当一个整数列在sqlite表中被标记为主键时，是否应该为它创建一个索引？ sqlite似乎不会自动为主键列创建索引，但也许它索引它，无论如何，给定其目的？ (我将始终在该列上搜索)。
字符串主键的情况会有什么不同吗？
It does it for you.
INTEGER PRIMARY KEY columns aside,both UNIQUE and PRIMARY KEY constraints are implemented by creating an index in the database (in the same way as a “CREATE UNIQUE INDEX” statement would). Such an index is used like any other index in the database to optimize queries. As a result,there often no advantage (but significant overhead) in creating an index on a set of columns that are already collectively subject to a UNIQUE or PRIMARY KEY constraint.
