how to drop a unique constraint in sql
SHOW CREATE TABLE [tableName]
-- Find the constraintID after CONSTRAINT 'constraintID'
ALTER TABLE [tableName] DROP FOREIGN KEY constraintID
how to drop a unique constraint in sql
SHOW CREATE TABLE [tableName]
-- Find the constraintID after CONSTRAINT 'constraintID'
ALTER TABLE [tableName] DROP FOREIGN KEY constraintID
sql make sure every user is unqiuew
create table user(
user_id INT auto_increment PRIMARY KEY,
username varchar(50) not null,
avator varchar(50),
gender boolean not null,
phone varchar(20),
unique(username)
);
create table journey(
id INT auto_increment PRIMARY KEY,
start varchar(100) not null,
dest varchar(100) not null,
time date not null,
person INT,
user_id INT not null,
foreign key(user_id) references user(user_id)
);
Copyright © 2021 Codeinu
Forgot your account's password or having trouble logging into your Account? Don't worry, we'll help you to get back your account. Enter your email address and we'll send you a recovery link to reset your password. If you are experiencing problems resetting your password contact us