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' |