SELECTDISTINCTstateFROMlocationsORDERBYstateNULLSFIRST;Code language:SQL (Structured Query Language)(sql) Try it Result: The result set includes only oneNULL. Note that if you want to apply theDISTINCTto some columns, while skipping other columns, you should use theGROUP BYclause instead. Summary# Use theSELECT DISTINCToperator to get unique values based...
使用select语句仅输出nvarchar列中的某些值 Select distinct on值必须出现在group by中 选择distinct值pandas中的groupby列 如何从多个列的SELECT DISTINCT中删除重复项? 隐藏Oracle的select查询中的列 在Oracle中按一列选择distinct,但也显示多列 Distinct值,尽管case表达式中的列创建了非distinct值 ...
select * from表名[where条件] [group by分组列名] [having聚合函数] [order by排序列名ASC| DESC] 在表名地方,能够写多个表 2.查询指定表的部分列: select {[distinct]列名。列名,…}from表名[where条件] [group by分组列名] [having聚合函数] [order by排序列名ASC| DESC] 当中keyworddistinct表示去除部分...
SELECT DISTINCT name, age:去掉name字段重复的(需要先写去重的字段);如果想多个取出多个字段重复,需要用group by。
问Select语句ORACLE-SQL上的Distinct记录EN1. 列的别名 as:全称：alias(别名),可以省略 列的别名可以...
select distinct into #Tmp from tableName drop table tableName select into tableName from #Tmp drop table #Tmp 发生这种重复的原因是表设计不周产生的,增加唯一索引列即可解决。 2.这类重复问题通常要求保留重复记录中的第一条记录,操作方法如下
If either or both of the queries select values of datatypeVARCHAR2, then the returned values have datatypeVARCHAR2. Restrictions on Set Operators The set operators are not valid on columns of typeBLOB,CLOB,BFILE,VARRAY, or nested table. ...
It is distinct from the database area, which is a location for the current database files (data files, control files, and online redo log files). When creating your database, you can select the following options: ■ Specify Fast Recovery Area—Select this option to specify a backup and ...
Instead of citext you can also set a collation name that will be used in the columns definitions. To disable case insensitive search set it to: none. SELECT_TOP Append a TOP N clause to the SELECT command used to extract the data from SQL Server. This is the equivalent to a WHERE ...
s Number of LOB columns per table: An Oracle8, Oracle8i, or Oracle9i table can have multiple LOB columns. Each LOB column in the same table can be of a different type. In Oracle7 Release 7.3 and higher, tables are limited to a single LONG or LONG RAW column. s Random piece-wise ...