![]() ![]() So this call can be converted to INSTR with 2 parameters in PostgreSQL:įor more information, see Oracle to PostgreSQL Migration. See the following examples: SELECT SUBSTRING ( 'PostgreSQL', 1, 8 ) - PostgreS SELECT SUBSTRING ( 'PostgreSQL', 8 ) - SQL Code language: SQL (Structured Query Language) (sql) In the first statement, we extract a substring that has length of 8 and it is started at the first character of the PostgreSQL string. The last two examples use escape-string syntax and the class-shorthand \s instead of the long form :space: (which loses the outer level of brackets when inside a character class). 4 parameters are specified, but 3rd and 4th have default values SELECT INSTR ( 'abcbcb', 'b', 1, 1 ) FROM dual In this case the user-defined function is not required and POSITION function with 2 parameters can be used in PostgreSQL: The PostgreSQL substring function allows you to extract a substring from a string. Find 2nd occurrence of substring in string starting from 3 position SELECT INSTR4 ( 'abcbcb', 'b', 3, 2 ) Īlso some Oracle code can use INSTR function with 4 parameters, but 3rd and 4th parameters having values of 1. So now you can use this user-defined function for INTR with 4 parameters in PostgreSQL: The required occurrence found IF v_found = 1 THEN 21 In my SQL statement I have to extract a substring from a string at the character. 1 I want to replace substrings in PostgreSQL. ![]() The starting position and length parameters are optional that can be skipped depending on the situation. The SUBSTRING() function accepts three parameters: a string, starting position, and length. Nothing found IF v_pos IS NULL OR v_pos = 0 THEN RETURN v_pos PostgreSQL provides a built-in function named SUBSTRING() that extracts a substring from any specific string. P_start INT, p_occurrence INT ) RETURNS integer AS $$ In PostgreSQL you have to use an user-defined function to find the Nth occurrence of substring:ĬREATE OR REPLACE FUNCTION instr4 (p_str VARCHAR, p_substr VARCHAR , Find 2nd occurrence of substring in string starting from 3 position SELECT INSTR ( 'abcbcb', 'b', 3, 2 ) FROM dual If the pattern contains any parentheses, the substring function returns the text that matches the first parenthesized subexpression. INSTR with 4 parameters starts searching the specified substring from the specified position and returns the position of the specified occurrence of string: ![]()
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