# Case Conversion
__*LOWER function*__
__*LCASE function*__
__*UPPER function*__
__*UCASE function*__
+ `LOWER()/LCASE(), UPPER()/UCASE()` : return a string, and the result is changed to lowercase or uppercase
+ For example:
  + `SELECT lower('TiDB'), upper('TiDB');`  
```
tidb> SELECT lower('TiDB'), upper('TiDB');
+---------------+---------------+
| lower('TiDB') | upper('TiDB') |
+---------------+---------------+
| tidb          | TIDB          |
+---------------+---------------+
```

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- LOWER () /LCASE () return lowercase
- UPPER () /UCASE () return uppercase