What Is the Opposite Of Regexp_like In Oracle?

The opposite of REGEXP_LIKE in Oracle is REGEXP_INSTR. REGEXP_LIKE is used to check if a string matches a regular expression, while REGEXP_INSTR is used to search for a regular expression pattern within a string and returns the position where the pattern is found.

How to filter out strings that fail to satisfy a particular pattern in Oracle?

You can use the REGEXP_LIKE function in Oracle to filter out strings that do not satisfy a particular pattern.

Here's an example query that filters out strings that do not contain only alphanumeric characters:

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SELECT *
FROM your_table
WHERE NOT REGEXP_LIKE(your_column, '^[a-zA-Z0-9]*$');

In this query:

• your_table is the name of your table.
• your_column is the name of the column in your table that contains the strings you want to filter.
• '^[a-zA-Z0-9]*$' is the regular expression pattern that checks if the string contains only alphanumeric characters.

You can adjust the regular expression pattern to suit your specific requirements and filter out strings that do not satisfy a particular pattern.

How to use negation in regular expressions in Oracle?

In Oracle regular expressions, you can use negation by using the caret (^) symbol at the beginning of a character class.

For example, to match any character that is not a lowercase letter, you can use the following regular expression pattern:

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SELECT column_name
FROM table_name
WHERE REGEXP_LIKE(column_name, '[^a-z]');

This will match any character that is not a lowercase letter in the specified column.

You can also use negation in combination with other characters to create more complex patterns.

For example, to match any word that does not start with the letter 'a', you can use the following pattern:

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SELECT column_name
FROM table_name
WHERE REGEXP_LIKE(column_name, '^(?!a)\w+');

In this pattern, the caret (^) symbol is used to match the start of the word, and the (?!a) syntax is used to specify that the word should not start with the letter 'a'. The \w+ pattern is used to match one or more word characters following the specified condition.

Overall, negation can be a useful tool in Oracle regular expressions for specifying patterns that should not be matched in your data.

How to filter out strings that do not meet a certain pattern in Oracle?

One way to filter out strings that do not meet a certain pattern in Oracle is to use the REGEXP_LIKE function in a WHERE clause.

For example, if you wanted to filter out strings that do not contain the pattern 'apple' anywhere in the string, you could write a query like this:

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SELECT column_name
FROM table_name
WHERE NOT REGEXP_LIKE(column_name, 'apple')

This query will return only the rows where the column does not contain the pattern 'apple'. You can adjust the regular expression pattern to match the specific pattern you are looking for.