Jumat, Januari 10, 2014
coretan asti
Menambah Kolom pada Tabel
Kita juga bisa mengatur
letak kolom yang akan kita buat
Modifikasi Nama Tabel
Modifikasi Definisi Tabel
Mengganti Nama Kolom
Menghapus Kolom
Menghapus & Menambah Primary Key
Dalam menambah kolom
dalam tabel kita bisa menggunakan perintah alter table, contohnya kita akan
menambahkan kolom pada tabel t_mobil :
mysql> alter table
t_mobil add
harga bigint(11);
Query OK, 2 rows affected
(0.16 sec)
Records: 2 Duplicates: 0
Warnings: 0
mysql> desc t_mobil;
+----------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+----------+-------------+------+-----+---------+-------+
| id_mobil |
varchar(8) | NO | PRI | NULL |
|
| type | varchar(20) | YES | |
NULL | |
| harga | bigint(11) | YES
| | NULL |
|
+----------+-------------+------+-----+---------+-------+
3 rows in set (0.01 sec)
mysql> alter table
t_mobil add
series varchar(8) after type;
Query OK, 2 rows affected
(0.12 sec)
Records: 2 Duplicates: 0
Warnings: 0
mysql> desc t_mobil;
+----------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+----------+-------------+------+-----+---------+-------+
| id_mobil |
varchar(8) | NO | PRI | NULL |
|
| type | varchar(20) | YES | |
NULL | |
| series | varchar(8)
| YES | | NULL
| |
| harga | bigint(11) | YES
| | NULL |
|
+----------+-------------+------+-----+---------+-------+
4 rows in set (0.01 sec)Modifikasi Nama Tabel
Dalam memodifikasi
definisi tabel contohnya jika kita ingin mengganti definisi dari t_mobil maka
caranya :
mysql> alter table
t_mobil rename
to t_car;
Query OK, 0 rows affected
(0.07 sec)
mysql> desc t_car;
+----------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+----------+-------------+------+-----+---------+-------+
| id_mobil |
varchar(8) | NO | PRI | NULL |
|
| type | varchar(20) | YES | |
NULL | |
| series | varchar(8) | YES | |
NULL | |
| harga | bigint(11) | YES
| | NULL |
|
+----------+-------------+------+-----+---------+-------+
4 rows in set (0.04 sec)Modifikasi Definisi Tabel
Dalam memodifikasi
definisi tabel contohnya jika kita ingin mengganti definisi dari t_car maka
caranya :
mysql> alter table
t_car modify
type varchar(15), modify series varchar(10);
Query OK, 2 rows affected
(0.14 sec)
Records: 2 Duplicates: 0
Warnings: 0
mysql> desc t_car;
+----------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+----------+-------------+------+-----+---------+-------+
| id_mobil |
varchar(8) | NO | PRI | NULL |
|
| type | varchar(15) | YES | |
NULL | |
| series | varchar(10) | YES | |
NULL | |
| harga | bigint(11) | YES
| | NULL |
|
+----------+-------------+------+-----+---------+-------+
4 rows in set (0.01 sec)Mengganti Nama Kolom
Dalam memodifikasi nama
kolom contohnya jika kita ingin mengganti nama kolom dari t_car maka caranya :
mysql>
alter table t_car change
harga harga_mobil bigint(11);
Query OK, 2 rows affected
(0.14 sec)
Records: 2 Duplicates: 0
Warnings: 0
mysql> desc t_car;
+-------------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------------+-------------+------+-----+---------+-------+
| id_mobil | varchar(8) | NO
| PRI | NULL | |
| type | varchar(15) | YES | |
NULL | |
| series | varchar(10) | YES | |
NULL | |
| harga_mobil |
bigint(11) | YES | |
NULL | |
+-------------+-------------+------+-----+---------+-------+
4 rows in set (0.01 sec)Menghapus Kolom
Cara untuk menghapus
kolom dengan perintah ALTER TABLE adalah sbb, misal kita akan menghapus salah
satu kolom di t_car, maka caranya :
mysql>
alter table t_car drop
harga_mobil;
Query OK, 2 rows affected
(0.12 sec)
Records: 2 Duplicates: 0
Warnings: 0
mysql> desc t_car;
+----------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+----------+-------------+------+-----+---------+-------+
| id_mobil |
varchar(8) | NO | PRI | NULL |
|
| type | varchar(15) | YES | |
NULL | |
| series | varchar(10) | YES | |
NULL | |
+----------+-------------+------+-----+---------+-------+
3 rows in set (0.01 sec)Menghapus & Menambah Primary Key
Cara untuk menghapus & menambah primary key
dengan perintah ALTER TABLE adalah sbb, misal kita akan menghapus & menambah
primary key di suatu table, maka caranya :
Hapus primary key
mysql> alter table t_pegawai drop primary key;
Query OK, 0 rows affected (0.17 sec)
Records: 0
Duplicates: 0 Warnings: 0
mysql> desc t_pegawai;
+------------+-------------+------+-----+---------+-------+
|
Field | Type | Null | Key | Default | Extra |
+------------+-------------+------+-----+---------+-------+
|
id_peg | varchar(8) | NO
| | NULL |
|
|
nama_peg | varchar(50) | YES | |
NULL | |
|
alamat_peg | varchar(50) | YES | | NULL
| |
+------------+-------------+------+-----+---------+-------+
3 rows in set (0.00 sec)
Tambah
primary key
mysql>
alter table
t_pegawai add
primary key (id_peg);
Query
OK, 0 rows affected (0.53 sec)
Records:
0 Duplicates: 0 Warnings: 0
mysql> desc t_pegawai;
+------------+-------------+------+-----+---------+-------+
| Field
| Type | Null | Key |
Default | Extra |
+------------+-------------+------+-----+---------+-------+
| id_peg
| varchar(8) | NO | PRI | NULL |
|
| nama_peg
| varchar(50) | YES | | NULL
| |
| alamat_peg | varchar(50) | YES | |
NULL | |
+------------+-------------+------+-----+---------+-------+
3 rows in set (0.00 sec)
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