6– Update using WITH Clause Works with: SQL Server, PostgreSQL (not Oracle, MySQL) You can use a subquery in theWITH clause(called a CTE or Common Table Expression) to update data in one table from another table. WITHsubqueryAS(SELECTaccount_id,account_number,person_idFROMaccount)UPDATEpers...
WITH subquery AS (SELECT column2 FROM table2 WHERE condition) UPDATE table1 SET column1 = subquery.column2 WHERE condition; ``` 4.使用CASE语句更新数据: 在UPDATE语句中使用CASE语句可以根据条件更新不同的值。例如,根据特定条件更新不同的列: ```sql UPDATE table1 SET column1 = CASE WHEN condition...
I seem to have a problem with a Update using a correlated subquery. When I run the following: UPDATE Agtable1 t1 SET t1.ztAddr_Line1 = (select t2.Addr_Line1 from Address t2 where t2.Addr_Type = t1.ztAddr_Type AND t2.Addr_Ident Code1 = t1.ztagree_no ) the subquery is return...
查看慢日志(show [session|gobal] status ),定位慢查询,查看慢查询执行计划根据执行计划确认优化方案 Explain sql select_type:表示select类型。常见的取值有SIMPLE(简单表,即不使用连接或者子查询)、PRIMARY(主查询,即外层的查询)、UNION(union中的第二个或者后面的查询语句)、SUBQUERY(子查询中的第一个SELECT)等。
a versatile way to select data from a database. It can be used to select data based on a list of values or multiple criteria. We also learned that the SQL WHERE IN clause can be used with an array or expression list, or we can add a nested subquery within our SQL WHERE IN clause...
Now, the Select * from Employee query will display the following result. EmpIdFirstNameLastNameEmailPhoneNoSalary 1 'John' 'King' 'jking@test.com' '123.123.1834' 33000 2 'James' 'Bond' 3 'Neena' 'Kochhar' 'neena@test.com' '123.456.4568' 17000 4 'Lex' 'De Haan' 'lex@test.com'...
SELECTemployeeid,COUNT(orderid)FROMordersWHEREshippeddateISNOTNULLGROUPBYemployeeidHAVINGCOUNT(orderid) >100;Code language:SQL (Structured Query Language)(sql) The following query increases the salary of the best sale persons by 5%. The best sale person ids are provided by a subquery. ...
TEST6 (id, name, age, sex, ename, addtime) values ('1', '张三', 18, null, 'zha ...
UPDATE product SET price = ( SELECT MAX(price) * 1.2 FROM product ) WHERE product_id = 1; You can see that the SET clause includes a subquery, which finds the MAX value of the price column in the product table and multiplies it by 1.2 to add 20%. Finally, the WHERE clause is out...
WITH common_table_expression Specifies the temporary named result set or view, also known as common table expression (CTE), defined within the scope of the UPDATE statement. The result set is derived from a SELECT statement and is referenced by the UPDATE statement. For more information, seeWIT...