backticks (`) are used for identifiers, like table names, column names, etc. Single quotes(‘) are used for string literals. You want to do: Or, to be more explicit: When there is no chance of ambiguity, and when table/column names do not have special characters or spaces, then you can leave the ` off. Here is … Read more
Constraints are part of a database schema definition. A constraint is usually associated with a table and is created with a CREATE CONSTRAINT or CREATE ASSERTION SQL statement. They define certain properties that data in a database must comply with. They can apply to a column, a whole table, more than one table or an entire schema. A reliable … Read more
Take a look at this. Change your query to: The last select is your count.
In my case, it was my SQL Server instance that was not running. I simply started the service and everything worked fine. Hope this helps someone down the road.
Cast/Convert the values to a Date type for your group by.
I know this is an old question. The way I solved it – after failing by increasing the length or even changing to data type text – was creating an XLSX file and importing. It accurately detected the data type instead of setting all columns as varchar(50). Turns out nvarchar(255) for that column would have … Read more
Without an index, maintaining an autoincrement column becomes too expensive, that’s why MySQL requires an autoincrement column to be a leftmost part of an index. You should remove the autoincrement property before dropping the key: Note that you have a composite PRIMARY KEY which covers all three columns and id is not guaranteed to be … Read more
This is an Array Formula. After entering the formula, press CTRL + Shift + Enter to have Excel evaluate it as an Array Formula. This returns the first nonblank value of the given range of cells. For your example, the formula is entered in the column with the header “a”
As far as I can tell, both syntaxes are equivalent. The first is SQL standard, the second is MySQL’s extension. So they should be exactly equivalent performance wise. http://dev.mysql.com/doc/refman/5.6/en/insert.html says: INSERT inserts new rows into an existing table. The INSERT … VALUES and INSERT … SET forms of the statement insert rows based on explicitly … Read more
Distinct and Group By are going to give you different results. To get the results you expect you’ll want to use Seen above, group will return things as a hash. While distinct just returns the number of people in total, seen below.