If a default value evaluates to a data type that differs from the declared column type, implicit coercion to the declared type occurs according to the usual MySQL type-conversion rules. SeeSection 14.3, “Type Conversion in Expression Evaluation”....
If strict mode is not enabled, MySQL sets the column to the implicit default value for the column data type. In this case,ihas no explicit default, so in strict mode each of the following statements produce an error and no row is inserted. When not using strict mode, only the third st...
ENUM的字段值不区分大小写。如insert into tb1 values("M"); 和insert into tb1 values("m");效果一样的。 补充: enum的存储原理: (http://justwinit.cn/post/7354/?utm_source=tuicool&utm_medium=referral) 在建立enum类型的字段时,我们会给他规定一个范围比如 enum('a','b','c'),这时mysql内部...
TheTIMEdata type is used to display time in MySQL. It shows values inHH:MM:SSformat. MySQL retrieves and displaysTIMEvalues in 'HH:MM:SS' format or 'HHH:MM:SS' format for large hours values. The range is from-838:59:59to838:59:59. The hours part of the time format may be grea...
所以推荐使用文本型的varchar等非enum类型的,这样就OK了 问题现象来源: /var/www/apache2/error.log PHP Fatal error: Uncaught PDOException: SQLSTATE[01000]: Warning: 1265 Data truncated for column'user_reg_ip' at row 1 in /var/www/w/wxApi/vendor/phalapi/notorm/src/NotORM/Result.php:271\nSt...
ENUM(val1, val2, val3, ...)A string object that can have only one value, chosen from a list of possible values. You can list up to 65535 values in an ENUM list. If a value is inserted that is not in the list, a blank value will be inserted. The values are sorted in the or...
Booleans can be stored as TINYINTs (0=false, nonzero=true) or ENUM('False',True') -- I prefer the TINYINT option personally. Hash values, depends on how many bits and how represented. A numeric type like INT or BIGINT, a BINARY type (fixed length binary) or a CHAR type (...
`type` enum('BASE TABLE','VIEW','SYSTEM VIEW') COLLATE utf8_bin NOT NULL, `engine` varchar(64) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL, `mysql_version_id` int(10) unsigned NOT NULL, `row_format` enum('Fixed','Dynamic','Compressed','Redundant','Compact','Paged') COL...
mysql新建data文件夹 mysql怎么创建文件 这一部分主要使用SQL中的DDL,数据库定义语言(data definition language),对数据库,表进行新建,修改,和删除。 数据库(database) 显示所有数据库 SHOW DATABASES; 1. 创建数据库 CREATE DATABASE db_name; 1. 每创建一个数据库,就会在Data目录下新建一个以数据库名字命名(...
--flush-privileges 备份mysql或相关时需要使用 -f, --force 忽略SQL错误,继续执行 --hex-blob 使用十六进制符号转储二进制列,当有包括BINARY,VARBINARY,BLOB,BIT的数据类型的列时使用,避免乱码 -q, --quick 不缓存查询,直接输出,加快备份速度 mysqldump实验部分 单个数据库的备份...