One check constraint or multiple check constraints?

Question

Any suggestions on whether less verification restrictions are better or more? How should they be grouped, if at all?

Suppose I have 3 columns which VARCHAR2(1 BYTE), each of which is the flag 'T' / 'F'. I want to add a validation constraint to each column, indicating that only characters are allowed IN ('T', 'F').

Should I have 3 separate control constraints, one for each column:

COL_1 IN ('T', 'F')

COL_2 IN ('T', 'F') 

COL_3 IN ('T', 'F')

Or one check constraint:

COL_1 IN ('T', 'F') AND COL_2 IN ('T', 'F') AND COL_3 IN ('T', 'F')

My thoughts are that it is best to keep these three separate from each other, since the columns are logically not connected to each other. The only case where I would have a validation constraint that validates more than one column is if there was some connection between the value in one and the value in the other, for example:

(PARENT_CNT > 0 AND PRIMARY_PARENT IS NOT NULL) OR (PARENT_CNT = 0 AND PRIMARY_PARENT IS NULL)

Answer 1

Keep separate, these are different columns. In addition, an error check name will be displayed in the error message, and you will better know where the problem is. The future developer will confuse why they are all together, or do not notice them, because they are in a different column.

Answer 2

varchar . , . , 0 = False = True. ( ).

: 3 ( , ). , .

Answer 3

, .

, , , . null, null. , , .

Example: I have two columns BatchId int NULLand SuperBatchId int NULL. Then my control limit

CHECK((BatchId  IS NOT NULL) OR (SuperBatchId  IS NOT NULL))

This is an example of a check constraint for two columns.