Why does MySQL evaluate 'TRUE or TRUE and FALSE' as true?

MySQL evaluates "TRUE or TRUE and FALSE" as true because AND has a higher priority than OR, i.e. AND is evaluated before OR.

MySQL evaluates the above statement as follows. The AND operator −

(TRUE or (TRUE AND FALSE))

statement (TRUE AND FALSE) is evaluated first and the result is FALSE. Then the second statement The evaluation is as follows -

(TRUE or FALSE)

The above statement gives a result of TRUE.

Let’s implement it one by one-

mysql> select (TRUE AND FALSE);
+------------------+
| (TRUE AND FALSE) |
+------------------+
|                0 |
+------------------+
1 row in set (0.00 sec)

Now we can put the above result in place of AND condition−

mysql> select (TRUE or FALSE);
+-----------------+
| (TRUE or FALSE) |
+-----------------+
|               1 |
+-----------------+
1 row in set (0.00 sec)

Now check the whole condition again−

mysql> select (TRUE or TRUE and FALSE);

This will produce the following output−

+--------------------------+
| (TRUE or TRUE and FALSE) |
+--------------------------+
|                        1 |
+--------------------------+
1 row in set (0.00 sec)

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