SQL入門：文字操作

REPLACE

SELECT REPLACE('test', 't', 'T');

出力結果

+---------------------------+
| REPLACE('test', 't', 'T') |
+---------------------------+
| TesT                      |
+---------------------------+
1 row in set (0.00 sec)

SUBSTRING

SELECT SUBSTRING('MySQL8', 3);
SELECT SUBSTRING('MySQL8', 3, 2);
SELECT SUBSTRING('MySQL8' FROM 3);
SELECT SUBSTRING('MySQL8' FROM 3 FOR 2);

出力結果

+------------------------+
| SUBSTRING('MySQL8', 3) |
+------------------------+
| SQL8                   |
+------------------------+
1 row in set (0.00 sec)

+---------------------------+
| SUBSTRING('MySQL8', 3, 2) |
+---------------------------+
| SQ                        |
+---------------------------+
1 row in set (0.00 sec)

+----------------------------+
| SUBSTRING('MySQL8' FROM 3) |
+----------------------------+
| SQL8                       |
+----------------------------+
1 row in set (0.00 sec)

+----------------------------------+
| SUBSTRING('MySQL8' FROM 3 FOR 2) |
+----------------------------------+
| SQ                               |
+----------------------------------+
1 row in set (0.00 sec)

CONCAT

SELECT CONCAT('My', 'SQL', 8);

出力結果

+------------------------+
| CONCAT('My', 'SQL', 8) |
+------------------------+
| MySQL8                 |
+------------------------+
1 row in set (0.00 sec)