oracle quotation mark escape

When using Oracle for database operations, string splicing is often required, and at this time we will encounter the problem of quotation mark escaping. If you use single quotes or double quotes directly for string concatenation, a syntax error will occur when the string contains single quotes or double quotes. At this time, we need to escape quotes.

In Oracle, quote escaping can be done using the backslash "" symbol. The backslash is an escape character, and when it is placed before a single or double quote, the quote becomes an ordinary character and is no longer part of the string literal. For example:

SELECT 'It''s a sunny day' FROM DUAL;

In the above example, to avoid syntax errors, we use two single quotes to represent one single quote in the string. If you use a single quote directly, a syntax error will occur. In addition, in Oracle, strings need to be wrapped in single quotes.

In addition to using backslashes to escape quotes, you can also use the functions provided by Oracle to escape quotes, for example:

• QUOTE function

The QUOTE function is used to escape special characters in a string. For example:

SELECT QUOTE('It''s a sunny day') FROM DUAL;

In the above example, we use the QUOTE function to escape the single quotes in the string. The running results are as follows:

'It''s a sunny day'

• CHR function

The function of the CHR function is to convert ASCII codes into corresponding characters. For example, if we want to insert a single quote with ASCII code 39 into a string, we can use CHR(39) to convert it. For example:

SELECT 'It' || CHR(39) || 's a sunny day' FROM DUAL;

In the above example, we use the CHR function to convert the character with ASCII code 39 into a single quote. The running results are as follows:

It's a sunny day

To sum up, when performing string splicing operations in Oracle database, we often encounter quotation mark escaping problems. To avoid syntax errors, you can use the backslash symbol or the functions provided by Oracle to escape quotes. Understanding how to escape quotes can greatly improve the efficiency of our code writing and avoid syntax errors, thereby achieving higher program execution efficiency.

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