In your query, 2010-4-01 is treated as a mathematical expression, so in essence it read (2010 minus 4 minus 1 is 2005 Converting it to a proper datetime, and using single quotes will fix this issue.) Technically, the parser might allow you to get away with it will do the conversion for you, but in my opinion it is … Read more
Use INSERT … SELECT: where c1, c2, … are all the columns except id. If you want to explicitly insert with an id of 2 then include that in your INSERT column list and your SELECT: You’ll have to take care of a possible duplicate id of 2 in the second case of course.
You can see the output for this request HERE
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 types, and it must have indexes on the referenced keys, as stated earlier. If these are not satisfied, MySQL … Read more
Here’s a UDF that will do the trick… You will still have to use it to update your data though.
Such unexpected problems can appear when you copy the code from a web page or email and the text contains unprintable characters like individual CR or LF and non-breaking spaces.
Use a JOIN in the DELETE statement. Alternatively you can use… …to delete only from pets_activities See this. For single table deletes, yet with referential integrity, there are other ways of doing with EXISTS, NOT EXISTS, IN, NOT IN and etc. But the one above where you specify from which tables to delete with an … Read more
Dynamic SQL PIVOT: Results:
This feature has been implemented in Postgres 9.1: For older versions, here is a function to work around it: Call: Notes The columns schemaname and tablename in pg_tables are case-sensitive. If you double-quote identifiers in the CREATE TABLE statement, you need to use the exact same spelling. If you don’t, you need to use lower-case strings. See: Are PostgreSQL column names case-sensitive? pg_tables only contains actual tables. The … Read more
When you want to replace a possibly null column with something else, use IsNull. This will put a 0 in myColumn if it is null in the first place.