Shulou(Shulou.com)06/01 Report--

What the editor wants to share with you this time is to talk about the data types and operation datasheets in MYSQL. The article is rich in content, and interested friends can learn about it. I hope you can get something after reading this article.

Data type and operation data sheet

1.1 Integer of MySQL type

1.2 floating point type of MySQL data type

1.3 date and time type

DATE 1 support time: January 1, 1000 to December 31, 9999

DATETIME 3 support time: 00: 00 seconds on January 1, 1000 to 23:59:59 on December 31, 9999

TIMESTAMP 3 support time: January 1, 1970 to December 31, 2037

TIME 8 support time:-838595908385959

YEAR 4 support time: 1970-2069

1.4 character type

CHAR: fixed length. If insufficient, fill in the blanks.

VARCHAR: variable length (variable: variable)

The extra bytes in Loby1 or Law2 are used to hold the length of the data value. When dealing with variable-length data, MySQL saves both the content and the length of the data.

1 refers to the maximum storage range of L, and 1 byte is 8 1s.

The highest bit for signed numbers is symbolic bits, but the character type is unsigned, so 2 ^ 7 + 2 ^ 6 + 2 ^ 5 + 2 ^ 4 + 2 ^ 3 + 2 ^ 2 + 2 ^ 1 + 1 "255, that is, the first L

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