What operation is used to implement where in sql?

The WHERE statement is used to add filter conditions in the SQL query and select only records that meet the specified conditions. The syntax is: SELECT column name FROM table name WHERE condition. The WHERE statement uses various conditional operators, including: =, <>, >, >=, <, <=, BETWEEN, LIKE, IN. Connectors (AND, OR, NOT) can be used to combine multiple conditions.

WHERE statement in SQL

In SQL, the WHERE statement is used to specify filter conditions in the query, select Records that meet certain conditions.

WHERE statement syntax

<code>SELECT 列名
FROM 表名
WHERE 条件</code>

Conditional operators

The WHERE statement uses various operators to specify conditions, including :

• ##= is equal to
• <> or != is not equal to
• > Greater than
• >= Greater than or equal to
• < Less than
• <= Less than or equal to
• BETWEEN Between
• LIKE Fuzzy match
• IN Belongs to A specified list of values

Example

The following query uses the WHERE statement to select customers older than 25 years old in the customer table:

<code>SELECT * 
FROM customers
WHERE age > 25;<p>Use connectors<strong></strong></p>Connectors (such as AND, OR, NOT) can be used to combine multiple conditions into a WHERE statement. <p></p>
<ul>
<li>AND<strong> Returns true when all conditions are true</strong>
</li>
<li>OR<strong> Returns true when any one of the conditions is true</strong>
</li>
<li>NOT<strong> Invert the result of the condition</strong>
</li>
</ul>
<p>Example<strong></strong></p>The following query uses the AND connector to select the age greater than 25 years old and the city is Client of "New York": <p></p>
<pre class="brush:php;toolbar:false"><code>SELECT * 
FROM customers
WHERE age > 25 AND city = "New York";</code>

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