SQL语句大全 –语 句功能 –数据操作 SELECT –从数据库表中检索数据行和列 INSERT –向数据库表添加新数据行 DELETE –从数据库表中删除数据行 UPDATE –更新数据库表中的数据 -数据定义 CREATE TABLE –创建一个数据库表 DROP TABLE –从数据库中删除表 ALTER TABLE –修改数据库表结
• int | integer：常用整数类型，占位4Bytes，取值范围-2147483548~2147483647。• bigint：超大整数类型，占位8Bytes，取值范围-9223372036854775808~9223372036854775807。• float：单精度浮点数类型，占位4Bytes，取值范围-3.4E+38 ~ 3.4E+38。• double：双精度浮点数类型，占位8Bytes，取值范围-1.7E-308～...
重启数据库 SQL>shutdownimmediate;Databaseclosed.Databasedismounted.ORACLEinstanceshutdown.SQL>startupORACLEinstancestarted.TotalSystemGlobalArea2432695144bytesFixedSize8899432bytesVariableSize536870912bytesDatabaseBuffers1879048192bytesRedoBuffers7876608bytesDatabasemounted.Databaseopened.SQL>showparameteraudit_trail;NAME...
SPACE(integer_expression):返回一个由参数integer_expression所指定长度的空格字符串。若参数为负值,则返回NULL串 STUFF(character_expression1, start_position, length, character_expression2):用另一个子串替换字符串中指定位置长度的子串。1为源串,start为替换的起始位置,length为被替换的字符串长度,2为目标字符串...
This function adds anumber(a signed integer) to adatepartof an inputdate, and returns a modified date/time value. For example, you can use this function to find the date that is 7,000 minutes from today:number= 7000,datepart= minute,date= today. ...
The banker’s rounding rule is widely regarded as yielding the most valid conversion of a decimal value to an integer value. For example, Peter Deegan, in a blog titledWhy Excel’s Round() function is wrong, presents empirical evidence confirming that the banker’s rounding is more accurate ...
int(expr) Casts the value expr to INTEGER. isnan(expr) Returns true if expr is NaN. ln(expr) Returns the natural logarithm (base e) of expr. log([base,] expr) Returns the logarithm of expr with base. log1p(expr) Returns log(1 + expr). log2(expr) Returns the logarithm ...
You must then manually shut down the database before you can reopen it. GROUP Clause Specify GROUP to manually archive the online redo log file group with the GROUP value specified by integer. You can determine the GROUP value for a redo log file group by querying the data dictionary ...
Connection public interface Connection extends Wrapper, AutoCloseable A connection (session) wi……欲了解更多信息欢迎访问华为HarmonyOS开发者官网