mysql：insert ignore、insert和replace區別
insert 報錯 插入 insert into names(name, age) values(“小明”, 23);
insert ignore 忽略 插入 insert ignore into names(name, age) values(“小明”, 24);
replace 替換 插入 replace into names(name, age) values(“小明”, 25);
表要求：有PrimaryKey，或者unique索引
結果：表id都會自增
測試代碼
創建表
CREATE TABLE names(
id INT(10) PRIMARY KEY AUTO_INCREMENT,
name VARCHAR(255) UNIQUE,
age INT(10)
)
插入數據
mysql> insert into names(name, age) values("小明", 24);
mysql> insert into names(name, age) values("大紅", 24);
mysql> insert into names(name, age) values("大壯", 24);
mysql> insert into names(name, age) values("秀英", 24);
mysql> select * from names;
+----+--------+------+
| id | name | age |
+----+--------+------+
| 1 | 小明 | 24 |
| 2 | 大紅 | 24 |
| 3 | 大壯 | 24 |
| 4 | 秀英 | 24 |
+----+--------+------+
insert
插入已存在, id會自增，但是插入不成功，會報錯
mysql> insert into names(name, age) values("小明", 23);
ERROR 1062 (23000): Duplicate entry '小明' for key 'name'
replace
已存在替換，刪除原來的記錄，添加新的記錄
mysql> replace into names(name, age) values("小明", 23);
Query OK, 2 rows affected (0.00 sec)
mysql> select * from names;
+----+--------+------+
| id | name | age |
+----+--------+------+
| 2 | 大紅 | 24 |
| 3 | 大壯 | 24 |
| 4 | 秀英 | 24 |
| 6 | 小明 | 23 |
+----+--------+------+
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不存在替換，添加新的記錄
mysql> replace into names(name, age) values("大名", 23);
Query OK, 1 row affected (0.00 sec)
mysql> select * from names;
+----+--------+------+
| id | name | age |
+----+--------+------+
| 2 | 大紅 | 24 |
| 3 | 大壯 | 24 |
| 4 | 秀英 | 24 |
| 6 | 小明 | 23 |
| 7 | 大名 | 23 |
+----+--------+------+
insert ignore
插入已存在，忽略新插入的記錄，id會自增，不會報錯
mysql> insert ignore into names(name, age) values("大壯", 25);
Query OK, 0 rows affected, 1 warning (0.00 sec)
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插入不存在，添加新的記錄
mysql> insert ignore into names(name, age) values("壯壯", 25);
Query OK, 1 row affected (0.01 sec)
mysql> select * from names;
+----+--------+------+
| id | name | age |
+----+--------+------+
| 2 | 大紅 | 24 |
| 3 | 大壯 | 24 |
| 4 | 秀英 | 24 |
| 6 | 小明 | 23 |
| 7 | 大名 | 23 |
| 10 | 壯壯 | 25 |
+----+--------+------+
-------------------------
更多參考：
https://www.mysqltutorial.org/mysql-insert-ignore/