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Should a table always have a primary key?
Every table can have (but does not have to have) a primary key. The column or columns defined as the primary key ensure uniqueness in the table; no two rows can have the same key.
Should every table have an id column?
Every table (except for the rare conditions) should have a PRIMARY KEY , that is a value or a set of values that uniquely identify a row. See here for discussion why. IDENTITY is a property of a column in SQL Server which means that the column will be filled automatically with incrementing values.
Can a log table get a primary key?
If you don’t have joins on this table, no updates and no deletions, then you don’t need keys at all. If this is not the case, and messageId is unique, then you can make it a primary key. If it’s not unique, but (messageId, exportedDateTime) is, then make this a composite primary key.
Do you need a primary key ID table?
In my latest project I have the “ID” column set as my primary key, however I never call it or use it in any way, as the data in the row makes it unique and is much more useful for me. So, if every row in a SQL table is unique, does it need a primary key ID table, and are there ant performance changes with or without one? Thanks!
What does the ID field on a log table do?
I have a log table that captures the datetime stamp of when certain files were exported to another system. The exportedLog table currently has three fields: Reviewing this I found that the id field serves no purpose, as there are no joins to this table.
Is the ID column a primary key in SQL?
If you are sure that any other column is going to have unique data for every row and isn’t going to have NULL at any time then there is no need of separate ID column to distinguish each row from others, you can make that existing column primary key for your table. No, single-attribute keys are not essential and nor are surrogate keys.