Let's talk about the use of commonly used escape characters in Oracle
In Oracle database, strings are often used to represent some values, text or some code segments. When these strings contain some special characters, these special characters may cause errors or make the string unreadable. In this case, we need to use escape characters in Oracle to convert these special characters into normal characters.
The escape character consists of a backslash (\) followed by the character to be escaped, such as single quotation mark ('), double quotation mark ("), backslash (\), etc. The following is Some commonly used escape characters in Oracle:
- Single quotation mark ('): In Oracle, single quotation marks are often used to represent strings, and when the string contains single quotation marks, you need to use Two single quotes represent one single quote, for example:
SELECT 'It''s a sunny day.' FROM dual;
The output result is: It's a sunny day.
- Double quotes ("): Double quotes are used to identify the names of objects such as identifiers and column names. The functions of double quotes and single quotes are different. When using double quotes in a string, you need to use two double quotes to represent one double quote, for example:
SELECT "id""name" FROM "employee";
Output The result is: id"name
- Backslash (\): In a string, backslash can be used to escape single quotes ('), double quotes (") and backslashes (\), for example:
SELECT 'John\'s book' FROM dual;
The output result is: John's book
- Line break ( \n): In a string, you can use the escape character "\n" to represent a newline character, for example:
SELECT 'Hello\nworld' FROM dual;
Output The result is:
Hello
world
- Tab character (\t): In a string, you can use the escape character "\t" to represent the tab character , for example:
SELECT 'First name:\tJohn' FROM dual;
The output result is: First name: John
In short, in Oracle, transfer Semantic characters are a very important concept that can help us handle and process some special characters and strings. Proficient use of escape characters can make it easier for us to deal with strings, SQL statements and PL/SQL code.
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