![]() ![]() In this tutorial, you have learned how to use the PostgreSQL REGEXP_REPLACE() function to replace substrings that match a regular expression with a new substring. The following picture illustrates the output: SELECT REGEXP_REPLACE( 'This is a test string', '( )', ' ') Code language: JavaScript ( javascript ) If anyone can help me understand what I'm doing wrong it would me much appreciated. I'm using PSQL 9.0.4 I've tested my regex outside of PG and it works perfectly. The following example removes unwanted spaces that appear more than once in a string. 1 I'm trying to create a regex to find (and then eventually replace) parts of strings in a PG DB. Similarly, you can remove all digits in the source string by using the following statement: SELECT REGEXP_REPLACE( 'ABC12345xyz', ']', '', 'g') Code language: JavaScript ( javascript )Īnd the output is: 'ABCxyz' Code language: JavaScript ( javascript ) 'g' instructs the function to remove all alphabets, not just the first one.The output is: '12345' Code language: JavaScript ( javascript ) The following statement removes all alphabets e.g., A, B, C, etc from the source string: SELECT REGEXP_REPLACE( 'ABC12345xyz', ']', '', 'g') Code language: JavaScript ( javascript ) Imagine you have string data with mixed alphabets and digits as follows: ABC12345xyz The output is of the statement is: 'Doe, John' Code language: JavaScript ( javascript ) To do this, you can use the REGEXP_REPLACE() function as shown below: SELECT REGEXP_REPLACE( 'John Doe', '(.*) (.*)', '\2, \1') Code language: JavaScript ( javascript ) ![]() Suppose, you have a name of a person in the following format: first_name last_nameĪnd you want to rearrange the this name as follows for the reporting purpose. Let’s see some examples to understand how the REGEXP_REPLACE() function works. The PostgreSQL REGEXP_REPLACE() function returns a new string with the substrings, which match a regular expression pattern, replaced by a new substring. The flags argument is one or more character that controls the matching behavior of the function e.g., i allows case-insensitive matching, n enables matching any character and also the newline character. ![]() The replacement_string is a string that to replace the substrings which match the regular expression pattern. The pattern is a POSIX regular expression for matching substrings that should be replaced. The source is a string that replacement should be taken place. The REGEXP_REPLACE() function accepts four arguments: The syntax of the PostgreSQL REGEXP_REPLACE() function is as follows: REGEXP_REPLACE( source, pattern, replacement_string, ) Code language: CSS ( css ) Arguments Note that if you want to perform simple string replacement, you can use the REPLACE() function. The PostgreSQL REGEXP_REPLACE() function replaces substrings that match a POSIX regular expression by a new substring. Summary: in this tutorial, you will learn how to use the PostgreSQL REGEXP_REPLACE() function to replace strings that match a regular expression. ![]()
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