In SQLite, you can use the instr() function to return the position of a given character within a string.
The function only returns the position of the first occurrence of the character (if any).
If the character isn’t found, then it returns 0.
If either of the arguments are NULL, then it returns NULL.
Continue readingIn 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 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.
If you ever need to enable or disable all CHECK constraints in SQLite, you can use the ignore_check_constraints PRAGMA statement.
This pragma statement explicitly enables or disables the enforcement of CHECK constraints. The default setting is off, meaning that CHECK constraints are enforced by default.
In SQLite, you can create a CHECK constraint by adding the applicable code within the CREATE TABLE statement when creating the table.
If a table has a CHECK constraint on it, and you try to insert or update data that violates the CHECK constraint, the operation will fail with an error.
SQLite has an interesting way of handling auto-increment columns. By auto-incrementing columns, I mean columns that increment automatically whenever new data is inserted.
This is similar to an IDENTITY column in SQL Server or an AUTO_INCREMENT column in MySQL.
This article explains how to create AUTOINCREMENT columns in SQLite.
Sometimes you might want to check your “dot command” existing settings in the SQLite command line interface.
Fortunately there’s a .show dot command that returns various settings and their current values.
This article explains how to restore an SQLite database from within the SQLite command line interface.
There are a few ways to restore a database from the SQLite CLI.
One way to do it is to simply attach a new database using the backup file (or a copy of it). Another way to restore a database is to use the .restore dot command to restore the database file to your chosen database within SQLite CLI.
If you’ve ever used the SQLite command line shell, you’re probably familiar with the default command line prompt. Actually, there are two prompts:
sqlite> ...>If you don’t like these prompts, you can always change them with the .prompt dot command.
This article provides a quick demonstration on how to change these prompts.
Continue readingBy default, the SQLite LIKE operator is case-insensitive for ASCII characters. This means it will match uppercase and lowercase characters, regardless of which case you use in your pattern.
However, there is a technique you can use to make it case-sensitive.
Continue reading