()<<e.what(); } } |
