获取计算列的distinct值 var distinctValues = dbContext.YourTable .Select(x => x.ComputedColumn) // 替换为计算列的名称 .Distinct(); // 遍历结果并输出 foreach (var value in distinctValues) { Console.WriteLine(value); }
INSERT INTO `table_a` VALUES ('1', 'a'); INSERT INTO `table_a` VALUES ('2', 'b'); INSERT INTO `table_a` VALUES ('3', 'c'); INSERT INTO `table_a` VALUES ('4', 'c'); INSERT INTO `table_a` VALUES ('5', 'b'); INSERT INTO `table_a` VALUES ('1', 'a'); 表ta...
create table t1(c1 number, c2 number not null); create table t2(c1 number, c2 number not null); insert into t1 values (1,1); insert into t1 values (1,2); insert into t1 values (2,2); insert into t2 values (1,2); commit; SQL> SQL> select /*+ place_distinct(t2) */ disti...
In this article Syntax Arguments Remarks Examples See Also Applies to: SQL Server Removes duplicate values from the sequence specified by $arg. If $arg is an empty sequence, the function returns the empty sequence. Syntax Copy fn:distinct-values($arg as xdt:anyAtomicType*) as xdt:...
在SQL查询器输入以下语句 create table test ( a varchar(20), b varchar(20), c varchar(20) ) insert into test values(1,'a','甲') insert into test values(1,'a','甲') insert into test values(1,'a','甲') insert into test values(1,'a','甲') ...
Here, the SQL command selects unique ages and orders them in descending order from theCustomerstable. To learn more, visitSQL ORDER BY. SELECT DISTINCT vs SELECT TheSELECT DISTINCTstatement is used when you want to return only unique (distinct) values in the result set. ...
(field1, field2) VALUES (1, 2)")cursor.execute("INSERT INTO mytable (field1, field2) VALUES (2, 3)")cursor.execute("INSERT INTO mytable (field1, field2) VALUES (1, 2)")cursor.execute("INSERT INTO mytable (field1, field2) VALUES (3, 4)")# 执行 SQL 查询语句cursor.execute(...
The SELECT DISTINCT command returns only distinct (different) values in the result set.The following SQL statement selects only the DISTINCT values from the "Country" column in the "Customers" table:ExampleGet your own SQL Server SELECT DISTINCT Country FROM Customers; Try it Yourself » ...
Learn how to use the distinct-values function in an XQuery to remove duplicate values from a sequence.
Null values are considered equal in this comparison. 2、返回指定列唯一的任意行。 也可以使用窗口来实现类似功能, 但是性能没有distinct on好,因为它是任意的。 Alternatively, an arbitrary expression can determine what rows are to be considered distinct: SELECT DISTINCT ON (expression [, expression .....