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Insert into a MySQL table or update if exists

... Use INSERT ... ON DUPLICATE KEY UPDATE QUERY: INSERT INTO table (id, name, age) VALUES(1, "A", 19) ON DUPLICATE KEY UPDATE name="A", age=19 share | improve this answer | ...
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How do I get the YouTube video ID from a URL?

I want to get the v=id from YouTube’s URL with JavaScript (no jQuery, pure JavaScript). 39 Answers ...
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How to debug Lock wait timeout exceeded on MySQL?

... What gives this away is the word transaction. It is evident by the statement that the query was attempting to change at least one row in one or more InnoDB tables. Since you know the query, all the tables being accessed are candidates for being the culprit. From there, you shou...
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How do I select an entire row which has the largest ID in the table?

... You could use a subselect: SELECT row FROM table WHERE id=( SELECT max(id) FROM table ) Note that if the value of max(id) is not unique, multiple rows are returned. If you only want one such row, use @MichaelMior's answer, SELECT row from table ORDER BY id DESC LIMIT...
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SQL RANK() versus ROW_NUMBER()

...bout the differences between these. Running the following SQL gets me two idential result sets. Can someone please explain the differences? ...
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jQuery Determine if a matched class has a given id

What is jQuery has id equivalent of the following statement? 8 Answers 8 ...
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How to count occurrences of a column value efficiently in SQL?

... SELECT age, count(age) FROM Students GROUP by age If you need the id as well you could include the above as a sub query like so: SELECT S.id, S.age, C.cnt FROM Students S INNER JOIN (SELECT age, count(age) as cnt FROM Students GROUP BY ag...
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SQL join: selecting the last records in a one-to-many relationship

...mmend solving it: SELECT c.*, p1.* FROM customer c JOIN purchase p1 ON (c.id = p1.customer_id) LEFT OUTER JOIN purchase p2 ON (c.id = p2.customer_id AND (p1.date < p2.date OR (p1.date = p2.date AND p1.id < p2.id))) WHERE p2.id IS NULL; Explanation: given a row p1, there should be no ro...
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How to annotate MYSQL autoincrement field with JPA annotations

... To use a MySQL AUTO_INCREMENT column, you are supposed to use an IDENTITY strategy: @Id @GeneratedValue(strategy=GenerationType.IDENTITY) private Long id; Which is what you'd get when using AUTO with MySQL: @Id @GeneratedValue(strategy=GenerationType.AUTO) private Long id; Which is a...
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MySQL Multiple Joins in one query?

... dashboard_data.headline, dashboard_data.message, dashboard_messages.image_id, images.filename FROM dashboard_data INNER JOIN dashboard_messages ON dashboard_message_id = dashboard_messages.id INNER JOIN images ON dashboard_messages.image_id = images.image_id However be ...