选择查询根据mysql中不同的列值获取5 5行

Question

I have an Invoice table which contains invoice data in each row where an invoice can be in different state such as due, overdue, disputed and partially paid. Below is the table structure:

Invoice_no	due_state	disputed_state	paid_state
inv1	due	dispute_none	paid_none
inv2	overdue	disputed	partially_paid
inv3	due	disputed	partially_paid

I need to fetch 5 invoices which are in due state, 5 invoices which are in overdue state, 5 invoices which are in disputed state and 5 invoices which are in partially paid state in single mysql query.

Currently I'm running 5 different sqls to fetch results for each states. Please help me to create one sql to fetch invoices for each states in a single sql query.

I'm using mysql database. Currently I'm doing it as

Select * from table where due_state = 'due' limit 5;

Select * from table where due_state = 'overdue' limit 5;

Select * from table where diputed_state = 'disputed' limit 5;

Select * from table where paid_state = 'partially_paid' limit 5

Thanks in advance.

Answer 1

You can apply:

• UNION ALL if you want 20 records with potential duplicates
• UNION if you are allowing less than 20 unique records, among which there can be records that satisfy more conditions at the same time.

Select * from table where due_state = 'due' limit 5
UNION [ALL]
Select * from table where due_state = 'overdue' limit 5
UNION [ALL]
Select * from table where diputed_state = 'disputed' limit 5
UNION [ALL]
Select * from table where paid_state = 'partially_paid' limit 5

Note: [ALL] is the optional keyword to be added without brackets or removed completely from the final query.