Mysql numeric type conversion function _mysql

1, the int to varchar often use the concat function, such as concat (8, ' 0 ') to get the string ' 80 '
2. Convert varchar to int using CAST (a as signed) a as varchar type string
Summary: Type conversions, like SQL Server, are somewhat different from type parameters: CAST (xxx as type), convert (XXX, type)
Types that are available
Binary, with the effect of BINARY prefix: BINARY
Character type, with parameters: CHAR ()
Dates: Date
Time: Times
Date-time: DATETIME
Floating point numbers: DECIMAL
Integer: Signed
unsigned integer: UNSIGNED