TheGROUP BYstatement groups rows that have the same values into summary rows, like "find the number of customers in each country". TheGROUP BYstatement is often used with aggregate functions (COUNT(),MAX(),MIN(),SUM(),AVG()) to group the result-set by one or more columns. ...
These are examples of syntactically valid SELECT statements: Syntax SELECT EmployeeName, EmployeeAddress FROM EmployeeDetails GROUP BY EmployeeName, EmployeeAddress; SELECT EmpName FROM EmployeeDetail GROUP BY EmpName, EmpAddress; SQL Copy Example SELECT GROUP BY with multiple GROUP BY expressions ...
Primary key: a field in a table which uniquely identifies each row/record in a database table. Primary keys must contain unique values. A primary key columncannot have NULLvalues.A table can have only one primary key, which may consist of single or multiple fields. Surrogate key: A surroga...
SELECT Country, Region, SUM(Sales) AS TotalSales FROM Sales GROUP BY GROUPING SETS ( ROLLUP (Country, Region), CUBE (Country, Region) ); The results are the same as this query that returns a union of the two GROUP BY statements. SQL Copy SELECT Country, Region, SUM(Sales) AS Total...
It’s usually listed as one of the last rows in a query, after any joins or where statements; typically you’ll only seeHAVING,ORDER BY, orLIMITstatements following it in a query You can group by multiple fields (ex.group by 1,2,3) if you need to; in general, we recommend performi...
You just have extra columns in SELECT and GROUP BY that you don't need
SQL_CU_DML_STATEMENTS = 所有数据操作语言语句都支持目录:SELECT、INSERT、UPDATE、DELETE;如果受支持,则SELECT FOR UPDATE 和定位更新和删除语句。SQL_CU_PROCEDURE_INVOCATION = ODBC 过程调用语句支持目录。SQL_CU_TABLE_DEFINITION = 所有表定义语句都支持目录:CREATE TABLE、CREATE VIEW、ALTER TABLE、DROP TABLE ...
You just have extra columns in SELECT and GROUP BY that you don't need
Specifies multiple groupings of data in one query. Only the specified groups are aggregated instead of the full set of aggregations that are generated by CUBE or ROLLUP. The results are the equivalent of UNION ALL of the specified groups. GROUPING SETS can contain a single element or a list...
A common table expression (CTE) is a named temporary result set that exists within the scope of a single statement and that can be referred to later within that statement, possibly multiple times. The following discussion describes how to write statements that use CTEs....