sqlite - 如何在 Sqlite 中指定主键

Question

如何将学生表中的 StudentId 等指定属性定义为 sqlite 中的主键

Answer 1

CREATE TABLE Student(
  id INTEGER PRIMARY KEY,
  first_name TEXT, 
  last_name TEXT
);

从 Sqlite 规范:

One exception to the typelessness of SQLite is a column whose type is INTEGER PRIMARY KEY. (And you must use "INTEGER" not "INT". A column of type INT PRIMARY KEY is typeless just like any other.) INTEGER PRIMARY KEY columns must contain a 32-bit signed integer. Any attempt to insert non-integer data will result in an error.

http://www.sqlite.org/datatypes.html

您还可以在任意 blobish 数据上放置一个主键，例如:

CREATE TABLE Student(id PRIMARY KEY, name)

这有点冒险的原因

INSERT INTO Student(1, "hello") 
INSERT INTO Student("1", "hello") 

将导致两行。

如果你需要对其他东西的唯一约束，你可以尝试使用 Create Index命令