IBNgemini:
I'm getting an error which says (cannot update or add a child row:a foreign key constraint fails).
I created two database table User and question.
TABLE user
User_Id. INT A.I primary key,
user_name .varchar
user_dob,
user_date, ..

Table question
Question_Id INT A.I,primary key,
Question_sub, varchar,
Question_date, date,
user_id INT (foreign key referencing user(user_I'd))
The problem is that whenever I try to insert into table (question) manually using phpadmin,it will be successful but whenever I try to insert into table (question) through php mysql always return the constraint fails error...

Bolaji21:

Copy and paste the error here for details.
But constraint error means you're trying to insert into a column value greater than the constraint
For example, say you set the Question_sub as VARCHAR(20). if you're trying to insert a string in that column that's more than 20 characters, you'll get that error. A common error is trying to save a string in an INT column or a string in a DATE column

IBNgemini:

Bolaji21:
The columns in the insert query doesn't match the table schema you posted earlier.
Also, change the quest_date column type to TIMESTAMP
quest_title column doesn't exist in the schema you posted earlier, but you're using it in your code

The mysql error you posted is pointing to foreign key, i assume you know what that is cos you must have added it yourself.
The data type for the child column must match the parent column exactly. For example, if user_id is a foreign key in question table and it's type INT, ID in user table must be INT.