选择所有仅包含大写字母的字段 [英] Select ALL fields that contains only UPPERCASE letters

问题描述

如何选择mysql中仅包含大写字符的字段或不包含任何小写字符的字段?

How do you select a field that contains only uppercase character in mysql or a field that doesn't contain any lower case character?

推荐答案

您可能要使用区分大小写的

You may want to use a case sensitive collation. I believe the default is case insensitive. Example:

CREATE TABLE my_table (
   id int,
   name varchar(50)
) CHARACTER SET latin1 COLLATE latin1_general_cs;

INSERT INTO my_table VALUES (1, 'SomeThing');
INSERT INTO my_table VALUES (2, 'something');
INSERT INTO my_table VALUES (3, 'SOMETHING');
INSERT INTO my_table VALUES (4, 'SOME4THING');

然后:

SELECT * FROM my_table WHERE name REGEXP '^[A-Z]+$';
+------+-----------+
| id   | name      |
+------+-----------+
|    3 | SOMETHING |
+------+-----------+
1 row in set (0.00 sec)

如果您不想对整个表使用区分大小写的排序规则，则还可以使用 @kchau在其他答案中建议

If you don't want to use a case sensitive collation for the whole table, you can also use the COLLATE clause as @kchau suggested in the other answer.

让我们尝试使用不区分大小写的排序规则的表:

Let's try with a table using a case insensitive collation:

CREATE TABLE my_table (
   id int,
   name varchar(50)
) CHARACTER SET latin1 COLLATE latin1_general_ci;

INSERT INTO my_table VALUES (1, 'SomeThing');
INSERT INTO my_table VALUES (2, 'something');
INSERT INTO my_table VALUES (3, 'SOMETHING');
INSERT INTO my_table VALUES (4, 'SOME4THING');

这不能很好地工作:

SELECT * FROM my_table WHERE name REGEXP '^[A-Z]+$';
+------+-----------+
| id   | name      |
+------+-----------+
|    1 | SomeThing |
|    2 | something |
|    3 | SOMETHING |
+------+-----------+
3 rows in set (0.00 sec)

但是我们可以使用COLLATE子句将名称字段整理为区分大小写的整理:

But we can use the COLLATE clause to collate the name field to a case sensitive collation:

SELECT * FROM my_table WHERE (name COLLATE latin1_general_cs) REGEXP '^[A-Z]+$';
+------+-----------+
| id   | name      |
+------+-----------+
|    3 | SOMETHING |
+------+-----------+
1 row in set (0.00 sec)

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