SELECTDISTINCTcolumn_1FROMtable_name;Code language:SQL (Structured Query Language)(sql) In this statement, theDISTINCToperator compares values in thecolumn_1of thetableto determine the duplicates. To retrieve u
(1)DISTINCT语法结构 --SELECTDISTINCT列1,列2,列3...from 表名;select distinct stuaddress,grade from jalen.stuinfo;select distinct job from scott.emp; 1. 2. 3. ##(2)where的 =、IN、LIKE、BETWEEN...AND、AND、OR、NOT --where的=、IN、LIKE、BETWEEN...AND、AND、OR、NOTselect*from scott....
SELECT column1, column2 FROM table1 WHERE column3 IN (SELECT column4 FROM table2 WHERE column5 = table1.column6); 在上面的查询中,主查询从table1表中选择column1和column2列的数据。子查询从table2表中选择column4列的数据,并且根据table1的column6列与table2的column5列进行关联。只有满足关联条件的...
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 列的别名可以使...
语法结构:SQL>select distinct列名from表名; 例7:查询sc表中信息,去反复 解:首先查询sc表中全部数据 然后查询sc表的cno列数据 利用distinct去反复 七、WHERE子句使用 在SELECT语句中使用WHERE子句来过滤查询出来的结果。 语法格式: (1)where列名比較操作符数值; ...
You can specify multiple columns in a GROUP BY clause. For example, the following query includes the city and description columns from the employee table in a GROUP BY clause: SQL> -- create demo table SQL> create table Employee( 2 ID VARCHAR2(4 BYTE) NOT NULL, 3 First_Name VARCHAR2(...
EXTRACT Expression FILTER Clause FROM Clause Column Names IS DISTINCT FROM Predicate LISTAGG Function MATCH_RECOGNIZE Clause VALUES Clause WITH Clause Use Cases Drafting Queries Without Tables Literate SQL Naming unnamed columns Pivot Reduce INSERT latency SELECT without FROM Testing on Transient Data ...
4.开启任务: SQL>BEGIN2DBMS_SCHEDULER.ENABLE(3name=>'"SYS"."FRIDAY_WINDOW"');4END;5/ PL/SQL 过程已成功完成。5.查看修改后的情况: SQL>selectt1.window_name,t1.repeat_interval,t1.duration from dba_scheduler_windows t1,dba_scheduler_wingroup_members t22wheret1.window_name=t2.window_name ...
selecttestid,count(1)fromtesttablegroupbytestidhingcount(1)>1。 count(1)就是重复在数量。 二、Oracle查询表中字段里数据是否有重复 如果两列数据重复的话,可以通过count方法,找出计算条数大于1的,那么表示此条数据重复: sql: select district() from products hing count()>1; ...
SQL> select table_name,column_name,num_distinct,density from user_tab_columns where table_name = 'TEST'; TABLE_NAME COLUMN_NAME NUM_DISTINCT DENSITY --- --- --- --- TEST OWNER 25 .365014295 TEST OBJECT_NAME 30275 .000039205 TEST SUBOBJECT_NAME 191 .015657993 TEST OBJECT...