Table constraints impose restrictions on values in tables

Common uses for these are for representing primary keys and foreign key. You add these to the schema of the table.

CREATE TABLE "riders" (
  "id" INTEGER,
  "name" TEXT,
  PRIMARY KEY ("id")
)

You can have primary keys composed of more than one column, called a joint primary key. Often you’ll see these when you don’t want duplicate combinations in a join table. If you don’t declare an explicit primary

Sources

• sqlite docs on primary keys