This is the basic syntax for using the DELETE query: DELETE FROM table_name In this article, we learned about the different ways to delete information from a SQL table. In order to delete all of the cats from our cats table, then we would use this code. If you want to delete all of the information from your table, then you would use this syntax: DELETE FROM table_name
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How to delete all records in the table in SQL Our DELETE query was successful, because those four cats are no longer present in the table. This is what the new result would look like: WHERE name IN ("Lucy","Stella","Max","Tiger") We need to specify the column and use the IN operator to list the names we want deleted. In this example, I want to delete the names of Lucy, Stella, Max and Tiger from our original cats table here: We can specify which names to delete from the cats table using the IN operator. How to delete multiple rows using the IN operator in SQL The ids of 4-7 have been successfully deleted. We can see that rows 1-3 and 8-10 are left in our table. This is the result from that DELETE query: Here is the syntax for that: DELETE FROM cats In this example, we want to delete rows with ids of 4-7 inclusive. If we wanted to delete a number of rows within a range, we can use the AND operator with the BETWEEN operator. How to delete multiple rows using the BETWEEN operator with the AND operator in SQL Now the cats table is only showing the female cats. If we wanted to delete the rows with just the male cats, then we can use the gender="M" condition. One way we can delete multiple rows from our cats table is to change the condition from id to gender. How to Delete multiple rows from a table in SQL We can see that our DELETE query worked because Loki's information is no longer there. This is what the new cats table looks like: Here is the complete syntax to delete Loki's row: DELETE FROM cats In the second line, we are going to specify which row by using the id=8 after the WHERE clause. The first line of the DELETE query would look like this: DELETE FROM cats We want to delete the row with the id of 8 which is Loki's row. The columns would be id, name and gender. In this example, we have a table called cats that currently has ten rows in it. WHERE condition of which row(s) to delete This is the basic syntax for using the the DELETE query: DELETE FROM table_name
I will also show you how to delete multiple rows from a table at once. In the article, I will walk you through how to use the DELETE query and WHERE clause to delete rows. The only complication with this is that it will not use any index on subject field because your use this function on it.In SQL, you can delete a row in a table by using the DELETE query and the WHERE clause. I've simulate your data example: mysql> SELECT * FROM `mail` I tested your function and it worked: mysql> SELECT removeExtraChar('abc - 123')
WHERE `subject` = removeExtraChar('abc - 123') If you used the function in the field subject if isnt indexed, this could take hours depending the amount of rows. I think that is your query the problem here. Note: I don't want to use extra mysql plugin. SELECT `id`,`user_id`,`subject` FROM `mail` where removeExtraChar(`subject`)=$subjectīut this goes in infinite loop. I tried with function CREATE FUNCTION `removeExtraChar`(`str` VARCHAR(255)) RETURNS varchar(255) CHARSET latin1 I know what i write above is not available.
want to compare like following SELECT `id`,`user_id`,`subject` FROM `mail` where preg_replace('//', '',`subject`)=$subject Is it possible to use preg_replace in my mysql query? What i get value in php $subject = preg_replace('//', '', 'abc - 123')
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