百度试题 题目SQL 语句可返回唯一不同的值的是( )。 A. SELECT ALL B. SELECT DIFFERENT C. SELECT UNIQUE D. SELECT DISTINCT 相关知识点: 试题来源: 解析 D null 反馈 收藏
SQL提供SELECT语句的嵌套子查询机制。子查询是嵌套在另一个查询中的SELECT语句。 (1)集合成员资格的比较 元组 [NOT] IN (集合) 例 检索至少不学C2和C4两门课程的学生学号。 SELECT S# FROM S WHERE S# NOT IN(SELECT S# FROM SC WHERE C# IN ('C2','C4')); (2)集合成员的算术比较 元组θSOME[ALL...
If the data is expected to have duplicate results, use DISTINCT keyword to eliminate duplicates and diplay only the unique results in the query output. Only the selected columns are validated for duplication and the rows will be logically eliminated from the query output. To be noted, the DISTI...
SQL SELECT is probably the most widely used SQL statement. That's why we have decided to investigate options that can be used in the query.
The SELECT statement retrieves rows from the database and enables the selection of rows or columns from tables in the SQL Server Database Engine.
The SELECT statement in SQL is used to retrieve data from a relational database. SyntaxNumber of ColumnsSQL Syntax 1 SELECT "column_name" FROM "table_name"; More Than 1 SELECT "column_name1"[, "column_name2"] FROM "table_name"; All SELECT * FROM "table_name";"...
aspartitionorderbyupdate_date)asupdate_date,last_value(sq_nbr)over(partitionbyid,addr,indorderby statement. Example ishere a.*orginoneper
SETodps.sql.allow.fullscan=true;SELECT*fromsale_detail; If you want to query clustered tables, you can execute a SELECT statement to perform bucket pruning only when the number of partitions that can be scanned in a single table is less than or equal to 400. If bucket pruning does not ...
Microsoft.Data.Schema.ScriptDom.Sql 命名空间 AddAlterFullTextIndexAction 类 AddFileSpec 类 AddSignatureStatement 类 AdhocDataSource 类 AdhocTableSource 类 AffinityKind 枚举 AlgorithmKeyOption 类 AlterAction 枚举 AlterApplicationRoleStatement 类
If it is important to ensure the same row order with and without LIMIT, include additional columns in the ORDER BY clause to make the order deterministic. For example, if id values are unique, you can make rows for a given category value appear in id order by sorting like this: ...