![]() If the given value is not found, FIND_IN_SET() function returns 0. SELECT FIND_IN_SET('C', 'A,B,C,D') AS result MySQL has a dedicated function FIND_IN_SET() that returns field index if the value is found in a string containing comma-separated values.įor example, the following statement returns one-based index of value C in string A,B,C,D. Search in a column containing comma-separated values I ended up using SUBSTRING_INDEX() to order the results by one of the fields. For example, recently I needed to return a list of values from user-defined function and the only way to do it would be to return a string containing comma-separated values. However, there could be rare cases where the trick above could be useful. In most cases it is better to use a separate lookup table or a column for each field instead of storing data as comma-separated values for later lookup. SUBSTRING_INDEX(SUBSTRING_INDEX(address, ',', 6), ',', -1), 1 Answer Sorted by: SELECT ( SELECT COUNT () FROM userssearchactivity usasq WHERE (usa.countryid, DATE (usa.date)) (untryid, DATE (usasq. One possible workaround to this problem would be to check if the number of fields is greater than or equal to requested index and then the code the above, or return empty string, if the field index is invalid. SELECT name, SUBSTRING_INDEX(SUBSTRING_INDEX(address, ',', 6), ',', -1) AS country FROM employees Then attempt to extract sixth field with SUBSTRING_INDEX(SUBSTRING_INDEX(address, ',', 6), ',', -1) will give us zip code (fifth field) which is wrong. SEPARATOR: This clause sets the string literal inserted between the groups values upon the concatenation process. | Bob Smith | 234 Main Street,Erie,PA,16510 | | name | SUBSTRING_INDEX(address, ',', 6) | SELECT name, SUBSTRING_INDEX(address, ',', 6) FROM employees One thing to be aware about SUBSTRING_INDEX() is that the function returns the whole string if the requested field doesn’t exist.įor example, SUBSTRING_INDEX(address, ',', 6) returns full address. SELECT name FROM employees WHERE SUBSTRING_INDEX(SUBSTRING_INDEX(address, ',', 4), ',', -1)='PA' SELECT name, SUBSTRING_INDEX(SUBSTRING_INDEX(address, ',', 4), ',', -1) AS state FROM employees įinal solution to get all employees working in a certain state is shown below. Because SUBSTRING_INDEX() function allows to use negative values to extract fields counting from the right, we will use this ability to extract the rightmost field containing state abbreviation. Now we know that state would always be the last field in the resulting value. | name | SUBSTRING_INDEX(address, ',', 4) | With SUBSTRING_INDEX(address, ',', 4) function we will be able to extract everything up to the fourth column containing state SELECT SUBSTRING_INDEX(address, ',', 4) FROM employees Suppose we want to find all employees working in a certain state (for example, PA) which is a fourth field in a column holding address as comma-separated values. (1, 'John Doe', '4225 Collins Street,Apt. INSERT INTO employees (id, name, address) VALUES A common usage of the CONCATWS () function is to create a comma-delimited list. SUBSTRING_INDEX() performs a case-sensitive match when searching for delim. If you just use the CONCAT () function, you’d have no separator (unless you explicitly added a separator as an argument between each string argument). If count is negative, everything to the right of the final delimiter (counting from the right) is returned. If count is positive, everything to the left of the final delimiter (counting from the left) is returned. Returns the substring from string str before count occurrences of the delimiter delim. Luckily it has SUBSTRING_INDEX() function that does almost what we need. Surprisingly MySQL doesn’t have a dedicated function for this operations as opposed to split_part in PostgreSQL. Even if it is supplied with numbers, the final output will be. CONCAT(string1, string2, - stringN) Both the input and output types expected by the CONCAT function are Strings. It just contains a comma-separated list of the Strings that needs to be joined.
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