使用多个条件从 tarantool 中选择 [英] Select from tarantool using multiple conditions

问题描述

如何一次选择一个空间中的两个或多个字段的条件?我在文档中没有找到示例.

How do i make a select with conditions with two or more fields from one space at once? I didn't find an example in the documentation.

推荐答案

有两种方法可以做到这一点:使用 SQL 或使用较低级别的 lua API.

There are 2 ways to do this: using SQL or using a lower-level lua API.

第一个需要你设置空间格式(见此处).它看起来像这样:

The first one requires you to set space format (see here). It looks like this:

box.space.myusers:format({{name='id',type='number'},
                          {name='first_name',type='string'},
                          {name='last_name',type='string'}})

这是 SQL 找出列名所必需的.然后就可以查询如下:

This is required for SQL to figure out column names. Then you can query it as follows:

box.execute([[SELECT "id" FROM "myusers" WHERE "first_name"='John' AND "last_name"='Doe';]])

另一种选择相同空间的方法是:

Another way to select from the same space is:

user_ids = {}
for_,user in box.space.myusers.index.first_name:pairs("John") do
    if user.last_name == "Doe" then
        table.insert(user_ids, user.id)
    end
end

查看此处了解有关低水平空间 API.

Look here for more details on the low-level space API.

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