What are the oracle wildcards?

Oracle wildcard characters include "%", "_", "[]" and "[^]". Detailed introduction: 1. The wildcard character "%" means matching any character, including zero characters. Using the wildcard character "%" in Oracle can implement fuzzy query. When the wildcard character "%" is used in the query statement, the query will return all characters matching the specified character. Pattern matching string; 2. The wildcard character "_" means matching any single character. In Oracle, the wildcard character "_" can be used to achieve exact matching. When using wildcard characters in query statements, etc.

The wildcard characters used in Oracle database mainly include the following types:

1. Wildcard character "%":

Wildcard character "%" means match any character, including zero characters. Fuzzy queries can be implemented in Oracle using the wildcard "%". When the wildcard character "%" is used in a query statement, the query will return all strings that match the specified pattern. The wildcard character "%" can appear anywhere in the string and can also be used to match multiple characters.

For example, the following query will return all strings starting with "a":

SELECT * FROM table_name WHERE column_name LIKE 'a%';

In this example, the wildcard "%" represents any character starting with "a".

2. Wildcard character "_":

The wildcard character "_" means matching any single character. Exact matching can be achieved by using the wildcard character "_" in Oracle. When the wildcard character "_" is used in a query statement, the query will return all strings that exactly match the specified pattern. The wildcard "_" can only be used to match single characters.

For example, the following query will return all strings containing "ab_":

SELECT * FROM table_name WHERE column_name LIKE 'ab_';

In this example, the wildcard character "_" means matching "ab" Any single character.

3. Wildcard character "[]":

The wildcard character "[]" means matching any single character in square brackets. Exact matching can be achieved using the wildcard character "[]" in Oracle. When the wildcard character "[]" is used in a query statement, the query will return all strings containing any single character in square brackets.

For example, the following query will return all strings starting with "a", "b" or "c":

SELECT * FROM table_name WHERE column_name LIKE '[abc]%';

In this example, the wildcard character "[]" means matching Any character starting with "a", "b", or "c".

4. Wildcard character "[^]":

The wildcard character "[^]" means matching any single character except the characters specified in square brackets. Exact matching can be achieved by using the wildcard character "[^]" in Oracle. When the wildcard character "[^]" is used in a query statement, the query will return all strings that do not contain the characters specified in square brackets.

For example, the following query will return all strings that do not begin with "a", "b", or "c":

SELECT * FROM table_name WHERE column_name NOT LIKE '[abc]%';

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