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How do I get SUM function in MySQL to return '0' if no values are found?
Say I have a simple function in MySQL:
4 Answers
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Calculate difference between two datetimes in MySQL
I am storing the last login time in MySQL in, datetime -type filed. When users logs in, I want to get the difference between the last login time and the current time (which I get using NOW() ).
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Compare dates in MySQL
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For people comming from google: date type in mysql comes in yyyy-mm-dd format.
– Błażej Michalik
Nov 29 '15 at 20:24
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Simulating group_concat MySQL function in Microsoft SQL Server 2005?
I'm trying to migrate a MySQL-based app over to Microsoft SQL Server 2005 (not by choice, but that's life).
11 Answers
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MySQL remove all whitespaces from the entire column
...UPDATE `table` SET `col_name` = REPLACE(`col_name`, '\n', '')
http://dev.mysql.com/doc/refman/5.0/en/string-functions.html#function_replace
To remove first and last space(s) of column :
UPDATE `table` SET `col_name` = TRIM(`col_name`)
http://dev.mysql.com/doc/refman/5.0/en/string-functions.htm...
Convert text into number in MySQL query
Is it possible to convert text into number within MySQL query? I have a column with an identifier that consists a name and a number in the format of "name-number". The column has VARCHAR type. I want to sort the rows according the number (rows with the same name) but the column is sorted according d...
Ordering by specific field value first
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There's also the MySQL FIELD function.
If you want complete sorting for all possible values:
SELECT id, name, priority
FROM mytable
ORDER BY FIELD(name, "core", "board", "other")
If you only care that "core" is first and the other values ...
How to get current date & time in MySQL?
...ment:
Core i3 Windows Laptop with 4GB RAM, and I did the above example on MySQL Workbench 6.2 (Version 6.2.5.0 Build 397 64 Bits)
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How to change collation of database, table, column?
...ame != 'utf8_general_ci' AND table_schema not in ('information_schema','mysql', 'performance_schema','sys');
– William Entriken
Dec 12 '19 at 19:56
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Which is faster: multiple single INSERTs or one multiple-row INSERT?
I am trying to optimize one part of my code that inserts data into MySQL. Should I chain INSERTs to make one huge multiple-row INSERT or are multiple separate INSERTs faster?
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