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POmerging two SELECT queries
 

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    <p>I am either getting old or the queries that I need to write are getting more and more complicated. The following query will get all the <code>tasks</code> associated with the user.</p> <pre><code>"SELECT `date` FROM `tasks` WHERE `user_id`= 1;" </code></pre> <p>The <code>tasks</code> table is (<code>id</code>, <code>date</code>, <code>user_id</code>, <code>url_id</code>);</p> <p>Now, I need to get as well records that <code>url_id</code> associates with the user trough the</p> <pre><code>`urls` table (`id`, `user_id`) </code></pre> <p>The standalone query would look like this:</p> <pre><code>"SELECT `t1`.`data` FROM `tasks` `t1` JOIN `urls` `u1` ON `u1`.`id` = `t1`.`url_id` WHERE `u1`.user_id` = 1;" </code></pre> <p>Though, is it possible to merge these two queries into a single query? My logic says it should be, though I don't see how to do the actual JOIN.</p>
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    1. CODid you mean `data` or `date` in your last query? Also, if you are not selecting any data from the URL table, do you really need to join to it? (The answer could be "yes, to ensure that there is a URL entry for that user ID".) And why so many back-ticks; it is as bad as MS SQL Server and square brackets!
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    2. COI've written the query on the way, so I naturally left few mistakes. You are right though, it had to be `date` not `data`. I'd normally ignore a remark about `back-ticks`, though you have quite high reputation, so I am kinda curious why you are saying that "it is as bad as MS SQL Server and square brackets"? The purpose itself of backticks is to ensure that MySQL server is able to quickly identify table and column names and to avoid confusion when using reserved keywords, like `left` or `right` in nested sets.
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    3. COThe same claim is made for square brackets by MS SQL Server users. It looks ugly to me and it is wholly non-standard. No other DBMS supports back-ticks or square brackets for what the SQL standard calls 'delimited identifiers', which the standard says are enclosed in double quotes; single quotes are reserved for strings. Different DBMS have different rules for where you can use keywords. The one I use mostly allows keywords as identifiers in many places. It's best to avoid the quotes by avoiding keywords as identifiers.
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