# Summary Of Implicit Data Type Conversions


![left](./student-guide/diagram/01-17-1.png)

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The implicit conversion rules of TiDB are consistent with MySQL. Let's summarize the common implicit conversion rules for operations (here are common equivalence comparisons, join):

- If one of the parameter is a number and the other is a string, the string will be converted to a number.
- If one of the parameter is a TIMESTAMP or DATETIME column and the other parameter is a constant, the constant will be converted to a timestamp.
- If one of the parameter is a decimal value, the comparison depends on the other. If the other parameter is a decimal or integer value, the parameter is compared as a decimal value, and as a floating point value if the other parameter is a floating-point value.

Here are just some common rules, please check the MySQL official website for more detailed rules. It is strongly recommended that you use the same type for operations and retrieving data to avoid performance issues caused by implicit conversions.