Sqlite—查詢語句(Select)

基本語法如下

sqlite> select * from tb_user;
sqlite> select userid,username from tb_user;

格式化的查詢輸出

sqlite> .header on
sqlite> .mode column
sqlite> select * from tb_user;

設置輸出列的寬度

sqlite> .width 10, 20, 10
sqlite> select * from tb_user;

SQLite 的 ORDER BY 子句是用來基於一個或多個列按升序或降序順序排列數據。

基本語法：SELECT column-list FROM table_name [WHERE condition] [ORDER BY column1, column2, .. columnN] [ASC | DESC];

sqlite> select * from tb_user order by name asc;        -- 結果按 name 升序排序：
sqlite> select * from tb_user order by name desc;       -- 結果按 name 降序排序：
sqlite> select * from tb_user order by name,age asc;    -- 結果按 name 和 age升序排序：

SQLite 的 Distinct 關鍵字

基本語法：SELECT DISTINCT column1, column2,.....columnN FROM table_name WHERE [condition]

sqlite> select distinct name from tb_user;
sqlite> select distinct name,age from tb_user;
sqlite> select distinct name,age from tb_user where name="liu";