The storage requirements for table data on disk depend on several factors. Different storage engines represent【ˌreprɪˈzent代表,表示;(在竞赛或体育赛事中)代表(国家或地区);(标志或符号)意味着,代表着,标志着;描绘,(形象地)表现,描写;代理(个人或团体);代表(个人或团体)出席;】 data types and ...
13.6 Data Type Default Values Data type specifications can have explicit or implicit default values. ADEFAULTvalueclause in a data type specification explicitly indicates a default value for a column. Examples: CREATETABLEt1(iINTDEFAULT-1,cVARCHAR(10)DEFAULT'',priceDOUBLE(16,2)DEFAULT0.00); ...
As of MySQL 8.0.19, theYEAR(4)data type with an explicit display width is deprecated; you should expect support for it to be removed in a future version of MySQL. Instead, useYEARwithout a display width, which has the same meaning. ...
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For complete information regarding syntax and additional examples, see the description of theCAST()function. 有关语法和其他示例的完整信息,请参阅CAST()函数的说明。 Be aware of certain properties of date value interpretation in MySQL: 注意MySQL 中日期值解释的某些属性: ...
In MySQL 8.0.19 and later, you can specify a time zone offset when inserting aTIMESTAMPorDATETIMEvalue into a table. SeeSection 9.1.3, “Date and Time Literals”[8], for more information and examples. 在MySQL 8.0.19 及更高版本中,在表中插入TIMESTAMP或DATETIME值时,可以指定时区偏移。更多信...
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In MySQL 8.0.19 and later, you can specify a time zoneoffsetwhen inserting aTIMESTAMPorDATETIMEvalue into a table. SeeSection 9.1.3, “Date and Time Literals”[8], for more information and examples. 在MySQL 8.0.19 及更高版本中,在表中插入TIMESTAMP或DATETIME值时,可以指定时区偏移。更多信息和...
• Be careful with ENUM and SET . They’re handy, but they can be abused, and they’re tricky sometimes. BIT is best avoided. Normalization is good, but denormalization (duplication of data, in most cases) is sometimes actually necessary and beneficial. We’ll see more examples of that...
- Columns with data types which are not safe to be stored in text form (i.e. BLOB) are converted to Base64, hence the size of such columns cannot exceed approximately 0.74 * max_allowed_packet bytes, as configured through that system variable at the target server. - Schema object names...