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Development Tools Database Foundations Joining Relational Data Between Tables in SQL Keys and Auto-Incrementing Values

Geoffrey Neal
Geoffrey Neal
30,298 Points
Posted by Geoffrey Neal
Geoffrey Neal
30,298 Points

PRIMARY KEY returning null.

So I've specified the AUTO_INCREMENT and PRIMARY KEY keywords for the id column, and generally speaking it works as expected. However, when the id column reaches 250 (i.e. the last row) it adds one more row to each column with a value of null. It's not a major inconvenience but I thought a PRIMARY KEY automatically stops this from happening, at least in the id column. This still happens when I specify NOT NULL, any ideas??

1 Answer

Andrew McCormick
Andrew McCormick
17,730 Points
Andrew McCormick
Andrew McCormick
17,730 Points

When you say "it adds" what is the 'it' that you are speaking of? The tool that you are using? If this is in your tool, then is it only when you add it, not before you save it? A lot of tools will fill in the values with null while you add the values. However is a column cannot be null and you save it as null then it should error out.