CREATE TABLE jooksjad (ID int NOT NULL AUTO_INCREMENT, eesnimi varchar(30), lemmiktoidu_id int, PRIMARY KEY(ID));

mysql> CREATE TABLE toidud(ID int NOT NULL AUTO_INCREMENT, nimetus varchar(30), PRIMARY KEY(ID));
mysql> insert into toidud(nimetus) values ('Hernesupp');
Query OK, 1 row affected (0.10 sec)

mysql> INSERT INTO jooksjad(eesnimi, lemmiktoidu_id) values ('Juku', 1);
Query OK, 1 row affected (0.00 sec)

mysql> select * from jooksjad;
+----+---------+----------------+
| ID | eesnimi | lemmiktoidu_id |
+----+---------+----------------+
|  1 | Juku    |              1 |
|  2 | Kati    |              1 |
|  3 | Mati    |           NULL |
+----+---------+----------------+
3 rows in set (0.01 sec)

mysql> SELECT * FROM toidud;
+----+------------+
| ID | nimetus    |
+----+------------+
|  1 | Hernesupp  |
|  2 | Kapsasupp  |
|  3 | Pannkoogid |
+----+------------+
3 rows in set (0.01 sec)


mysql> SELECT * FROM jooksjad, toidud WHERE jooksjad.lemmiktoidu_id=toidud.ID;

+----+---------+----------------+----+-----------+
| ID | eesnimi | lemmiktoidu_id | ID | nimetus   |
+----+---------+----------------+----+-----------+
|  1 | Juku    |              1 |  1 | Hernesupp |
|  2 | Kati    |              1 |  1 | Hernesupp |
+----+---------+----------------+----+-----------+
2 rows in set (0.06 sec)

mysql> SELECT * FROM jooksjad LEFT JOIN toidud ON toidud.id=jooksjad.lemmiktoidu_id;
+----+---------+----------------+------+-----------+
| ID | eesnimi | lemmiktoidu_id | ID   | nimetus   |
+----+---------+----------------+------+-----------+
|  1 | Juku    |              1 |    1 | Hernesupp |
|  2 | Kati    |              1 |    1 | Hernesupp |
|  3 | Mati    |           NULL | NULL | NULL      |
+----+---------+----------------+------+-----------+
3 rows in set (0.00 sec)


mysql> select * from jooksjad where eesnimi like 'J%';
+----+---------+----------------+
| ID | eesnimi | lemmiktoidu_id |
+----+---------+----------------+
|  1 | Juku    |              1 |
+----+---------+----------------+
1 row in set (0.01 sec)


mysql> select * from jooksjad where eesnimi like 'J_ku';
+----+---------+----------------+
| ID | eesnimi | lemmiktoidu_id |
+----+---------+----------------+
|  1 | Juku    |              1 |
+----+---------+----------------+
1 row in set (0.00 sec)

mysql> select * from jooksjad where eesnimi like 'J_k';
Empty set (0.01 sec)

mysql> select eesnimi, length(eesnimi) from jooksjad;
+---------+-----------------+
| eesnimi | length(eesnimi) |
+---------+-----------------+
| Juku    |               4 |
| Kati    |               4 |
| Mati    |               4 |
+---------+-----------------+
3 rows in set (0.08 sec)

mysql> select eesnimi, left(eesnimi, 1) from jooksjad;
+---------+------------------+
| eesnimi | left(eesnimi, 1) |
+---------+------------------+
| Juku    | J                |
| Kati    | K                |
| Mati    | M                |
+---------+------------------+
3 rows in set (0.07 sec)