How do I create a primary key in SQLite?

How do I create a primary key in SQLite?

The syntax to add a primary key to a table in SQLite is: PRAGMA foreign_keys=off; BEGIN TRANSACTION; ALTER TABLE table_name RENAME TO old_table; CREATE TABLE table_name ( column1 datatype [ NULL | NOT NULL ], column2 datatype [ NULL | NOT NULL ].

How do you create a table in SQLite?

SQLite Create Table

1. First, specify the name of the table that you want to create after the CREATE TABLE keywords.
2. Second, use IF NOT EXISTS option to create a new table if it does not exist.
3. Third, optionally specify the schema_name to which the new table belongs.
4. Fourth, specify the column list of the table.

How do I create a unique key in SQLite?

To define a UNIQUE constraint, you use the UNIQUE keyword followed by one or more columns. You can define a UNIQUE constraint at the column or the table level. Only at the table level, you can define a UNIQUE constraint across multiple columns.

What is a table in SQLite?

Every SQLite database contains a single “schema table” that stores the schema for that database. The schema for a database is a description of all of the other tables, indexes, triggers, and views that are contained within the database.

What is create table if not exists?

The IF NOT EXISTS is optional. It allows you to check if the table that you create already exists in the database. If this is the case, MySQL will ignore the whole statement and will not create any new table. Second, you specify a list of columns of the table in the column_list section, columns are separated by commas.

Does every table need a primary key?

Every table can have (but does not have to have) a primary key. The column or columns defined as the primary key ensure uniqueness in the table; no two rows can have the same key. The primary key of one table may also help to identify records in other tables, and be part of the second table’s primary key.

Can I use text as primary key in SQLite?

I don’t recommend you to use string as primary key. It has more disadvantages as advantages (it has really some advantage?). Usage of number as primary key is much more better (I’m scared to say the best) practise.