How many ways are there to write mysql comments?

There are three types of mysql comments, namely: 1. Single-line comments using "#comment content"; 2. Single-line comments using "-- comment content", "--" and comment content There must be spaces between; 3. Use "/* comment content*/" for multi-line comments.

MySQL generally has three comment styles. They are:

1. Single-line comments can use "# "

select 1 as cname; #this is a comment 
+-------+
| cname |
+-------+
|     1 |
+-------+

-- (#后面直接根的就是注释)

2. The second way to write a single-line comment is to use "-- "

Note that in this style "--[space]" is There is a space between "--" and the comment.

select 123; -- this is a comment 
+-----+
| 123 |
+-----+
| 123 |
+-----+

-- 注意啊-- 后面是要有一个空格的

3. Multi-line comments can be made with /**/

mysql> select 123; /* this is a comment */+-----+
| 123 |
+-----+
| 123 |
+-----+1 row in set (0.00 sec)

mysql> select 1+ /* this is a
                          comment */ 1;+-------+
| 1+  1 |
+-------+
|     2 |
+-------+1 row in set (0.00 sec)

Recommended tutorial: mysql video tutorial

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