Priority of and and or in sql

In SQL queries, the AND operator has higher precedence than the OR operator, which means the AND operator will be evaluated first, followed by the OR operator.

The precedence of AND and OR operators in SQL

In SQL queries, the AND and OR operators use Used to combine multiple conditions to control the scope of the result set. The precedence of these operators is important because it determines the order in which conditions are evaluated.

Priority

In SQL, the AND operator has higher precedence than the OR operator. This means that the AND operator will be evaluated first, and the OR operator will be evaluated after the AND operator.

Example

The following query example shows the precedence of AND and OR operators:

<code class="sql">SELECT * 
FROM table_name
WHERE (column1 = 'value1' AND column2 = 'value2') OR column3 = 'value3';</code>

In this query, parentheses separate the AND operator The grouping precedence of the operator is raised above that of the OR operator. This means that the query will first evaluate the conditions within the parentheses and then evaluate the OR operator.

Evaluation order

According to the above priority, the query will evaluate the conditions in the following order:

1. column1 = ' value1'
2. column2 = 'value2'
3. (column1 = 'value1' AND column2 = 'value2')
4. column3 = 'value3'
5. (column1 = 'value1' AND column2 = 'value2') OR column3 = 'value3'

Result

Ultimately, the query will return rows that meet one of the following conditions:

• column1 = 'value1' And column2 = 'value2'
• column3 = 'value3'

##Important Tips

In order to ensure the correctness of the query, be sure to pay attention to the priority of the AND and OR operators. If you need to change the priority, you can use parentheses for grouping.

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