This page contains a list of aggregate functions that are available in SQLite by default.
DBMS
Database Management Systems
How to Enable/Disable CHECK Constraints in SQLite
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.
Create a CHECK Constraint in SQLite
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.
Create an Auto-Increment Column in SQLite
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.
Add a Foreign Key to an Existing Table in SQLite
SQLite supports a very limited subset of the ALTER TABLE statement. The only things you can do with ALTER TABLE in SQLite is rename a table, rename a column within a table, or add a new column to an existing table.
In other words, you can’t use ALTER TABLE to add a foreign key to an existing table like you can in other database management systems.
Therefore, the only way you can “add” a foreign key to an existing table in SQLite is to create a new table with a foreign key, then transfer the data to the new table.
There’s more than one way to do this, but there is a recommended way.
Create a Foreign Key in SQLite
When you create a table in SQLite, you can also create a foreign key in order to establish a relationship with another table.
This article provides an example of creating a foreign key when creating a table in SQLite.
Restore an SQLite Database
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.
How Group_Concat() Works in SQLite
SQLite has a group_concat() function that allows you to concatenate multiple results returned for a column into one.
This is sometimes referred to as “string aggregation”.
For example, when querying a database, instead of having each column’s value output in a new row, you can use group_concat() to have them output as a comma separated list.