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MySQL: Invalid use of group function
I am using MySQL. Here is my schema:
2 Answers
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How to select records from last 24 hours using SQL?
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In MySQL:
SELECT *
FROM mytable
WHERE record_date >= NOW() - INTERVAL 1 DAY
In SQL Server:
SELECT *
FROM mytable
WHERE record_date >= DATEADD(day, -1, GETDATE())
In Oracle:
SELECT *
FROM mytable
WHER...
MySQL: Can't create table (errno: 150)
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From the MySQL - FOREIGN KEY Constraints Documentation:
If you re-create a table that was dropped, it must have a definition that conforms to the foreign key constraints referencing it. It must have the correct column names and ty...
How to change the default charset of a MySQL table?
There is a MySQL table which has this definition taken from SQLYog Enterprise :
5 Answers
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Is there a naming convention for MySQL?
...e your standard, then run with it.
To answer your question outright - no, MySQL doesn't have a preferred naming convention/standard, so rolling your own is fine (and yours seems logical).
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Troubleshooting “Illegal mix of collations” error in mysql
...g the below error when trying to do a select through a stored procedure in MySQL.
16 Answers
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How to add a primary key to a MySQL table?
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mysql doesn't recognize MODIFY as proper statement(at least in XAMPP, InnoDB)
– LMD
Jul 13 '18 at 18:25
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How do I convert from BLOB to TEXT in MySQL?
I have a whole lot of records where text has been stored in a blob in MySQL. For ease of handling I'd like to change the format in the database to TEXT... Any ideas how easily to make the change so as not to interrupt the data - I guess it will need to be encoded properly?
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Difference between Key, Primary Key, Unique Key and Index in MySQL
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KEY and INDEX are synonyms in MySQL. They mean the same thing. In databases you would use indexes to improve the speed of data retrieval. An index is typically created on columns used in JOIN, WHERE, and ORDER BY clauses.
Imagine you have a table called...
How to add not null constraint to existing column in MySQL
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Oddly I was getting an error (MySQL 5.6, Workbench 6.3) changing/modifying a column I'd named null_heart_rate_count, error was #1138, Invalid use of NULL value. I had to drop and add the column instead.
– William T. Mallard
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