Expression
- Except for special processing, expressions containing null are always null.
Operator
- {And | &}, {or | |}, {XOR} {not | !}
- [Not] between... and...
- &,~ , |, ^: (BIT) And, reverse, or, different or
- Case: ANSI standard operator
- Is [not] {null | true | false}
- =, >=,>, <=, <, <=> ,! =, <> -- "<=>" Secure equals: The expression "null <=> null" is true1. If one of them is null, false0 is returned.
- +,-, *,/, %, Div -- Div (floor () is used for integer division, which is safe for bigint; % (mod () is used for remainder.
- [Not] Like
- [Not] {rlike | Regexp} -- Regular Expression Pattern Matching
- >>,<<-- Shifts right and left
- Binary -- Keyword: Forced String Conversion to binary mode
- () -- Change the operator priority.
- Special operation functions
In (), least (), greatest (), coalesce (), interval (), isnull (), strcmp ()...
If () is similar to C? Ternary operators, ifnull () are similar to SQL Server's isnull (), nullif (),
Type conversion
- When either side of the comparison is datetime or timestamp, and the other side is a constant, the constant is implicitly converted to datetime or timestamp.
- The two types are the same and compared according to the same type
- In other cases, convert to Duble-you may not need to go to the highest level, but the level of tolerance in the middle.
- Implicit conversion:
- Display conversion: Cast (), convert (), and binary. Note that the cast function supports the following types: binary (M), char (M), date, datetime, singed, unsigned, decimal (M, D)
Special Functions
- Benchmark () Repeated execution expression
- Default () gets the default value of the table column
- Last_day () the last date of a month
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