【数据库差异研究】update与delete使用表别名的研究

时间:2024-10-06 19:04:35

目录

⚛️总结

☪️1 Update

♋1.1 测试用例UPDATE users as a SET a.age = 111 WHERE a.name = 'Alice';

♏1.2 测试用例UPDATE users as a SET a.age = 111 WHERE name = 'Alice';

♐1.3 测试用例UPDATE users as a SET age = 111 WHERE a.name = 'Alice';

♑1.4 测试用例UPDATE users as a SET age = 111 WHERE name = 'Alice';

☪️2 delete

♉2.1 测试用例delete users as a from a WHERE a.name = 'Alice';

♈2.2 测试用例delete users as a from a WHERE name = 'Alice';


⚛️总结

Update

SQL语句示例 Oracle SQLite PostgreSQL MYSQL & mariadb
UPDATE users as a SET a.age = 111 WHERE a.name = 'Alice'; 报错 报错 报错 正常执行
UPDATE users as a SET a.age = 111 WHERE name = 'Alice'; 报错 报错 报错 正常执行
UPDATE users as a SET age = 111 WHERE a.name = 'Alice'; 报错 正常执行 正常执行 正常执行
UPDATE users as a SET age = 111 WHERE name = 'Alice'; 报错 正常执行 正常执行 正常执行

Delete

SQL语句示例 Oracle SQLite PostgreSQL MYSQL & mariadb
delete from users as a WHERE a.name = 'Alice'; 报错 报错 报错 报错
delete from users as a WHERE name = 'Alice'; 报错 报错 报错 报错

☪️1 Update

♋1.1 测试用例UPDATE users as a SET a.age = 111 WHERE a.name = 'Alice';

UPDATE users as a SET a.age = 111 WHERE a.name = 'Alice';

CREATE TABLE users (
    name VARCHAR(255) NOT NULL,
    age INT
);

INSERT INTO users (name, age) VALUES ('Alice', 25);
INSERT INTO users (name, age) VALUES ('Bob', 30);
INSERT INTO users (name, age) VALUES ('Charlie', 35);
INSERT INTO users (name, age) VALUES ('Alice', 40);

SELECT * FROM users;
UPDATE users as a SET a.age = 111 WHERE a.name = 'Alice';
SELECT * FROM users;

修改前表内容如下:

name age
Alice 25
Bob 30
Charlie 35
Alice 40

1 ORACLE

执行报错

ORA-00971: missing SET keyword 

之后查询表内容未发生变化,如下:

name age
Alice 25
Bob 30
Charlie 35
Alice 40

2 sqlite

执行报错

Error: near line 12: near ".": syntax error

之后查询表内容未发生变化,如下:

name age
Alice 25
Bob 30
Charlie 35
Alice 40

3 PG

执行报错

psql:commands.sql:12: ERROR:  column "a" of relation "users" does not exist
LINE 1: UPDATE users as a SET a.age = 111 WHERE a.name = 'Alice';

之后查询表内容未发生变化,如下:

name age
Alice 25
Bob 30
Charlie 35
Alice 40

4 MYSQL & mariadb

执行正常

后表内容已经更新,如下:

name age
Alice 111
Bob 30
Charlie 35
Alice 111

♏1.2 测试用例UPDATE users as a SET a.age = 111 WHERE name = 'Alice';

UPDATE users as a SET a.age = 111 WHERE name = 'Alice';

CREATE TABLE users (
    name VARCHAR(255) NOT NULL,
    age INT
);

INSERT INTO users (name, age) VALUES ('Alice', 25);
INSERT INTO users (name, age) VALUES ('Bob', 30);
INSERT INTO users (name, age) VALUES ('Charlie', 35);
INSERT INTO users (name, age) VALUES ('Alice', 40);

SELECT * FROM users;
UPDATE users as a SET a.age = 111 WHERE name = 'Alice';
SELECT * FROM users;

修改前表内容如下:

name age
Alice 25
Bob 30
Charlie 35
Alice 40

1 ORACLE

执行报错

ORA-00971: missing SET keyword 

之后查询表内容未发生变化,如下:

name age
Alice 25
Bob 30
Charlie 35
Alice 40

2 sqlite

 执行报错

Error: near line 12: near ".": syntax error

之后查询表内容未发生变化,如下:

name age
Alice 25
Bob 30
Charlie 35
Alice 40

3 PG

  执行报错

psql:commands.sql:12: ERROR:  column "a" of relation "users" does not exist
LINE 1: UPDATE users as a SET a.age = 111 WHERE name = 'Alice';

之后查询表内容未发生变化,如下:

name age
Alice 25
Bob 30
Charlie 35
Alice 40

4 MYSQL & mariadb

执行正常

后表内容已经更新,如下:

name age
Alice 111
Bob 30
Charlie 35
Alice 111

♐1.3 测试用例UPDATE users as a SET age = 111 WHERE a.name = 'Alice';

UPDATE users as a SET age = 111 WHERE a.name = 'Alice';

CREATE TABLE users (
    name VARCHAR(255) NOT NULL,
    age INT
);

INSERT INTO users (name, age) VALUES ('Alice', 25);
INSERT INTO users (name, age) VALUES ('Bob', 30);
INSERT INTO users (name, age) VALUES ('Charlie', 35);
INSERT INTO users (name, age) VALUES ('Alice', 40);

SELECT * FROM users;
UPDATE users as a SET age = 111 WHERE a.name = 'Alice';
SELECT * FROM users;

