inner join to 3 tables but dont show anything - mysql

Question

there are 3 tables like this:
mysql> describe detoc;
+-----------+--------------+------+-----+------------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-----------+--------------+------+-----+------------+----------------+
| registro | int(12) | NO | PRI | NULL | auto_increment |
| ordcomp | int(12) | NO | MUL | 0 | |
| requis | int(12) | YES | MUL | 0 | |
| requisnum | int(12) | YES | | 0 | |
| material | char(6) | YES | MUL | | |
| cantidad | double(18,7) | YES | | 0.0000000 | |
| unidad | char(7) | YES | | | |
| presest | double(18,7) | YES | | 0.0000000 | |
| unidadpre | char(7) | YES | | | |
| surtido | double(18,7) | YES | | 0.0000000 | |
| cerrada | tinyint(1) | YES | | 0 | |
| costo | double(18,7) | YES | | 0.0000000 | |
| impuesto | double(18,7) | YES | | 0.0000000 | |
| fechalta | date | YES | | 0000-00-00 | |
| usuarmod | char(6) | YES | | | |
| fechamod | date | YES | | 0000-00-00 | |
+-----------+--------------+------+-----+------------+----------------+
16 rows in set (0.02 sec)
mysql> describe ordenescompra;
+------------+------------+------+-----+------------+----------------+
| Field | Type | Null | Key | Default | Extra |
+------------+------------+------+-----+------------+----------------+
| registro | int(12) | NO | PRI | NULL | auto_increment |
| clave | int(12) | NO | MUL | 0 | |
| area | char(6) | NO | MUL | | |
| usuariocre | char(6) | NO | MUL | | |
| cveprov | char(6) | YES | | | |
| fechacomp | char(10) | YES | | | |
| emailconf | tinyint(1) | YES | | 0 | |
| confprov | tinyint(1) | YES | | 0 | |
| cerrada | tinyint(1) | YES | | 0 | |
| fechalta | date | YES | | 0000-00-00 | |
| usuarmod | char(6) | YES | | | |
| fechamod | date | YES | | 0000-00-00 | |
+------------+------------+------+-----+------------+----------------+
12 rows in set (0.02 sec)
mysql> describe materiales;
+-----------+--------------+------+-----+------------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-----------+--------------+------+-----+------------+----------------+
| registro | int(12) | NO | PRI | NULL | auto_increment |
| clave | char(6) | NO | UNI | | |
| clave2 | char(20) | YES | MUL | | |
| descr | char(30) | YES | | | |
| descr2 | char(250) | YES | | | |
| unidad | char(7) | YES | | | |
| presest | double(18,7) | YES | | 0.0000000 | |
| unidadpre | char(7) | YES | | | |
| codbar | char(30) | YES | | | |
| impuesto | double(18,7) | YES | | 0.0000000 | |
| mantpend | tinyint(1) | YES | | 0 | |
| grupplat | char(6) | YES | MUL | | |
| fechalta | date | YES | | 0000-00-00 | |
| usuarmod | char(6) | YES | | | |
| fechamod | date | YES | | 0000-00-00 | |
+-----------+--------------+------+-----+------------+----------------+
I need to display data , but returns nothing, the syntaxis is:
SELECT * FROM DETOC INNER JOIN MATERIALES
ON DETOC.MATERIAL = MATERIALES.CLAVE
INNER JOIN ORDENESCOMPRA
ON DETOC.ORDCOMP = ORDENESCOMPRA.CLAVE
WHERE MATERIALES.CLAVE>=' '
AND MATERIALES.CLAVE<='ZZZZZZ'
AND MATERIALES.GRUPPLAT>=' '
AND MATERIALES.GRUPPLAT<='ZZZZZZ'
AND ORDENESCOMPRA.CLAVE>=' '
AND ORDENESCOMPRA.CLAVE<='999999999999'
ORDER BY ;
and i try this syntaxis too, but i have a error to show, because they're different number of columns...
(SELECT * FROM DETOC
INNER JOIN ORDENESCOMPRA
ON DETOC.ORDCOMP = ORDENESCOMPRA.CLAVE
WHERE ORDENESCOMPRA.CLAVE>="8780"
AND ORDENESCOMPRA.CLAVE<="8790"
ORDER BY CLAVE)
UNION
(SELECT * FROM DETOC
INNER JOIN MATERIALES
ON DETOC.MATERIAL = MATERIALES.CLAVE
WHERE MATERIALES.CLAVE>=""
AND MATERIALES.CLAVE<=""
AND MATERIALES.GRUPPLAT>=" "
AND MATERIALES.GRUPPLAT<=" ")
Can anybody help me ???

Answer 1

Please try using UPPER function while comparing MATERIALES.CLAVE and MATERIALES.GRUPPLAT with their upper bounds, like in the following query:
SELECT
*
FROM
DETOC
INNER JOIN MATERIALES
ON DETOC.MATERIAL = MATERIALES.CLAVE
INNER JOIN ORDENESCOMPRA
ON DETOC.ORDCOMP = ORDENESCOMPRA.CLAVE
WHERE
MATERIALES.CLAVE >= ' '
AND UPPER(MATERIALES.CLAVE) <= 'ZZZZZZ'
AND MATERIALES.GRUPPLAT >= ' '
AND UPPER(MATERIALES.GRUPPLAT) <= 'ZZZZZZ'
AND ORDENESCOMPRA.CLAVE >= ' '
AND ORDENESCOMPRA.CLAVE <= '999999999999';
I'm not sure whether this will solve your problem, but I'm certain that when in MATERIALES.CLAVE there would be i.e. value AABBcc the query would exclude the record from the result set.
Hope it helps some way.