-- The Distinct keyword must only be used before the first column in the query SELECTStudentId,Distinct(Name)FROMdbo.Student Common use cases Let us now discuss the common use cases of SQL SELECT Distinct statement. Analyzing and Improving data accuracy based on distinct values ...
Select –We can select the data as per the condition which was given in the query. This is the SQL statement that was used to select the specified data from a table. We can use select with a distinct count statements to retrieve unique count from the column. Name of column –This is ...
EXPLAIN SELECT DISTINCT a.col1 FROM tab1 a INNER JOIN tab2 b ON a.col1 = b.col1 WHERE b.col2 in ('value1', 'value2') ORDER BY a.col1 ; +---+---+---+---+---+---+---+---+---+---+ | id | select_type | table | type | possible_keys | key | key_len |...
Select DISTINCT name_of_column1, name_of_column2, …., name_of_columnN from name_of_table where condition order by name_of_column; Below is the description syntax of SQL select distinct multiple columns statement: Select:Using select, we can select the data as per the condition given in ...
SQL students also learn The SQL SELECT DISTINCT Statement The DISTINCT clause is used in a SELECT statement to remove duplicates from the result set of the query. Here is the syntax for this statement: SELECT DISTINCT expressions FROM tables WHERE conditions; ...
mysql变量In_useMySQL变量的分类 用户自定义变量局部变量会话变量@系统变量@@会话变量全局变量局部变量一般用于SQL的语句块中,比如存储过程中的begin和end语句块。其作用域仅限于该语句块内。生命周期也仅限于该存储过程的调用期间。drop procedure if exists add; create procedure add ( in a int, in b int )...
If the length of the description is less than 60, then display the description. Otherwise, check if the length of the product_name is less than 20. If it is, we display the product_name. Otherwise, display product. SELECT DISTINCT product_name, description, COALESCE( CASE WHEN LENGTH(descr...
I wonder if its possible to perform a ORDER BY clause in an SELECT DISTINCT sql query whereby the AS SINGLECOLUMN is used. At present I am recieving error: ORDER BY items must appear in the select list if SELECT DISTINCT is specified. My guess is that I cant perform the Order By ...
SQL 语法面试备忘录,建议收藏! ); GROUP BY 经常与聚合函数(COUNT、MAX、MIN、SUM、AVG)一起使用的语句,用于按一列或多列对结果集进行分组 SELECT column_name1, COUNT(column_name2...; DELETE * FROM table_name; 报告查询 COUNT 返回出现次数 SELECT COUNT (DISTINCT column_name); MIN() 和 M...
delete distinct () ... is not supported in Sql server. Wednesday, February 20, 2013 12:28 AM I tryed this : delete from employee where Name in (select distinct(Name) from employee) but it delete all the records delete from employee where Name NOT in (select distinct(Name) from ...