How to add a where clause in a MySQL Insert statem

2019-01-07 23:51发布

This doesn't work:

INSERT INTO users (username, password) VALUES ("Jack","123") WHERE id='1';

Any ideas how to narrow insertion to a particular row by id?

8条回答
时光不老,我们不散
2楼-- · 2019-01-08 00:15
INSERT INTO users (id,username, password) 
VALUES ('1','Jack','123')
ON DUPLICATE KEY UPDATE username='Jack',password='123'

This will work only if the id field is unique/pk (not composite PK though) Also, this will insert if no id of value 1 is found and update otherwise the record with id 1 if it does exists.

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小情绪 Triste *
3楼-- · 2019-01-08 00:16

Try this:

Update users
Set username = 'Jack', password='123'
Where ID = '1'

Or if you're actually trying to insert:

Insert Into users (id, username, password) VALUES ('1', 'Jack','123');
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地球回转人心会变
4楼-- · 2019-01-08 00:17

A conditional insert for use typically in a MySQL script would be:

insert into t1(col1,col2,col3,...)
select val1,val2,val3,...
  from dual
 where [conditional predicate];

You need to use dummy table dual.

In this example, only the second insert-statement will actually insert data into the table:

create table t1(col1 int);
insert into t1(col1) select 1 from dual where 1=0;
insert into t1(col1) select 2 from dual where 1=1;
select * from t1;
+------+
| col1 |
+------+
|    2 |
+------+
1 row in set (0.00 sec)
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唯我独甜
5楼-- · 2019-01-08 00:18

In an insert statement you wouldn't have an existing row to do a where claues on? You are inserting a new row, did you mean to do an update statment?

update users set username='JACK' and password='123' WHERE id='1';
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倾城 Initia
6楼-- · 2019-01-08 00:24

I think you are looking for UPDATE and not insert?

UPDATE `users`
SET `username` = 'Jack', `password` = '123'
WHERE `id` = 1
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冷血范
7楼-- · 2019-01-08 00:26

To add a WHERE clause inside an INSERT statement simply;

INSERT INTO table_name (column1,column2,column3)
SELECT column1, column2, column3 FROM  table_name
WHERE column1 = 'some_value'
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