यदि आप सभी पंक्तियों (थोक आउटपुट) चाहते हैं और एक समय में एक पंक्ति नहीं चाहते हैं, तो नीचे तेज होना चाहिए और सभी पंक्तियों के आउटपुट में सभी कॉलम होंगे।
आइए नीचे दी गई तालिका के क्षेत्रों पर विचार करें।obj_mobiles - आईडी | एम1 | M2obj_tablets - आईडी | टी1 | T2obj_कंप्यूटर - आईडी | सी1 | C2ऑब्जेक्ट्स - आईडी | टाइप | नाम | आदि,
Select objects.*, typestable.*
from (
select ID as oID, "mobile" as otype, M1, M2, NULL T1, NULL T2, NULL C1, NULL C2 from obj_mobiles
union all
select ID as oID, "tablet" as otype, NULL, NULL, T1, T2, NULL, NULL from obj_tablets
union all
select ID as oID, "computer" as otype, NULL, NULL, NULL, NULL, C1, C2 from obj_computers) as typestable
left join objects on typestable.oID = objects.ID and typestable.otype = objects.type;
+------+--------------------+----------+------+----------+------+------+------+------+------+------+
| ID | name | type | ID | type | M1 | M2 | T1 | T2 | C1 | C2 |
+------+--------------------+----------+------+----------+------+------+------+------+------+------+
| 1 | Samsung Galaxy s2 | mobile | 1 | mobile | 1 | Thin | NULL | NULL | NULL | NULL |
| 2 | Samsung Galaxy Tab | tablet | 2 | tablet | NULL | NULL | 0.98 | 10 | NULL | NULL |
| 3 | Dell Inspiron | computer | 3 | computer | NULL | NULL | NULL | NULL | 4.98 | 1000 |
+------+--------------------+----------+------+----------+------+------+------+------+------+------+
तालिका नीचे के रूप में बनाई गई है।
mysql> create table objects (ID int, name varchar(50), type varchar (15));
Query OK, 0 rows affected (0.05 sec)
mysql> insert into objects values (1, "Samsung Galaxy s2", "mobile"), (2, "Samsung Galaxy Tab", "tablet"), (3, "Dell Inspiron", "computer");
Query OK, 3 rows affected (0.00 sec)
Records: 3 Duplicates: 0 Warnings: 0
mysql> create table obj_mobiles (ID int, M1 int, M2 varchar(10));
Query OK, 0 rows affected (0.03 sec)
mysql> insert into obj_mobiles values (1, 0.98, "Thin");
Query OK, 1 row affected (0.00 sec)
mysql> create table obj_tablets (ID int, T1 float, T2 int(10));
Query OK, 0 rows affected (0.03 sec)
mysql> insert into obj_tablets values (2, 0.98, 10);
Query OK, 1 row affected (0.00 sec)
mysql> create table obj_computers (ID int, C1 float, C2 int(10));
Query OK, 0 rows affected (0.03 sec)
insert into obj_computers values (3, 4.98, 1000);
यह भी पुष्टि करने के लिए कि कॉलम के डेटाटाइप मूल कॉलम के समान हैं, परिणाम एक टेबल में सहेजा जाता है और डेटाटाइप नीचे चेक किए जाते हैं।
create table temp_result as
Select objects.*, typestable.*
from (
select ID as oID, "mobile" as otype, M1, M2, NULL T1, NULL T2, NULL C1, NULL C2 from obj_mobiles
union all
select ID as oID, "tablet" as otype, NULL, NULL, T1, T2, NULL, NULL from obj_tablets
union all
select ID as oID, "computer" as otype, NULL, NULL, NULL, NULL, C1, C2 from obj_computers) as typestable
left join objects on typestable.oID = objects.ID and typestable.otype = objects.type;
mysql> desc temp_result;
+-------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+-------+
| ID | int(11) | YES | | NULL | |
| name | varchar(50) | YES | | NULL | |
| type | varchar(15) | YES | | NULL | |
| oID | int(11) | YES | | NULL | |
| otype | varchar(8) | NO | | | |
| M1 | int(11) | YES | | NULL | |
| M2 | varchar(10) | YES | | NULL | |
| T1 | float | YES | | NULL | |
| T2 | int(11) | YES | | NULL | |
| C1 | float | YES | | NULL | |
| C2 | int(11) | YES | | NULL | |
+-------+-------------+------+-----+---------+-------+
11 rows in set (0.00 sec)
