In SQLite, you can use the random() function to generate a pseudo-random number.
This is great, but the value returned is between -9223372036854775808 and +9223372036854775807.
What if you need a random number between 0 and 10? Or say, 1 and 100?
Fortunately you can do this by combining random() with abs() and the modulo operator.
SQLite has a function called nullif() and another function called ifnull(), each of which serve a different purpose.
nullif() allows you to treat certain values as NULL. You can think of it as “return NULL if …”.ifnull() allows you to replace NULL values with another value. You can think of it as “if NULL, then …”.So they basically do the opposite of each other. One replaces NULL values with another value, and the other replaces another value with NULL.
The SQLite replace() function enables us to replace one string (or part of a string) with another string.
The way it works is that you provide three arguments; the string that contains the substring to replace, the substring within that string to replace, and the string to replace it with.
SQLite includes a PRAGMA statement that allows you to check for foreign key violations on a whole database or a given table.
The statement is PRAGMA foreign_key_check, and it works as follows.
In SQLite, you can use a PRAGMA statement to return a list of foreign keys for a given table.