MySQL: Efficiently Selecting Records for the Current Week
To retrieve records for the current week using MySQL, it is essential to understand the concept of week numbering in MySQL. By default, MySQL follows the ISO 8601 week numbering system, where the week starts on Monday and ends on Sunday.
Calculating Week Start and End Dates
One approach to select records for the current week involves calculating the start and end dates of the week based on the current date. This process includes determining the weekday of the current date, calculating the number of days ago to reach the previous Monday, and subsequently computing the Monday and Sunday dates of the current week.
Using YEARWEEK() Function
However, MySQL provides a more efficient method for selecting weekly records using the YEARWEEK() function. The YEARWEEK() function takes a date as input and returns an integer representing the week of the year, where week 1 starts on the first Monday of the year.
Selecting Weekly Records
To select records for the current week, you can use the following query:
<code class="mysql">SELECT * FROM your_table WHERE YEARWEEK(`date`, 1) = YEARWEEK(CURDATE(), 1)</code>
The above query utilizes the YEARWEEK() function with an argument of 1 to force the week numbering to start on Monday. By comparing the computed week number for each record's date with the current week number, the query effectively filters out records that fall outside the current week.
Example
Consider the following table with a date column:
| id | name | date | |---|---|---| | 1 | John | 2023-11-21 | | 2 | Mary | 2023-11-22 | | 3 | Bob | 2023-11-27 | | 4 | Linda | 2023-11-29 |
If the current date is November 22, 2023 (Wednesday), the query above would return only records with dates within the week starting on Monday, November 20th, 2023, and ending on Sunday, November 26th, 2023:
| id | name | date | |---|---|---| | 1 | John | 2023-11-21 | | 2 | Mary | 2023-11-22 |
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