大约有 42,000 项符合查询结果（耗时：0.0489秒） [XML]
Foreign Key to non-primary key
...a UNIQUE constraint in another table.
So in your case if you make AnotherID unique, it will be allowed. If you can't apply a unique constraint you're out of luck, but this really does make sense if you think about it.
Although, as has been mentioned, if you have a perfectly good primary key as a ...
Alter MySQL table to add comments on columns
...
try:
ALTER TABLE `user` CHANGE `id` `id` INT( 11 ) COMMENT 'id of user'
share
|
improve this answer
|
follow
|
...
Insert, on duplicate update in PostgreSQL?
...ause. with the following syntax (similar to MySQL)
INSERT INTO the_table (id, column_1, column_2)
VALUES (1, 'A', 'X'), (2, 'B', 'Y'), (3, 'C', 'Z')
ON CONFLICT (id) DO UPDATE
SET column_1 = excluded.column_1,
column_2 = excluded.column_2;
Searching postgresql's email group archives ...
The JPA hashCode() / equals() dilemma
...Read this very nice article on the subject: Don't Let Hibernate Steal Your Identity.
The conclusion of the article goes like this:
Object identity is deceptively hard to implement correctly when
objects are persisted to a database. However, the problems stem
entirely from allowing objects t...
Parse query string into an array
...the second parameter to have the data put in an array instead of into individual variables.
$get_string = "pg_id=2&parent_id=2&document&video";
parse_str($get_string, $get_array);
print_r($get_array);
share
...
How to find all tables that have foreign keys that reference particular table.column and have values
...SAGE
WHERE
REFERENCED_TABLE_NAME = 'X'
AND REFERENCED_COLUMN_NAME = 'X_id';
If you have multiple databases with similar tables/column names you may also wish to limit your query to a particular database:
SELECT *
FROM
KEY_COLUMN_USAGE
WHERE
REFERENCED_TABLE_NAME = 'X'
AND REFERENCED_COL...
How to store arrays in MySQL?
...ables and JOIN them in your queries.
For example:
CREATE TABLE person (
`id` INT NOT NULL PRIMARY KEY,
`name` VARCHAR(50)
);
CREATE TABLE fruits (
`fruit_name` VARCHAR(20) NOT NULL PRIMARY KEY,
`color` VARCHAR(20),
`price` INT
);
CREATE TABLE person_fruit (
`person_id` INT NOT NULL,
`fruit_name`...
How to check if a function exists on a SQL database
...IF EXISTS (SELECT *
FROM sys.objects
WHERE object_id = OBJECT_ID(N'[dbo].[foo]')
AND type IN ( N'FN', N'IF', N'TF', N'FS', N'FT' ))
DROP FUNCTION [dbo].[foo]
GO
This approach to deploying changes means that you need to recreate all permissions on the ...
Difference between id and name attributes in HTML
What is the difference between the id and name attributes? They both seem to serve the same purpose of providing an identifier.
...
How to change a field name in JSON using Jackson
...
Have you tried using @JsonProperty?
@Entity
public class City {
@id
Long id;
String name;
@JsonProperty("label")
public String getName() { return name; }
public void setName(String name){ this.name = name; }
@JsonProperty("value")
public Long getId() { return id; }
...