MySQL插入到带有另一个表的外键ID的表中

Question

I have two tables: p_model: (id auto inc), (name), (p_category_id) AND p_category: (id), (name)

Basically every model is associated by a category. I need to generate a INSERT statement that inserts a new model and adds the id of the p_category associated to it.

My PHP Function Passes both values:

function Perform_Insert_Model($model_name, $category_name)
{
$statement = "INSERT INTO p_model(`name`,`p_category_id`) VALUES ('$model_name','??????')";

//Where the "??????" is I need a statement that searches for $category_name (string) in the p_category table and returns the id.

....
}

An example call to the function would be $database->Perform_Insert_Model("Banana","Fruit"). Banana would then be a new product model and have a foreign key association of fruit's ID.

Answer 1

You can try this kind of query (this is just 1 query):

INSERT INTO p_model(`name`,`p_category_id`) SELECT '$model_name', `p_category_id`
   FROM p_category WHERE `category_name`='$category_name';

Note: this assumes there is only 1 category by the given category_name or it will insert multiple records in p_model