sqlite-创建索引

通用的语法

创建索引

CREATE INDEX index_name ON table_name (column_name);

创建唯一索引

CREATE UNIQUE INDEX index_name ON table_name (column_name)

降序索引

CREATE INDEX PersonIndex ON Person (LastName DESC)

索引多个列

CREATE INDEX PersonIndex ON Person (LastName, FirstName)

索引是否存在

sqlite

select * from sqlite_master

SELECT count(*) FROM sqlite_master WHERE name = 'idx_number_data'