修改前表内容如下:

name age
Alice 25
Bob 30
Charlie 35
Alice 40

1 ORACLE

 执行报错

ORA-00971: missing SET keyword 

之后查询表内容未发生变化,如下:

name age
Alice 25
Bob 30
Charlie 35
Alice 40

2 sqlite

执行正常

后表内容已经更新,如下:

name age
Alice 111
Bob 30
Charlie 35
Alice 111

3 PG

执行正常

后表内容已经更新,如下:

name age
Bob 30
Charlie 35
Alice 111
Alice 111

4 MYSQL & mariadb

执行正常

后表内容已经更新,如下:

name age
Alice 111
Bob 30
Charlie 35
Alice 111

♑1.4 测试用例UPDATE users as a SET age = 111 WHERE name = 'Alice';

UPDATE users as a SET age = 111 WHERE name = 'Alice';

CREATE TABLE users (
    name VARCHAR(255) NOT NULL,
    age INT
);

INSERT INTO users (name, age) VALUES ('Alice', 25);
INSERT INTO users (name, age) VALUES ('Bob', 30);
INSERT INTO users (name, age) VALUES ('Charlie', 35);
INSERT INTO users (name, age) VALUES ('Alice', 40);

SELECT * FROM users;
UPDATE users as a SET age = 111 WHERE name = 'Alice';
SELECT * FROM users;

修改前表内容如下:

name age
Alice 25
Bob 30
Charlie 35
Alice 40

1 ORACLE

 执行报错

ORA-00971: missing SET keyword 

之后查询表内容未发生变化,如下:

name age
Alice 25
Bob 30
Charlie 35
Alice 40

2 sqlite

执行正常

后表内容已经更新,如下:

name age
Alice 111
Bob 30
Charlie 35
Alice 111

3 PG

执行正常

后表内容已经更新,如下:

name age
Bob 30
Charlie 35
Alice 111
Alice 111

4 MYSQL & mariadb

执行正常

后表内容已经更新,如下:

name age
Alice 111
Bob 30
Charlie 35
Alice 111

☪️2 delete

♉2.1 测试用例delete users as a from a WHERE a.name = 'Alice';

delete users as a from a WHERE a.name = 'Alice';

CREATE TABLE users (
    name VARCHAR(255) NOT NULL,
    age INT
);

INSERT INTO users (name, age) VALUES ('Alice', 25);
INSERT INTO users (name, age) VALUES ('Bob', 30);
INSERT INTO users (name, age) VALUES ('Charlie', 35);
INSERT INTO users (name, age) VALUES ('Alice', 40);

SELECT * FROM users;
delete users as a from a WHERE a.name = 'Alice';
SELECT * FROM users;

修改前表内容如下:

name age
Alice 25
Bob 30
Charlie 35
Alice 40

1 ORACLE

 执行报错

ORA-03048: SQL reserved word 'AS' is not syntactically valid following 'delete
users '

之后查询表内容未发生变化,如下:

name age
Alice 25
Bob 30
Charlie 35
Alice 40

2 sqlite

 执行报错

Error: near line 12: near "users": syntax error

之后查询表内容未发生变化,如下:

name age
Alice 25
Bob 30
Charlie 35
Alice 40

3 PG

 执行报错

psql:commands.sql:12: ERROR:  syntax error at or near "users"
LINE 1: delete users as a from a WHERE a.name = 'Alice';

 之后查询表内容未发生变化,如下:

name age
Alice 25
Bob 30
Charlie 35
Alice 40

4 MYSQL & mariadb

 执行报错

ERROR 1064 (42000) at line 12: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'as a from a WHERE a.name = 'Alice'' at line 1

 之后查询表内容未发生变化,如下:

name age
Alice 25
Bob 30
Charlie 35
Alice 40

♈2.2 测试用例delete users as a from a WHERE name = 'Alice';

delete users as a from a WHERE name = 'Alice';

CREATE TABLE users (
    name VARCHAR(255) NOT NULL,
    age INT
);

INSERT INTO users (name, age) VALUES ('Alice', 25);
INSERT INTO users (name, age) VALUES ('Bob', 30);
INSERT INTO users (name, age) VALUES ('Charlie', 35);
INSERT INTO users (name, age) VALUES ('Alice', 40);

SELECT * FROM users;
delete users as a from a WHERE name = 'Alice';
SELECT * FROM users;

修改前表内容如下:

name age
Alice 25
Bob 30
Charlie 35
Alice 40

1 ORACLE

 执行报错

ORA-03048: SQL reserved word 'AS' is not syntactically valid following 'delete
users '

之后查询表内容未发生变化,如下:

name age
Alice 25
Bob 30
Charlie 35
Alice 40

2 sqlite

 执行报错

Error: near line 12: near "users": syntax error

之后查询表内容未发生变化,如下:

name age
Alice 25
Bob 30
Charlie 35
Alice 40

3 PG

 执行报错

psql:commands.sql:12: ERROR:  syntax error at or near "users"
LINE 1: delete users as a from a WHERE name = 'Alice';

 之后查询表内容未发生变化,如下:

name age
Alice 25
Bob 30
Charlie 35
Alice 40

4 MYSQL & mariadb

 执行报错

ERROR 1064 (42000) at line 12: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'as a from a WHERE name = 'Alice'' at line 1

 之后查询表内容未发生变化,如下:

name age
Alice 25
Bob 30
Charlie 35
Alice 40