thinkphp query returns a simple field array method _php instance

This paper describes the method of thinkphp query return simple field array, which is a very useful function in thinkphp program design. Here's how:

Typically, a SELECT statement is used. Returns an array of fields that are more complex in structure. The following is a simple query:

$map [' parentid '] = $id; $sub _ids = D (' Category ')->where ($map)->field ("CatID")->select ();

After the query, the result is:

[{"CatID": "},{", "catid": "},{", "catid": "" "},{" catid ":" "},{" catid ":"},{"catid": "},{" CATID ":" 29 "},{" CatID ":" 30 "}]

From the structure it is seen that this is a complex array of structures whose elements are a map.
If we just need a simple array that contains only the elements of a number field, you can use the following methods:

$sub _ids = D (' Category ')->where ($map)->getfield (' catid ', true);

After the query, the result is:

["23", "24", "25", "26", "27", "28", "29", "30"]

The results of the query are immediately clear and bright!

I hope that the method described in this article will be helpful to the thinkphp of our students.

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