Strings are sequences of characters and are enclosed with
quotes.
 
The syntax is:
 
[_charset_name]'string' [COLLATE collation_name]
 
For example:
 
'The MariaDB Foundation'
_utf8 'Foundation' COLLATE utf8_unicode_ci;
 
Strings can either be enclosed in single quotes or in double
quotes (the same character must be used to both open and
close the string).
 
The ANSI SQL-standard does not permit double quotes for
enclosing strings, and although MariaDB does by default, if
the MariaDB server has enabled the ANSI_QUOTES_SQL SQL_MODE,
double quotes will be treated as being used for identifiers
instead of strings.
 
Strings that are next to each other are automatically
concatenated. For example:
 
'The ' 'MariaDB ' 'Foundation'
 
and
 
'The MariaDB Foundation'
 
are equivalent.
 
The \ (backslash character) is used to escape characters.
For example:
 
'MariaDB's new features'
 
is not a valid string because of the single quote in the
middle of the string, which is treated as if it closes the
string, but is actually meant as part of the string, an
apostrophe. The backslash character helps in situations like
this:
 
'MariaDB\'s new features'
 
is now a valid string, and if displayed, will appear without
the backslash.
 
SELECT 'MariaDB\'s new features';
+------------------------+
| MariaDB's new features |
+------------------------+
| MariaDB's new features |
+------------------------+
 
Another way to escape the quoting character is repeating it
twice:
 
SELECT 'I''m here', """Double""";
+----------+----------+
| I'm here | "Double" |
+----------+----------+
| I'm here | "Double" |
+----------+----------+
 
Escape sequences
 
There are other escape sequences also. Here is a full list:
 
Escape sequence | Character | 
 
\0 | ASCII NUL (0x00). | 
 
\' | Single quote (“'”). | 
 
\" | Double quote (“"”). | 
 
\b | Backspace. | 
 
\n | Newline, or linefeed,. | 
 
\r | Carriage return. | 
 
\t | Tab. | 
 
\Z | ASCII 26 (Control+Z). See note following the table. | 
 
\\ | Backslash (“\”). | 
 
\% | “%” character. See note following the table. | 
 
\_ | A “_” character. See note following the table. | 
 
Escaping the % and _ characters can be necessary when using
the LIKE operator, which treats them as special characters.
 
The ASCII 26 character (\Z) needs to be escaped when
included in a batch file which needs to be executed in
Windows. The reason is that ASCII 26, in Windows, is the end
of file (EOF).
 
Backslash (\), if not used as an escape character, must
always be escaped. When followed by a character that is not
in the above table, backslashes will simply be ignored.
 

 
 
 
 
 
 
 

URL: https://mariadb.com/kb/en/string-literals/