如何使用php从另一个表中获取一个表字段值

You can use simply GROUP_CONCAT() together with FIND_IN_SET() for that:

SELECT
    cd.cf_did AS id,
    cd.cf_firstname AS name,
    GROUP_CONCAT(ct.cf_ctname SEPARATOR ', ') AS cranetype
FROM
    cranedetails cd,
    cranetype ct
WHERE
    FIND_IN_SET(ct.cf_ctid, cd.cf_cranetype)
GROUP BY
    cd.cf_did,
    cd.cf_firstname

Output is:

+----+----------+---------------------------------------------------------------------------------------+
| id | name     | cranetype                                                                             |
+----+----------+---------------------------------------------------------------------------------------+
|  1 | Alexy    | ROUGH TERRAIN CRANES, ALL TERRAIN CRANES                                              |
|  2 | Thomas   | ARICULATING BOOM CRANES, ELEVATORS, ALL TERRAIN CRANES                                |
|  3 | Thomas   | ALL TERRAIN CRANES, YARD CRANES, ARICULATING BOOM CRANES, ELEVATORS                   |
|  4 | Thomasxc | CRAWLER CRANES, ARICULATING BOOM CRANES, TRUCK CRANES: TELESCOPIC BOOM, MOBILE CRANES |
|  5 | Thomaseg | ALL TERRAIN CRANES, ELEVATORS, ELEVATOR – HYDRAULIC                                   |
+----+----------+---------------------------------------------------------------------------------------+
5 rows in set

If you want to group the result only by name (because there are duplicated names), just remove cd.cf_did from the query and add DISTINCT to filter duplicated cranetype values, i.e:

SELECT
    cd.cf_firstname AS name,
    GROUP_CONCAT(DISTINCT ct.cf_ctname SEPARATOR ', ') AS cranetype
FROM
    cranedetails cd,
    cranetype ct
WHERE
    FIND_IN_SET(ct.cf_ctid, cd.cf_cranetype)
GROUP BY
    cd.cf_firstname

Result will be:

+----------+---------------------------------------------------------------------------------------+
| name     | cranetype                                                                             |
+----------+---------------------------------------------------------------------------------------+
| Alexy    | ROUGH TERRAIN CRANES, ALL TERRAIN CRANES                                              |
| Thomas   | ELEVATORS, ALL TERRAIN CRANES, YARD CRANES, ARICULATING BOOM CRANES                   |
| Thomaseg | ELEVATORS, ELEVATOR – HYDRAULIC, ALL TERRAIN CRANES                                   |
| Thomasxc | TRUCK CRANES: TELESCOPIC BOOM, MOBILE CRANES, CRAWLER CRANES, ARICULATING BOOM CRANES |
+----------+---------------------------------------------------------------------------------------+
4 rows in set

Use sub queries to fetch this for reference http://dev.mysql.com/doc/refman/5.7/en/subqueries.html

For me, it looks like you are storing a string value (or VARCHAR) of integer values (your cranetype ids) joined by comma.

If so, I would consider redesigning your database to have a table e.g.

• cranenames with cf_nid, cf_firstname
• cranetypes with cf_ctid cf_ctname
• cranedetails with cf_did, cf_nid, cf_ctid

In the cranedetails, make an entry for every cranetype associated with a cranename. The cf_nid and cf_ctid shoul be, of course, foreign key relations to the respective tables.

With your current design, you would have to explode the string value of your cf_cranetype to get an array of integers (or strings, looking like integers), and your second query had to look like this: "SELECT * FROM cf_cranetype WHERE cf_ctid IN '" . join($YOUR_ARRAY, ',') . "'"