1、 Distinct 位置 单独的distinct只能放在开头,否则报错,语法错误 例:SELECT Sid,DISTINCT(Sscore) score from t_student; [SQL]SELECT Sid,DISTINCT(Sscore) score from t_student; [Err] 1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version fo...
-- 会提示错误,因为distinct必须放在开头 /*[SQL]SELECT id, DISTINCT NAME FROM table_a; [Err] 1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'DISTINCT NAME FROM table_a' at line 3 */ 5.其...
This SQL tutorial explains how to use the SQL DISTINCT clause with syntax and examples. The SQL DISTINCT clause is used to remove duplicates from the result set of a SELECT statement.
SyntaxMásolás Distinct(Set_Expression) ArgumentsSet_Expression A valid Multidimensional Expressions (MDX) expression that returns a set.RemarksIf the Distinct function finds duplicate tuples in the specified set, the function keeps only the first instance of the duplicate tuple while leaving the ...
SQL 错误 [1064] [42000]: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'distinct code from tt' at line 1 但是如上SQL使用distinct关键字,并没有满足需求,即得到code的唯一值,但同时带着cdate和ctotal两...
使用Distinct和Count的SQL查询 可以用于对数据库中的数据进行去重和统计操作。 Distinct是用于查询结果去重的关键词,它能够消除查询结果中的重复行,保留唯一的数据行。例如,可以使用以下语句查询表中不重复的城市名称: 代码语言:txt 复制 SELECT DISTINCT city FROM table_name; Count是用于统计查询结果数量的聚合函数,它...
Syntax Distinct(Set_Expression) Arguments Set_Expression A valid Multidimensional Expressions (MDX) expression that returns a set. Remarks If the Distinct function finds duplicate tuples in the specified set, the function keeps only the first instance of the duplicate tuple while leaving the order of...
If you omit theDISTINCTkeyword, the SQL statement returns the "Country" value from all the records of the "Customers" table: Example SELECTCountryFROMCustomers; Try it Yourself » Count Distinct By using theDISTINCTkeyword in a function calledCOUNT, we can return the number of different countri...
So, is SQL DISTINCT good or bad in removing duplicates in results? The results say that it’s good. It’s not better or worse than GROUP BY because the plans are the same. But it’s a good habit to check the execution plan. Think ofoptimizationfrom the start. That way, if you stu...
"Given an internal table, create an internal table containing all the distinct values that appear in a certain column" So this really is something very simple, similar to a SELECT DISTINCT in SQL. In a good programming language, a simple task must have a simple solution. So let's try....