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Can we use integer in varchar?
VARCHAR (length) A VARCHAR declaration must include a positive integer in parentheses to define the maximum allowable character string length. If you need to store character strings that are longer than the current table page size, the Character Large Object (CLOB) data type should be used.
Is int faster than varchar?
Int comparisons are faster than varchar comparisons, for the simple fact that ints take up much less space than varchars. This holds true both for unindexed and indexed access. The fastest way to go is an indexed int column.
Can foreign key be VARCHAR?
I would say it is fine to use VARCHAR as both PRIMARY and FOREIGN KEYS. Only issue I could forsee is if you have a table, lets say Instruments (share instruments) and you create the PRIMARY/FOREIGN KEY as VARCHAR, and it happens that the CODE changes.
Can we make string as primary key?
The short answer : It’s perfectly fine to use a string as a primary key. What is a good primary key candidate ? It should be unique. It should rarely, if at all, change.
What is VARCHAR and int?
Integer is for numbers, and varchar is for numbers, letters and other characters (Short text). So for age you can use a int type, for genders you can use the enum() type if there are only two options. – Variable. May 8 ’17 at 9:34.
When to use varchar as a primary key?
I’d like to use VARCHAR as the primary key for reference lists (think US States, Country Codes) and a coworker won’t budge on the INT AUTO_INCREMENT as a primary key for all tables.
Which is worse A varchar or an int?
VARCHAR vs. INT doesn’t tell much. What matter is the access pattern. On absolute terms, a wider key will always be worse than a narrow key. The type carries absolutely no importance, is the width that matters.
Which is better an integer or an int?
When compared with INT though, few types can beat INT in narrowness, so INT usually wins that argument just by the fact that is only 4 bytes wide. But what really matters is the choice of clustered key. Often confused with the primary key, the two represent different notions and are not required to overlap.