代码语言:sql 复制 SELECT * FROM Customers FETCH FIRST 3 ROWS ONLY; 使用旧版 Oracle 的 ROWNUM 以下SQL 语句展示了旧版 Oracle 的等效示例: 选择"Customers" 表的前 3 条记录: 代码语言:sql 复制 SELECT * FROM Customers WHERE ROWNUM <= 3; 添加WHERE 子句 以下SQL 语句从 "Customers" 表中选择前三...
FETCHFIRST3ROWSONLY; 使用旧版 Oracle 的 ROWNUM 以下SQL 语句展示了旧版 Oracle 的等效示例: 选择"Customers" 表的前 3 条记录: SELECT*FROMCustomers WHEREROWNUM<=3; 添加WHERE 子句 以下SQL 语句从 "Customers" 表中选择前三条记录,其中国家是 "Germany"(对于 SQL Server/MS Access): SELECTTOP3*FROMCus...
SQL DELETEProduction.ProductCostHistoryWHEREStandardCostBETWEEN12.00AND14.00ANDEndDateISNULL; PRINT 'Number of rows deleted is ' + CAST(@@ROWCOUNT as char(3)); 以下示例使用名为complex_cursor的游标删除 AdventureWorks2022 数据库的EmployeePayHistory表中的单行。 删除操作只影响当前从游标提取的单行。
Delete Multiple Rows in SQL What if you want to delete multiple rows? Let’s say we wanted to delete all rows where the category is Office. Our statement would look similar: DELETEFROMproductWHEREcategory='Office'; The output would look something like this: ...
http://dev.mysql.com/doc/refman/8.0/en/with.html.Single-TableSyntaxDELETE[LOW_PRIORITY][QUICK][IGNORE]FROMtbl_name[PARTITION (partition_name [, partition_name]...)][WHERE where_condition][ORDER BY ...][LIMIT row_count]TheDELETEstatement deletes rowsfromtbl_nameandreturnsthenumberofdeleted ...
DELETE FROMCORPDATA.EMPLOYEEWHEREWORKDEPT = 'D11'; WHERE 子句告诉 SQL 要从表中删除哪些行。 SQL 从基本表中删除满足搜索条件的所有行。 从视图中删除行将从基本表中删除这些行。 您可以省略 WHERE 子句,但最好包含一个,因为没有 WHERE 子句的 DELETE 语句会从表或视图中删除所有行。 要删除表定义以及表...
where insert_date not in ( select min(insert_date) from films s where f.title = s.title and f.uk_release_date = s.uk_release_date ) This finds, then deletes all the rows that are not the oldest in their group. There is always one oldest row in each batch. So this only removes...
EXPLAIN SELECT * FROM yp_user FORCE INDEX(idx_gender) where gender=1 ; 同样,你也可以通过IGNORE INDEX来忽略索引。 EXPLAIN SELECT * FROM yp_user IGNORE INDEX(idx_gender) where gender=1 ; 在我看来,虽然有MySQL Hints这种好用的工具,但我建议还是不要再生产环境使用,因为当数据量增长时,你压根儿都...
SQL DELETEFROMSales.SalesPersonQuotaHistory; GO Limiting the Rows Deleted Examples in this section demonstrate how to limit the number of rows that will be deleted. B. Using the WHERE clause to delete a set of rows The following example deletes all rows from theProductCostHistorytable in the ...