SQL Queries Execution Order

 Source - https://www.linkedin.com/posts/ginacostag_sql-data-machinelearning-activity-7163529508942241792-3ZT_

The SQL execution order is the sequence in which the different clauses of a SQL query are executed. This order is important because it determines how the data is filtered, grouped, and ordered.

The following is a simplified explanation of the SQL execution order:

• 𝐅𝐑𝐎𝐌/𝐉𝐎𝐈𝐍: The FROM clause specifies the tables from which the data will be retrieved. The JOIN clause can be used to combine data from multiple tables.
• 𝐖𝐇𝐄𝐑𝐄: The WHERE clause is used to filter the data based on specific conditions.
• 𝐆𝐑𝐎𝐔𝐏 𝐁𝐘: The GROUP BY clause is used to group the data based on one or more columns.
• 𝐇𝐀𝐕𝐈𝐍𝐆: The HAVING clause is used to filter the grouped data based on specific conditions.
• 𝐒𝐄𝐋𝐄𝐂𝐓: The SELECT clause specifies the columns that will be returned in the result set.
• 𝐃𝐈𝐒𝐓𝐈𝐍𝐂𝐓: The DISTINCT keyword can be used to ensure that only distinct rows are returned in the result set.
• 𝐎𝐑𝐃𝐄𝐑 𝐁𝐘: The ORDER BY clause is used to sort the result set in ascending or descending order.
• 𝐋𝐈𝐌𝐈𝐓: The LIMIT clause can be used to restrict the number of rows returned.

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