📅 最后修改于: 2021-01-04 05:05:19 🧑 作者: Mango
您可以通过提供另一个名称ALIAS暂时重命名表或列。表别名的使用意味着在特定的SQLite语句中重命名表。重命名是一个临时更改，数据库中的实际表名不会更改。
列别名用于重命名表的列，以用于特定的SQLite查询。
以下是表别名的基本语法。
SELECT column1, column2....
FROM table_name AS alias_name
WHERE [condition];
以下是列别名的基本语法。
SELECT column_name AS alias_name
FROM table_name
WHERE [condition];
考虑以下两个表，(a) COMPANY表如下-
sqlite> select * from COMPANY;
ID NAME AGE ADDRESS SALARY
---------- -------------------- ---------- ---------- ----------
1 Paul 32 California 20000.0
2 Allen 25 Texas 15000.0
3 Teddy 23 Norway 20000.0
4 Mark 25 Rich-Mond 65000.0
5 David 27 Texas 85000.0
6 Kim 22 South-Hall 45000.0
7 James 24 Houston 10000.0
(b)另一个表格是部门—
ID DEPT EMP_ID
---------- -------------------- ----------
1 IT Billing 1
2 Engineering 2
3 Finance 7
4 Engineering 3
5 Finance 4
6 Engineering 5
7 Finance 6
现在，下面是表别名的用法，我们分别使用C和D作为COMPANY和DEPARTMENT表的别名-
sqlite> SELECT C.ID, C.NAME, C.AGE, D.DEPT
FROM COMPANY AS C, DEPARTMENT AS D
WHERE C.ID = D.EMP_ID;
上面的SQLite语句将产生以下结果-
ID NAME AGE DEPT
---------- ---------- ---------- ----------
1 Paul 32 IT Billing
2 Allen 25 Engineering
3 Teddy 23 Engineering
4 Mark 25 Finance
5 David 27 Engineering
6 Kim 22 Finance
7 James 24 Finance
考虑使用COLUMN ALIAS的示例，其中COMPANY_ID是ID列的别名，而COMPANY_NAME是name列的别名。
sqlite> SELECT C.ID AS COMPANY_ID, C.NAME AS COMPANY_NAME, C.AGE, D.DEPT
FROM COMPANY AS C, DEPARTMENT AS D
WHERE C.ID = D.EMP_ID;
上面的SQLite语句将产生以下结果-
COMPANY_ID COMPANY_NAME AGE DEPT
---------- ------------ ---------- ----------
1 Paul 32 IT Billing
2 Allen 25 Engineering
3 Teddy 23 Engineering
4 Mark 25 Finance
5 David 27 Engineering
6 Kim 22 Finance
7 James 24 Finance