![]() The result of this query is: part POSITION('.' IN email) - IN email) simply calculates the length of the substring. Return Value The POSITION () function returns an integer that represents the location of the substring within the string. 2) string The string argument is the string for which the substring is searched. SUBSTRING(email FROM IN email) FOR POSITION('.' IN email) - IN email)) AS substring 1) substring The substring argument is the string that you want to locate. SUBSTRING(email, IN email), POSITION('.' IN email) - IN email)) AS substring You may also want to retrieve a substring that doesn't end at the end of the string but at some specific character, e.g., before '.'. Otherwise, it should be the length of the substring, or you can calculate it using the POSITION() function. If you want the substring to go all the way to the end of the original string, the third argument in the SUBSTRING() function (or the FOR argument) is not needed. The argument column is the column from which you'd like to retrieve the substring it can also be a literal string. To find the index of the specific character, you can use the POSITION(character IN column) function, where character is the specific character at which you'd like to start the substring (here. This time, you're looking for a specific character whose position can vary from row to row. ![]() The result is: use the SUBSTRING() function like in the previous examples. SUBSTRING(email FROM IN email)) AS substring You'd like to display the substring between indexes 2 and 6 (inclusive). SUBSTRING(email, 1) will return the whole string, just as will SUBSTRING(email FROM 1). If you omit it, you'll get the substring that starts at the index in the second argument and goes all the way up to the end of the string. The third argument of the SUBSTRING() function is optional. The argument after the FROM is the starting index, and the argument after the FOR is the substring length. The other notation, SUBSTRING(email FROM 1 FOR 7), does exactly the same. SUBSTRING(email, 1, 7) will return the substrings of the values in the email column that start at the beginning of the strings (first character) and go for seven characters. This means the first character has index 1, the second character has index 2, etc. Watch out! Unlike in some other programming languages, the indexes start at 1, not 0. The third argument is the length of the substring. The second argument is the index of the character at which the substring should begin. The first argument is the string or the column name. ![]() SUBSTRING(email FROM 1 FOR 7) AS substring You'd like to display the first seven characters of each email. In the emails table, there is an email column. How to Extract a Substring From a String in PostgreSQL/MySQL Example 1: 21 In my SQL statement I have to extract a substring from a string at the character.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |